GIST Support Wiki15 Nov 2007
Subject: XL765 Clinical Trial
Phase I trial of XL765--to determine safety and tolerability. Note phase I trials do NOT have efficacy against a disease as their goal. The drug blocks both PI3K and mTOR....both in the same pathway for cell survival, downstream of KIT.
PI3K is believed to be an important signaling protein in many forms of cancer including GIST. PI3K is activated in GIST by the hyperactivity of mutated KITs. Other cell surface receptors can "feed into" PI3K, so this protein may be activated by redundant stimulation, and thus is a central hub to collect more than one activation signal coming from the cell surface.
While I think a KIT inhibitor is still best for most GIST, this drug could be useful for patients who have mutants in KIT or PDGFRA that seem to be unstoppable by the KIT inhibitors available, or have a wild type GIST, and no one knows what is driving it...
The drug is available in San Antonio and Michigan.
My friend from Tulsa with Leiomyosarcoma is in this trial. Says this drug can cause problems with blood sugar...Feels pretty good and goes walking two miles each day. She does not yet know if the drug is working...she has a CT soon... Marina