Cancer immunotherapy research round-up

Joana Osorio in Nature:

Melanoma: Personal vaccines and virus therapy

NaturePersonalized vaccines and viruses that infect and destroy cancer cells can help the immune system to build up a strong and specific attack against skin cancers. Melanoma cells typically carry many mutations, which results in the production of altered proteins not present in healthy cells. Vaccines against such tumour-specific proteins stimulate the immune system to target and destroy the malignant cells. Patrick Ott at the Dana-Farber Cancer Institute in Boston, Massachusetts, and his colleagues created personalized vaccines that each included 20 altered peptides present in tumours of individuals at high risk of melanoma recurrence. Of six people vaccinated, four remained free of tumours 25 months later. The cancer recurred in the remaining two, but completely regressed after therapy with PD-1 inhibitors — antibodies to the cell-surface protein programmed cell death protein 1 (PD-1) that block the damping down of immune responses and so prevent cancer cells from avoiding destruction.

Ugur Sahin at BioNTech in Mainz, Germany, and his collaborators vaccinated 13 people with RNA molecules encoding up to 10 peptides specific to their individual melanomas. After 12–23 months, 8 individuals were cancer-free. In two other patients, tumours regressed after vaccination, and in one more patient, after vaccination and treatment with a PD-1 inhibitor. Antoni Ribas at the University of California, Los Angeles, and an international team treated 21 patients who had advanced melanoma with injections of an oncolytic virus into the tumour, followed by combined therapy with a PD-1 inhibitor. The virus attracted immune cells to the tumour, and the inhibition of PD-1 boosted immune activity throughout the body. Patients tolerated and responded well to the therapy, with an overall response rate of 62%.

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