Skin cancer shot cleared many early tumors, with only mild side effects

If you have ever dreaded the idea of skin cancer surgery and the scar it can leave, here is encouraging news. Researchers injected a tiny dose of an immunotherapy medicine straight into early skin cancers, and in many of the treated spots, no cancer was left.

The skin cancer in this study is squamous cell carcinoma, one of the most common kinds. Small, early ones are usually cut out. Surgery works well, but it can leave scars, especially on the face. A treatment that clears the tumor without a scalpel is a real step forward.

How the study worked

Doctors treated 41 people who had early squamous cell skin cancer, with tumors 1 to 2 centimeters across (up to about three-quarters of an inch). Each person had one tumor injected with a medicine called cemiplimab. It was an open-label phase 1 pilot study, which means everyone knew they were getting the medicine and the main goal was to check safety. The first groups tried 5, 15 and 44 mg weekly for 12 weeks. Then two larger groups got 5 mg, either weekly or every two weeks, for 6 weeks. Doctors looked at the tumors at weeks 7 and 13, and at week 13 the area was removed with surgery so it could be checked under a microscope. The results were published Oct. 30, 2026, in the Journal of the American Academy of Dermatology, and the study was small, with no comparison group, and the injections could have varied from person to person.

What they found

The medicine was safe enough for the researchers to call its safety profile acceptable. In the two 5 mg groups, every treatment-related side effect was mild or moderate (grade 2 or lower).

And it worked in many people. In the group that got 5 mg every week, about 6 in 10 people had no cancer left, whether doctors looked at the skin or checked it under the microscope. The exact figure was 58.3% for both.

In the group that got 5 mg every two weeks, about 4 in 10 had no visible tumor (41.7%), and about 2 in 3 had no cancer under the microscope (66.7%).

The microscope result is the one doctors trust most, because a tumor can look gone on the surface while some cancer cells remain. In both groups, more than half of the tumors came back clear on that test.

What is cemiplimab, and what comes next?

Cemiplimab is an immunotherapy. It takes the brakes off your immune system so your body can go after cancer cells. It is usually given through an IV for advanced skin cancer. Here, it went straight into the tumor at a much lower dose, so the fight happens right where the cancer is.

The researchers say these results support more study of the 5 mg weekly schedule. For now, this is still an experimental approach, and surgery remains the standard treatment for early squamous cell skin cancer. Down the road, an option like this could help people for whom surgery is harder, such as those who take blood thinners or have tumors in tricky spots.

What you can do today

The best news here is that early skin cancers are small and treatable, and finding them early is something you can do yourself. Take two minutes this morning to look over your skin. Use a mirror for your back, or ask someone at home to check it for you. Look for a spot that is new, growing, scaly or bleeding. If you find one, book a visit with a dermatologist and let them take a look.