THE-630, an investigational therapy for gastrointestinal stromal tumor (GIST), has gained US Food and Drug Administration (FDA) clearance for clinical trials to begin, according to Thesus Pharmaceuticals. THE-630 works as a pan-variant KIT inhibitor.

In recent years, new therapies that treat GIST in a more targeted way have been developed and commercialized. One type of these new therapies targets the KIT mutations in GIST.

In line with these recent medical developments, Thesus Pharmaceuticals has produced a new drug that inhibits the receptor tyrosine kinase KIT and is active against all known variants, according to the company. Tests conducted in vitro demonstrated that THE-630 was effective against all known classes of KIT mutations in GIST, and preclinical studies showed it induced antitumor activity at tolerable doses, the company said.

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The treatment is meant for patients with advanced GIST who might already be resistant to earlier lines of therapy.

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“Patients with previously-treated GIST often have tumors that have developed more than one mutation in KIT that causes resistance to treatment, and we believe treatment with a kinase inhibitor that is active against all relevant mutations—that is, a pan-variant inhibitor—is a promising approach to address this key mechanism of resistance,” Tim Clackson, PhD, the president and chief executive officer of Theseus Pharmaceuticals, explained.

With FDA clearance for clinical trials to begin, Thesus Pharmaceuticals announced it will soon be conducting studies to investigate the effects of this novel drug on GIST patients.

“We look forward to initiating the Phase 1/2 clinical trial and evaluating the potential that THE-630 may offer for patients with advanced GIST who have developed resistance to prior therapy,” Dr. Clackson said.

The clinical trials are set to start between the last quarter of 2021 and the mid-first quarter of 2022.


Theseus Pharmaceuticals announces FDA clearance of Investigational New Drug Application for THE-630, a pan-variant KIT inhibitor in development for the treatment of gastrointestinal stromal tumors (GIST). News release. Theseus Pharmaceuticals; November 1, 2021.