UNITED STATES                                  
                       SECURITIES AND EXCHANGECOMMISSION                        
                              WASHINGTON, DC 20549                              

                                  SCHEDULE 13G                                  

                   Under the Securities Exchange Act of 1934                    
                               (Amendment No. 5)*                               



Syndax Pharmaceuticals, Inc.
      (Name of Issuer)      




Common Stock, par value $0.0001 per share
     (Title of Class of Securities)      




  87164F105   
(CUSIP Number)




                   December 31, 2023                   
(Date of Event Which Requires Filing of this Statement)



Check the appropriate box to designate the rulepursuant to which this Schedule 
is filed:
[_] Rule 13d-1(b)

[X] Rule 13d-1(c)

[_] Rule 13d-1(d)

__________
*The remainder of this cover page shall befilled out for a reporting person's 
initial filing on this form with respect to the subject class of securities, 
and for any subsequentamendment containing information which would alter the 
disclosures provided in a prior cover page.
The information requiredin the remainder of this cover page shall not be 
deemed to be "filed" for the purpose of Section 18 of the Securities 
ExchangeAct of 1934 ("Act") or otherwise subject to the liabilities of that 
section of the Act but shall be subject to all other provisionsof the Act 
(however, see the Notes).




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    Avidity Partners Management LP                                                                  
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    Delaware                                                                                        
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    1                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    IA, PN                                                                                          


___________________

1
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    Avidity Partners Management (GP) LLC                                                            
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    Delaware                                                                                        
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    2                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    OO         


___________________
2
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    Avidity Capital Partners Fund (GP) LP                                                           
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    Delaware                                                                                        
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    3                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    OO, PN                                                                                          


___________________
3
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    Avidity Capital Partners (GP) LLC                                                               
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    Delaware                                                                                        
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    4                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    OO         


___________________
4
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    Avidity Master Fund LP                                                                          
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    Cayman Islands                                                                                  
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    5                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    OO, PN                                                                                          


___________________
5
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    David Witzke                                                                                    
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    United States of America                                                                        
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    6                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    IN                                                                                              



___________________
6
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




CUSIP No. 87164F105  



1.  NAME OF REPORTING PERSONS                                                                       
    I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)                                     
                                                                                                    
    Michael Gregory                                                                                 
                                                                                                    
2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)                             
                                                                                            (a)  [_]
                                                                                            (b)  [X]
                                                                                                    
3.  SEC USE ONLY                                                                                    
                                                                                                    
                                                                                                    
                                                                                                    
4.  CITIZENSHIP OR PLACE OF ORGANIZATION                                                            
                                                                                                    
    United States of America                                                                        
                                                                                                    
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH                                   
                                                                                                    
5.  SOLE VOTING POWER                                                                               
                                                                                                    
    0                                                                                               
                                                                                                    
6.  SHARED VOTING POWER                                                                             
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
7.  SOLE DISPOSITIVE POWER                                                                          
                                                                                                    
    0                                                                                               
                                                                                                    
8.  SHARED DISPOSITIVE POWER                                                                        
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON                                    
                                                                                                    
    3,950,000                                                                                       
                                                                                                    
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)         
                                                                                            [_]     
                                                                                                    
                                                                                                    
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)                                               
                                                                                                    
    4.7%                                                                                            
    7                                                                                               
                                                                                                    
12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)                                                     
                                                                                                    
    IN                                                                                              


___________________
7
The percentage of ownership based on 84,809,736 shares of Common Stock of the 
Company outstanding as of December 19, 2023, as reported on the Issuer's press 
release on December 19, 2023, located at: https://ir.syndax.com/news-releases/ne
ws-release-details/syndax-announces-closing-public-offering-common-stock-and.




Item 1. (a). Name of Issuer:              
                                          
             Syndax Pharmaceuticals, Inc. 



 (b). Address of issuer's principal executive offices: 
                                                       
      35 Gatehouse Drive, Building D, Floor 3          
      Waltham, Massachusetts 02451                     
      United States of America                         



Item 2. (a). Name of person filing:                
                                                   
             Avidity Partners Management LP        
             Avidity Partners Management (GP) LLC  
             Avidity Capital Partners Fund (GP) LP 
             Avidity Capital Partners (GP) LLC     
             Avidity Master Fund LP                
             David Witzke                          
             Michael Gregory                       



 (b). Address or principal business office or, if none, residence: 
                                                                   
      Avidity Partners Management LP                               
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     
                                                                   
      Avidity Partners Management (GP) LLC                         
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     
                                                                   
      Avidity Capital Partners Fund (GP) LP                        
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     
                                                                   
      Avidity Capital Partners (GP) LLC                            
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     
                                                                   
      Avidity Master Fund LP                                       
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     
                                                                   
      David Witzke                                                 
      c/o Avidity Partners Management LP                           
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     
                                                                   
      Michael Gregory                                              
      c/o Avidity Partners Management LP                           
      2828 N Harwood Street, Suite 1220                            
      Dallas, Texas 75201                                          
      United States of America                                     





 (c). Citizenship:                                     
                                                       
      Avidity Partners Management LP- Delaware         
      Avidity Partners Management (GP) LLC - Delaware  
      Avidity Capital Partners Fund (GP) LP - Delaware 
      Avidity Capital Partners (GP) LLC - Delaware     
      Avidity Master Fund LP - Cayman Islands          
      David Witzke - United States of America          
      Michael Gregory - United States of America       



 (d). Title of class of securities:             
                                                
      Common Stock, par value $0.0001 per share 
                                                



 (e). CUSIP No.: 
                 
      87164F105  



Item 3.  If This Statement is filed pursuant to (s)(s).240.13d-1(b) or 240.13d-2(b), or (c), check whether the person filing is a



 (a) [_] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).



 (b) [_] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).



 (c) [_] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).



 (d) [_] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).



 (e) [_] An investment adviser in accordance with (s) 240.13d-1(b)(1)(ii)(E);



 (f) [_] An employee benefit plan or endowment fund in accordance with (s) 240.13d-1(b)(1)(ii)(F);



 (g) [_] A parent holding company or control person in accordance with (s)240.13d-1(b)(1)(ii)(G);



 (h) [_] A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C.1813);



 (i) [_] A church plan that is excluded from the definition of an investment company    
         under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);



 (j) [_] A non-U.S. institution in accordance with (s)240.13d-1(b)(1)(ii)(J);



 (k) [_] Group, in accordance with (s)240.13d-1(b)(1)(ii)(K).  If filing as a non-U.S. institution
         in accordance with (s)240.13d-1(b)(1)(ii)(J), please specify the type of institution:    






Item 4. Ownership.



 Provide the following information regarding the aggregate number and     
 percentage of the class of securities of the issuer identified in Item 1.



 (a) Amount beneficially owned:                      
                                                     
     Avidity Partners Management LP: 3,950,000       
     Avidity Partners Management (GP) LLC: 3,950,000 
     Avidity Capital Partners Fund (GP) LP: 3,950,000
     Avidity Capital Partners (GP) LLC: 3,950,000    
     Avidity Master Fund LP: 3,950,000               
     David Witzke: 3,950,000                         
     Michael Gregory: 3,950,000                      



 (b) Percent of class:                          
                                                
     Avidity Partners Management LP: 4.7%       
     Avidity Partners Management (GP) LLC: 4.7% 
     Avidity Capital Partners Fund (GP) LP: 4.7%
     Avidity Capital Partners (GP) LLC: 4.7%    
     Avidity Master Fund LP: 4.7%               
     David Witzke: 4.7%                         
     Michael Gregory: 4.7%                      



 (c) Number of shares as to which the person has:                                                                    
                                                                                                                     
     (i)   Sole power to vote or to direct the vote                Avidity Partners Management LP: 0                 
                                                                   Avidity Partners Management (GP) LLC: 0          ,
                                                                   Avidity Capital Partners Fund (GP) LP: 0          
                                                                   Avidity Capital Partners (GP) LLC: 0              
                                                                   Avidity Master Fund LP: 0                         
                                                                   David Witzke: 0                                   
                                                                   Michael Gregory: 0                                
                                                                                                                     
     (ii)  Shared power to vote or to direct the vote              Avidity Partners Management LP: 3,950,000         
                                                                   Avidity Partners Management (GP) LLC: 3,950,000   
                                                                   Avidity Capital Partners Fund (GP) LP: 3,950,000  
                                                                   Avidity Capital Partners (GP) LLC: 3,950,000      
                                                                   Avidity Master Fund LP: 3,950,000                 
                                                                   David Witzke: 3,950,000                           
                                                                   Michael Gregory: 3,950,000                        
                                                                                                                     
     (iii) Sole power to dispose or to direct the disposition of   Avidity Partners Management LP: 0                 
                                                                   Avidity Partners Management (GP) LLC: 0          ,
                                                                   Avidity Capital Partners Fund (GP) LP: 0          
                                                                   Avidity Capital Partners (GP) LLC: 0              
                                                                   Avidity Master Fund LP: 0                         
                                                                   David Witzke: 0                                   
                                                                   Michael Gregory: 0                                
                                                                                                                     
     (iv)  Shared power to dispose or to direct the disposition of Avidity Partners Management LP: 3,950,000         
                                                                   Avidity Partners Management (GP) LLC: 3,950,000  .
                                                                   Avidity Capital Partners Fund (GP) LP: 3,950,000  
                                                                   Avidity Capital Partners (GP) LLC: 3,950,000      
                                                                   Avidity Master Fund LP: 3,950,000                 
                                                                   David Witzke: 3,950,000                           
                                                                   Michael Gregory: 3,950,000                        






Item 5. Ownership of Five Percent or Less of a Class.



 If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased
 to be the beneficial owner of more than five percent of the class of securities, check the following [X].     
                                                                                                               
                                                                                                               
                                                                                                               




Item 6. Ownership of More Than Five Percent on Behalf of Another Person.



 If any other person is known to have the right to receive or the      
 power to direct the receipt of dividends from, or the proceeds from   
 the sale of, such securities, a statement to that effect should be    
 included in response to this item and, if such interest relates to    
 more than 5 percent of the class, such person should be identified.   
 A listing of the shareholders of an investment company registered     
 under the Investment Company Act of 1940 or the beneficiaries of      
 employee benefit plan, pension fund or endowment fund is not required.
                                                                       
 N/A                                                                   
                                                                       



Item 7. Identification and Classification of the Subsidiary Which Acquired the     
        Security Being Reported on by the Parent Holding Company or Control Person.



 If a parent holding company or control person has filed this schedule, pursuant to Rule 13d-1(b)(1)(ii)(G),
 so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of    
 the relevant subsidiary. If a parent holding company or control person has filed this schedule pursuant to 
 Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.   
                                                                                                            
 N/A                                                                                                        
                                                                                                            



Item 8. Identification and Classification of Members of the Group.



        If a group has filed this schedule pursuant to (s)240.13d-1(b)(1)(ii)(J), so indicate  
        under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of
        each member of the group. If a group has filed this schedule pursuant to Rule 13d-1(c) 
        or Rule 13d-1(d), attach an exhibit stating the identity of each member of the group.  
                                                                                               
        N/A                                                                                    
                                                                                               
Item 9. Notice of Dissolution of Group.                                                        



 Notice of dissolution of a group may be furnished as an exhibit stating
 the date of the dissolution and that all further filings with respect  
 to transactions in the security reported on will be filed, if required,
 by members of the group, in their individual capacity. See Item 5.     
                                                                        
 N/A                                                                    
                                                                        



Item 10. Certification.



 By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not  
 acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer
 of the securities and were not acquired and are not held in connection with or as a participant in any transaction  
 having that purpose or effect, other than activities solely in connection with a nomination under (s) 240.14a-11.   




                                   SIGNATURE                                    

After reasonable inquiry and to the best of my knowledge and belief, 
theundersigned certify that the information set forth in this statement is 
true, complete and correct.


 February 14, 2024                                                                      
 (Date)                                                                                 
                                                                                        
 David Witzke                                                                           
 Avidity Partners Management LP                                                         
 Avidity Partners Management (GP) LLC                                                   
 Avidity Capital Partners Fund (GP) LP                                                  
 Avidity Capital Partners (GP) LLC                                                      
 Avidity Master Fund LP                                                                 
                                                                                        
 By: /s/ David Witzke                                                                   
 David Witzke, for himself and as Managing Member of Avidity Partners Management (GP)   
 LLC (for itself and as general partner of Avidity Partners Management LP) and Avidity  
 Capital Partners (GP) LLC (for itself and as general partner of Avidity Capital        
 Partners Fund (GP) LP (for itself and as general partner of Avidity Master Fund LP))   
                                                                                        
 Michael Gregory                                                                        
 Avidity Partners Management LP                                                         
 Avidity Partners Management (GP) LLC                                                   
 Avidity Capital Partners Fund (GP) LP                                                  
 Avidity Capital Partners (GP) LLC                                                      
 Avidity Master Fund LP                                                                 
                                                                                        
 By: /s/Michael Gregory                                                                 
 Michael Gregory, for himself and as Managing Member of Avidity Partners Management (GP)
 LLC (for itself and as general partner of Avidity Partners Management LP) and Avidity  
 Capital Partners (GP) LLC (for itself and as general partner of Avidity Capital        
 Partners Fund (GP) LP (for itself and as general partner of Avidity Master Fund LP))   



The original statement shall be signed by eachperson on whose behalf the 
statement is filed or his authorized representative. If the statement is 
signed on behalf of a person by hisauthorized representative other than an 
executive officer or general partner of the filing person, evidence of the 
representative's authorityto sign on behalf of such person shall be filed with 
the statement, provided, however, that a power of attorney for this purpose 
whichis already on file with the Commission may be incorporated by reference. 
The name and any title of each person who signs the statementshall be typed or 
printed beneath his signature.
Note. Schedules filed in paper format shallinclude a signed original and five 
copies of the schedule, including all exhibits. See s.240.13d-7 for other 
parties for whom copies areto be sent.
Attention. Intentional misstatements or omissionsof fact constitute Federal 
criminal violations (see 18 U.S.C. 1001).



Exhibit 1
                             JOINT FILING AGREEMENT                             
In accordance with Rule13d-1(k) under the Securities Exchange Act of 1934, as 
amended, the persons named below agree to the joint filing on behalf of each 
ofthem of a Statement on Schedule 13G (including amendments thereto) with 
respect to the Common Stock of Syndax Pharmaceuticals, Inc.,and further agree 
that this Joint Filing Agreement be included as an Exhibit to such joint filing

The undersigned furtheragree that each party hereto is responsible for the 
timely filing of such Statement on Schedule 13G and any amendments thereto, 
and forthe accuracy and completeness of the information concerning such party 
contained therein; provided, however, that no party is responsiblefor the 
accuracy or completeness of the information concerning any other party, unless 
such party knows or has reason to believe thatsuch information is inaccurate.
IN WITNESS WHEREOF, theundersigned hereby execute this Agreement as of 
February 14, 2024.

 David Witzke                                                                             
 Avidity Partners Management LP                                                           
 Avidity Partners Management (GP) LLC                                                     
 Avidity Capital Partners Fund (GP) LP                                                    
 Avidity Capital Partners (GP) LLC                                                        
 Avidity Master Fund LP                                                                   
                                                                                          
                                                                                          
 /s/ David Witzke                                                                         
 David Witzke, for himself and as Managing Member of Avidity Partners Management (GP)     
 LLC (for itself and as general partner of Avidity Partners Management LP) and Avidity    
 Capital Partners (GP) LLC (for itself and as general partner of Avidity Capital          
 Partners Fund (GP) LP (for itself and as general partner of Avidity Master Fund LP))     
                                                                                          
 Michael Gregory                                                                          
 Avidity Partners Management LP                                                           
 Avidity Partners Management (GP) LLC                                                     
 Avidity Capital Partners Fund (GP) LP                                                    
 Avidity Capital Partners (GP) LLC                                                        
 Avidity Master Fund LP                                                                   
                                                                                          
 By:                           /s/ Michael Gregory                                        
 Michael Gregory, for himself and as Managing Member of Avidity Partners Management (GP)  
 LLC (for itself and as general partner of Avidity Partners Management LP) and Avidity    
 Capital Partners (GP) LLC (for itself and as general partner of Avidity Capital          
 Partners Fund (GP) LP (for itself and as general partner of Avidity Master Fund LP))