UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
_____________________

Form 8-K
_____________________

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event Reported): April 27, 2020  

Aptose Biosciences Inc.
(Exact Name of Registrant as Specified in Charter)

Canada001-3200198-1136802
(State or Other Jurisdiction of Incorporation)(Commission File Number)(I.R.S. Employer Identification Number)

 

251 Consumers Road, Suite 1105, Toronto, Ontario, Canada M2J 4R3
(Address of Principal Executive Offices) (Zip Code)

647-479-9828
(Registrant's telephone number, including area code)


(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

 [   ]  Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
 [   ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
 [   ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
 [   ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

 

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2). Emerging growth company [ X ]

 

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. [ X ]

 

Securities registered pursuant to Section 12(b) of the Act:

 

Title of each classTrading Symbol(s)Name of each exchange on which registered
Common Shares, no par valueAPTONasdaq Capital Market
 
 

Item 8.01. Other Events.

On April 27, 2020, the Registrant issued a press release, a copy of which is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

In accordance with General Instruction B.2 of Form 8-K, the information in the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Item 9.01. Financial Statements and Exhibits.

Exhibit 99.1. Press release dated April 27, 2020


SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

 Aptose Biosciences Inc.
   
  
Date: April 27, 2020By: /s/ Gregory K. Chow        
  Gregory K. Chow
  Senior Vice President and Chief Financial Officer
  

EdgarFiling

EXHIBIT 99.1

Aptose Presents Preliminary Clinical Data on CG-806 at AACR Virtual Annual Meeting 2020

Data from patients at first two dose levels; Phase 1a/b study is ongoing

SAN DIEGO and TORONTO, April 27, 2020 (GLOBE NEWSWIRE) -- Aptose Biosciences Inc. (Nasdaq: APTO; TSX: APS), a clinical-stage company developing highly differentiated therapeutics that target the underlying mechanisms of cancer, today presented the early clinical data on CG-806, the company’s oral, first-in-class FLT3/BTK cluster selective kinase inhibitor, at the AACR Virtual Annual Meeting I (April 27-28), in lieu of the live oral presentation originally planned. 

Rafael Bejar M.D., Ph.D., Aptose’s Chief Medical Officer, presented a video summary of Abstract # 9967 - Early clinical findings from a phase 1a/b dose escalation trial to evaluate the safety and tolerability of CG-806 in patients with relapsed or refractory CLL/SLL or non-Hodgkin’s lymphomas [link].

The first-in-human tests of CG-806 are being carried out in a Phase 1a/b clinical study. The target population in the study includes patients with significant unmet needs including patients with relapsed or refractory chronic lymphocytic leukemia (CLL), small lymphocytic leukemia (SLL) or non-Hodgkin lymphoma (NHL) who have failed or been intolerant to two lines of established therapy. CG-806 is administered as oral capsules dosed twice daily in 28-day cycles. The study design includes an accelerated titration followed by a 3+3 dose escalation to establish the recommended Phase 2 dose for planned expansion cohorts and future studies.

The first patient, treated with 150 mg BID of CG-806, was heavily pretreated, carried a TP53 mutation, and had severe thrombocytopenia prior to study entry. This patient currently is in the eleventh cycle of therapy without having experienced a dose-limiting toxicity (DLT) and has been dose escalated to the 450 mg BID dose level.

The second patient, treated at the 300 mg BID dose level, had significant marrow involvement with neutropenia and thrombocytopenia at study entry, and developed a brisk lymphocytosis, but did not experience a DLT through four cycles of therapy including no worsening of their thrombocytopenia or neutropenia.

The study has now completed three dose levels without observing any drug-related severe adverse events (SAE) and has not reached a dose-limiting toxicity. Three patients completed the safety evaluation period at the third dose level, 450 mg BID, and as a result, the fourth dose level was opened.  The first patient, previously dosed at 150 mg BID was dose escalated to dose level 3 at 450 mg BID. Enrollment is open and dosing is ongoing at the 600 mg BID dose level with no drug-related SAEs or DLTs encountered to date.

Key findings to date:

Dr. Bejar summarized the team’s findings: “CG-806 is a novel and unique cluster selective kinase inhibitor with activity against clinically validated targets in both lymphoid and myeloid malignancies through its potent inhibition of BTK and FLT3. The ongoing Phase 1 study in relapsed/refractory B-cell malignancies has demonstrated the safety of CG-806 to date, pharmacologic activity, and predictable pharmacokinetic behavior. We look forward to presenting new data from higher dose cohorts at a future medical meeting.” 

The slide deck of this presentation is available on the Aptose website https://www.aptose.com/product-pipeline/posters-presentations.

About CG-806

CG-806 is an oral, first-in-class FLT3/BTK cluster selective kinase inhibitor and is in Phase 1 clinical studies for the treatment of hematologic malignancies. This small molecule, demonstrates potent inhibition of wild type and all mutant forms of FLT3 (including internal tandem duplication, or ITD, and mutations of the receptor tyrosine kinase domain and gatekeeper region), cures animals of AML in the absence of toxicity in murine xenograft models, and represents a potential best-in-class therapeutic for patients with AML and other myeloid malignancies. Likewise, CG-806 demonstrates potent, non-covalent inhibition of the wild type and Cys481Ser (C481S) mutant forms of the BTK enzyme, as well as other oncogenic kinase pathways operative in B cell malignancies, suggesting CG-806 may be developed for various B cell malignancy patients (including CLL/SLL, FL, MCL, DLBCL and others) that are resistant/refractory/intolerant to covalent or other non-covalent BTK inhibitors. Because CG-806 targets key kinases/pathways operative in malignancies derived from the bone marrow, it is in development for B-cell cancers and AML.

About Aptose Biosciences

Aptose Biosciences is a clinical-stage biotechnology company committed to developing personalized therapies addressing unmet medical needs in oncology, with an initial focus on hematology. The Company's small molecule cancer therapeutics pipeline includes products designed to provide single agent efficacy and to enhance the efficacy of other anti-cancer therapies and regimens without overlapping toxicities. The Company has two clinical-stage investigational products for hematologic malignancies: CG-806, an oral, first-in-class mutation-agnostic FLT3/BTK kinase inhibitor, is in a Phase 1 trial in patients with relapsed or refractory B cell malignancies, including chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL) and non-Hodgkin lymphoma (NHL), who have failed or are intolerant to standard therapies; APTO-253, the only clinical stage agent that directly targets the MYC oncogene and suppresses its expression, is in a Phase 1b clinical trial for the treatment of patients with relapsed or refractory acute myeloid leukemia (AML) or high risk myelodysplastic syndrome (MDS). For further information, please visit www.aptose.com

For further information, please contact:

Aptose Biosciences Inc.
Greg Chow 
Executive Vice President, CFO 
650-718-5028 
gchow@aptose.com
LifeSci Advisors, LLC
Dan Ferry, Managing Director
617-535-7746
Daniel@LifeSciAdvisors.com
  
SMP Communications
Susan Pietropaolo
201-923-2049
susan@smpcommunications.com