Cosibelimab Elicits Positive Tumor Response in Patients With Metastatic Skin Cancer Subtype

A clinical trial assessing the efficacy of cosibelimab in patients with metastatic cutaneous squamous cell carcinoma (cSCC), the second most common type of skin cancer, met its primary goals and the drug is on track to be submitted to the U.S. Food and Drug Administration (FDA) for a Biologics License Application (BLA) – which would introduce the drug into the American market – later this year.

“These impressive results demonstrate that cosibelimab, a novel PD-L1 antibody with a unique two-fold mechanism of action, has the potential to offer physicians a new treatment option that provides compelling efficacy, complemented by a favorable tolerability profile, for patients living with this devastating disease,” said Dr. Philip Clingan, a medical oncologist at Southern Medical Day Care Centre in Australia and co-principal investigator on the trial, in a press release.

The main goal of the study was to measure the objective response rate (ORR), which shows how well the tumor is responding to treatment. The ORR in the trial was 47.4%, based on data from 78 patients with metastatic cSCC who were treated with 800 mg of cosibelimab every two weeks. Median duration of response (DOR) was not yet reached at time of data cutoff.

“We believe the strong ORR result is attributable to cosibelimab’s differentiated, two-fold mechanism of action of engaging both T-cells and natural killer cells, while also demonstrating a potential favorable safety profile through its binding to PD-L1, reported in literature as associated with lower rates of severe or worse adverse events as compared to PD-1 therapy,” said James F. Oliviero, president and chief executive officer of Checkpoint Therapeutics, Inc. — the company developing the drug.

The patients were evaluated for trial enrollment using the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 — a standardized set of rules that provide a framework for response assessment using tumor shrinkage.

“Most people don’t realize that cutaneous squamous cell carcinoma is the second most common form of skin cancer,” Clingan said. “While treatable with surgery when caught early, cSCC patients diagnosed with advanced disease that has recurred or metastasized have traditionally faced a poor prognosis and often suffer from painful physical discomfort.”

Among 201 patients with advanced cancers who were treated in all groups of the ongoing study, data were consistent with what had been reported previously — with mostly mild or moderate treatment-related side effects.

If cosibelimab is approved by the FDA, Checkpoint Therapeutics noted that it intends to offer it at a more affordable price than other available PD-L1 therapy options to patients. Moreover, and the manufacturer noted it believes it could be a possible option for use in combination regimens.

Checkpoint Therapeutics is still enrolling patients with locally advanced cSCC for treatment with cosibelimab, in hopes that it could be included in the planned BLA submission along with the phase 3 CONTERNO trial evaluating cosibelimab with pemetrexed and platinum chemotherapy.

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