Clovis Oncology (NASDAQ:CLVS) announced today updated findings from the Phase I portion of its ongoing Phase I/II clinical study of CO-1686, the Company’s novel, oral, targeted covalent (irreversible) inhibitor of mutant forms of the epidermal growth factor receptor (EGFR) for the treatment of non-small cell lung cancer (NSCLC) in patients with initial activating EGFR mutations as well as the dominant resistance mutation T790M. Interim results from the Phase I dose-escalation portion of this Phase I/II study are being presented today in an oral presentation by Professor Jean-Charles Soria at the IASLC 15 th World Conference on Lung Cancer in Sydney.
Six RECIST partial responses have been observed to date in nine evaluable T790M positive patients dosed at 900mg BID of the free base formulation, for a 67 percent objective response rate. Eight of the nine evaluable patients, or 89 percent, experienced tumor shrinkage greater than 10 percent. Fifty-six patients have been treated with CO-1686 to date across all dosing cohorts, with no evidence of systemic wild-type EGFR-driven toxicities such as rash. Dose escalation is ongoing with the improved HBr formulation, currently dosing at 750mg BID, as the maximum tolerated dose (MTD) has not yet been reached.
“These results are exciting, and confirm and extend the initial data reported at ASCO 2013 for this new agent,” said Professor Jean-Charles Soria, Professor of Medicine and Medical Oncology at Paris University XI and cancer specialist at Gustave Roussy Institute. “The T790M acquired resistance mutation is a critical problem in mutant-EGFR lung cancer patients, and CO-1686 appears to be meaningfully benefiting these patients, without triggering the skin and GI toxicities typically seen with older EGFR inhibitors that are not mutant-selective.”
“CO-1686 continues to demonstrate impressive activity and is very well tolerated in these heavily pre-treated patients,” said Patrick J. Mahaffy, president and CEO of Clovis Oncology. “Additionally, the initial pharmacokinetic and safety data from patients in the ongoing Phase I dose-finding study with the hydrobromide formulation are very promising. We are very optimistic about this new formulation since we are already seeing such encouraging results with an inferior formulation at a suboptimal dose. We look forward to identifying the recommended Phase II dose for CO-1686 and quickly proceeding into our first registration study.”