Clarification On Cg-806 Phase 1 Plans

KSS, $APTO Board Member Denis Burger, SVP/CFO Greg Chow, and CEO William Rice. Wainwright Global Bio, JW Marriott Grosvenor Square, Mayfair, London, 9 April 2019. Photo by Allan Lee.

LONDON: In follow up to certain thread discussion last night about Aptose’s immediate clinical trial plans, let us issue a certain clarification we ourselves were unaware of until meeting with Dr. Rice yesterday at Wainwright.

Instead of parallel HVS and lymphoma study initiation, the company now first plans to begin dosing CG-806 to select B-cell lymphoma patients in phase 1. Doses will vary over a narrow range with intensive PK and PD monitoring. Dr. Rice says it is very possible the company can garner the PK information it needs from this approach in order to know how to “hit the ground running” in phase 1 AML….in other words to know how to dose AML patients. He thinks the dose will likely be 150 mg twice daily vs 300 mg once daily (and those ARE different dosing regimens). This approach may obviate the need for an HVS because late preclinical work has made the implied human dose of CG-806 clearer than it was weeks back when we last touched on this subject.

The company does not plan immediately to launch an HVS….and avoiding an HVS would save funds as well. An HVS has not been back-burnered, but RIce and CMO Steven Howell, MD, would simply like to study what’s going on with dosed lymphoma patients. The sentiment we got was that perhaps the two-pronged approach makes the initial development more complex than it needs to be. And most B-cell lymphoma patients feel fairly well on a daily basis and have relatively slow progressing indolent disease. They are an excellent phase 1 exploratory population.

This study protocol was recently posted: https://clinicaltrials.gov/ct2/show/NCT03893682?term=aptose&rank=2

A good night of rest to all. Allan Lee and I have a day of follow-ups and add-on conferences in London, where the sky grows pink.