Aptose Biosciences Inc. (NASDAQ:APTO) has announced the dosing of the first acute myeloid leukemia (AML) patient in Phase 1 a/b CG-806 clinical study.
CG-806 inhibits FLT3 and BTK mutant forms in AML patients
CG-806 is the company’s oral kinase inhibitor, which strongly inhibits the mutant forms of BTK and FLT3 and suppresses select Kinases clusters that drive oncogenic signaling pathways. This experimental drug is the only known clinical component that inhibits BTK and FLT3, thus giving its wide therapeutic potential in the spectrum of myeloid and lymphoid hematological malignancies.
William Rice, the CEO and President of the company, said that they thoughtfully and diligently prepared for the trial, and they are delighted to treat refractory or relapsed AML patients with CG-806. The company settled for the 450 mg starting dose in AML patients because the dose when given to CLL patients treated in separate Phase 1 a/b trails showed favorable safety and tolerability profile. It achieved plasma exposure levels effectively inhibiting phosphor-FLT3 activity, which is the main AML driver.
So far, several clinical sites are screening subjects for Phase 1 a/b open-label, multicentre, dose-escalation trials of safety, pharmacokinetics, and pharmacodynamics of CG-806 in ascending cohorts. The study has been designed to determine the maximum tolerated dose or the recommended doses in refractory or relapsed AML patients.
Aptose testing CG-806 in other malignancies
Besides the AML trial, the company is also conducting a phase 1 a/b dose-escalation study with CG-806 in patients with b-cell malignancies, including non-Hodgkin’s lymphomas (NHL) and chronic lymphocytic leukemia that are intolerant or have failed current therapies.
Also, CG-806 has shown the potential of strong, non-covalent inhibition in Cys481Ser mutant and wild type forms of BTK enzymes and other oncogenic kinases pathways in B-Cell malignancies. This suggests that this best in class therapeutic can be developed in treating patients with B-Cell malignancies that are resistant or intolerant to non-covalent and covalent BTCK inhibitors. This is because CG-806 targets main pathways/kinases operative in bone marrow-derived malignancies, and it is in development for AML and B-cell cancers.