In a first-in-human, dose-escalation Phase 1 clinical trial, researchers are evaluating cosibelimab (CK-301) as a potential therapeutic option for those with metastatic cutaneous squamous cell carcinoma (cSCC). So far, shares Cancer Network, the study has actually met its primary endpoint in terms of response rate. Although additional research is needed, the study highlights the benefits of cosibelimab for cSCC. Ultimately, this could help provide another accessible and effective therapeutic options for patients. 

To learn more about the preliminary findings, you can take a look at Poster 1084P from Checkpoint Therapeutics.

About Cosibelimab

According to Checkpoint Therapeutics, cosibelimab is: 

an investigational fully-human monoclonal antibody that binds programmed death-ligand 1 (PD-L1) and blocks its interaction with Programmed cell death protein 1 (PD-1).

Cosibelimab’s primary mechanism of action is based on the inhibition of the interaction between PD-L1 and its receptor PD-1, which removes the suppressive effects of PD-L1 on anti-tumor T-cells to restore the cytotoxic T-cell response.

Within this Phase 1 study, 78 patients with cSCC enrolled. Although there was an additional cohort of 201 patients with other cancers, we are going to (for the most part) focus on cSCC. Next, patients received 800mg cosibelimab every 2 weeks. Findings include:

• Cosibelimab was found to be relatively safe and well-tolerated. However, some adverse reactions did occur. These included nausea, anemia (low red blood cell count), fatigue, and rashes.
• The overall response rate of the entire trial was 47.4%, with the response rate within the cSCC cohort sitting at 55%. Many patients also saw durable and sustained responses to treatment, and at least 5 of those with cSCC had a complete response.

In the future, more research will be done, including a Phase 3 clinical trial evaluating cosibelimab in conjunction with other therapies.

What is Cutaneous Squamous Cell Carcinoma (cSCC)?

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer within the United States. This cancer affects the middle and outer skin layers, and is often found on areas of the skin with high sun exposure. As this may suggest, UV exposure can heighten the risk of developing cSCC. Other risk factors include a history of sunburns, tanning bed use, fair skin, a weakened immune system, having a rare genetic disorder, or having a history of precancerous lesions or skin cancer. Symptoms include:

• Rough, thickened, or wart-like skin
• Mouth sores
• Anal or genital sores
• New sores formed on old scars
• Scaly red patches
• Raised growths with a central depression that may itch, bleed, or crust over