Aptose Shares Fall After HM43239 Data Featured At ASH Annual Meeting, Luxeptinib, APTO-253 Update

Aptose Biosciences Inc (NASDAQ: APTO) presented data from the ongoing Phase 1/2 study of HM43239 in patients relapsed or refractory acute myeloid leukemia (AML) who had received at least one prior line of therapy.

• Data were presented at the American Society of Hematology (ASH) Annual meeting.
• Among FLT3 mutant patients treated with 80 mg, 3 of 8 (37.5%) achieved a durable composite complete response (CRc).
• At the 80 mg dose, a composite CRc rate of 25% was observed in both FLT3 mutant and FLT3 wild-type AML.
• At the 80 mg dose, 4 of 5 (80%) responders advanced to HSCT.
• Recently, another prior gilteritinib failure patient achieved PR after one cycle at the 120 mg dose.
• HM43239 showed a favorable safety profile with mild adverse events, no dose-limiting Toxicities up to 160 mg per day, and no drug discontinuations from drug-related toxicity.
• The dose-escalation cohorts of 200 mg and the dose-expansion cohorts of 120 and 160 mg are currently enrolling.
• In addition, clinical data for luxeptinib and APTO-253 were presented at ASH. 
• Aptose expects to begin testing a new formulation of luxeptinib in the ongoing studies in patients with hematologic malignancies in 1H 2022.
• Additionally, Aptose has started exploring strategic alternatives to develop APTO-253 in hematologic malignancies and solid tumors.
• Related Link: Aptose Biosciences Stock Tumbles As Luxeptinib Fails To Impress At EHA2021 Virtual Congress.
• Price Action: APTO shares are down 27.70% at $1.41 during the premarket session on the last check Tuesday.
• Check out our coverage of the American Society of Hematology (ASH) Annual Meeting 2021 here.