Checkpoint Therapeutics announced that its checkpoint inhibitor cosibelimab is showing positive objective response rate data in patients with locally advanced cutaneous squamous cell carcinoma.
Checkpoint Therapeutics is prepping for a conversation with the U.S. Food and Drug Administration regarding the potential for a second possible indication for its experimental anti-PD-L1 antibody, cosibelimab, based on positive interim efficacy results in a type of carcinoma.
On Thursday, Waltham, MA-based Checkpoint Therapeutics announced that cosibelimab, a chekpoint inhibitor, is showing positive objective response rate data in patients with locally advanced cutaneous squamous cell carcinoma (cSCC) who are not candidates for curative surgery or radiation. The interim data shows an ORR of 54.8%. Checkpoint said this data “substantially” exceeded a clinically meaningful lower bound of the 95% two-sided confidence interval of 25%.
Based on these results, Checkpoint said it intends to continue discussions with the FDA on the potential addition of locally advanced cSCC as a second indication in the planned Biologics License Application (BLA) targeted for submission later this year.
Cosibelimab is a potential best-in-class, high affinity, fully-human monoclonal antibody of IgG1 subtype that directly binds to programmed death ligand-1 and blocks the PD-L1 interaction with the programmed death receptor-1, as well as B7.1 receptors. This interaction removes the suppressive effects of PD-L1 on anti-tumor CD8+ T-cells in order to restore the cytotoxic T cell response, the company said.
The data announced Thursday builds on previously reported positive top-line data from a cohort of 78 patients diagnosed with metastatic cSCC in Checkpoint’s pivotal trial of cosibelimab. In that study, Checkpoint’s inhibitor reported a confirmed objective response rate of 47.4%. It was based on this data that Checkpoint announced its intention to submit a Biologics License Application to the FDA later this year.
James Oliviero, president and chief executive officer of Checkpoint Therapeutics, called the interim results “exciting.” He said the interim results in this cohort of patients suggest a potential second indication for cosibelimab in locally advanced cSCC when taken into context with the potential approval of the drug candidate in the metastatic cSCC setting. Oliviero speculated that this could double the market opportunity at launch for cosibelimab globally.
“Locally advanced cSCC occurs when tumors become large or have grown deep into underlying tissues, muscles, or nerves, destroying nearby healthy tissue, but have not yet spread metastatically to the lymph nodes or other distant locations of the body,” Oliviero said in a statement.
He suggested that cosibelimab has the potential to differentiate itself from currently approved checkpoint inhibitors, such as Merck’s Keytruda or Bristol Myer Squibb’s Opdivo due to a two-fold mechanism of action he said could deliver robust efficacy with a potentially more favorable safety profile due to its binding to PD-L1 rather than PD-1.
“Based on this compelling clinical profile, our planned market-disruptive pricing, and our patent protection through at least 2038, we believe cosibelimab has the opportunity to gain meaningful market share in the $32 billion and growing anti-PD-(L)1 class, while significantly lowering the barrier of high out-of-pocket costs patients endure worldwide to access existing premium-priced cancer therapies,” he said.
