Aptose Biosciences Inc (APTO)

[Tartiaboy]

My objective for listing them is to recognize that they do not a priori prevent a CR with TUSP. Of course the context and co-mutations probably affect the outcome. "Tusp targets NPM1 mutations only in patients with Flt3 co-mutations." I don't think that is a valid assumption. We don't have any data, just the absence of a Fltwt, Npm1 co-mutation among the current CRs. Future patients with Fltwt, NPM1 may show a CR (we'll see). Whether the monotherapy strategy will settle on previous Flt3i failures, TP53mut, RASmut, or NPM1mut is yet to be determined. That is the main goal of the expansion phase. Regarding DoR. I think APTO should not have posted that six month goal for several reasons. First these AMLr/r patients have an average survival of only a few months. Second they are going into HSCT ASAP if they qualify. I don't believe that any CR patient that qualifies will stay on TUSP for six months prior to HSCT. APTO knows this. That's why they discussed the strategy of treat with TUSP, achieve a CR, expect HSCT, then follow with TUSP for maintenance. This is the strategy they discussed in the Dec 6 webcast and this is the strategy I expect them to propose to the FDA. All of this is fine as part of the AA monotherapy plan, but I still believe the big breakthrough CRs will be seen in combinations and that the real benefits will be first and second line use.

I also expect Lux to re-emerge in a big way in 2023. 1 microM plasma levels may be a bit too low for monotherapy efficacy. I do not believe it is too low for combinations. We already know we can achieve 1 microM levels.