The market punished APTO (down ~32%) on its EHA21 presentation (SEE HERE) on its lead asset, Luxeptinib, in certain blood cancers. We discussed the event in detail in this blog post (SEE HERE).
Furthermore, AMP provides a more in depth response post to the APTO EHA21 data in our forum for subscribers (SEE HERE)*, including AMP's decision with respect to whether it will hold its shares of APTO stock going forward.
Now the questions for investors: Did Market Over-React to the Luxeptinib data? Or is APTO too late with its BtK and FLT3 inhibitor?
The bull case goes as follows:
The market over-reacted: APTO continues to demonstrate that Luxeptinib is a promising drug candidate that might be unique in its ability to effectively knock down Btk, FLT3, and SYK activity with an acceptable safety/tolerability. APTO has now demonstrated activity in a CLL patient with over 20% decrease in tumor burden and over 20% reduction in IgM in a Non-Hodgkin's Lymphoma patient.
Even at these high doses, Lux has not produced a dose-limiting toxicity. Thus, it can be dosed up more, which might provide even more efficacy as other kinases that require more Lux for inhibition, are inhibited. Furthermore, for patients whose tumors continue to increase for weeks after initial dosing, it is worth continued dosing because some of these patients will likely respond with more time on drug. Even if there are quite a few Btk and FLT3 inhibitors later in development or approved, there will be room for Lux for a significant market share of patients who fail all other therapeutic options, where, as APTO has now demonstrated, Lux can help significantly reduce tumor burden.
In sum, APTO's current trials for Lux enroll heavily pretreated relapsed/refractory patients, many of whom have relapsed after prior Btk inhibitor therapy. The fact that Lux shows activity in some of these patients is impressive proof of concept data for Lux and its differentiated mechanism because of its differentiated kinase profile. With more time and even higher dosing, responses will deepen in more patients and the drug will eventually make its way to market and provide another option for AML and B cell cancer patients who have previously relapsed on many other options.
APTO included some new efficacy data that in our view was among the most impactful data it has presented. See AMP's forum post (SEE HERE)* for not only a discussion of this new efficacy data but also for the bear case for APTO. Plus, AMP's forum post gives their decision on whether to hold or sell their APTO shares going forward.
*BPIQ Pro or free 30 day trial required -click here to sign up and get access)
