Vaccine fails to improve outcomes of stage 2 melanoma

An attempt to positively affect stage 2 melanomas with a certain vaccine didn’t prove beneficial in a recent study by the European Organization for Research and Treatment of Cancer (EORTC).

In the study, 657 patients with stage 2 melanomas thicker than 1.5 mm were vaccinated with GM2-KLH-QS21, and an observation group had another 657 patients with stage 2 melanomas who did not receive vaccinations, according to a news release.

The idea behind the study was to target an antigen in many melanomas - GM2 ganglioside - with the vaccine, which stimulates the production of antibodies to the GM2 ganglioside, according to the release.

“Serological response to GM2 was shown to be a positive prognostic factor in patients with melanoma and was the rationale for this trial,” the release stated.

During the study, patients who received the treatment were vaccinated by subcutaneous injections once a week during the first month, then once every three months during the first two years, and then once every six months during the third year, according to the news release.

“These results clearly indicate that we do not fully comprehend the impact, on the whole, of multiple vaccinations,” said Alexander M.M. Eggermont, M.D., Ph.D., coordinator of the study. “The effects of such vaccinations might well be detrimental as was clear at the time of the interim analysis that stopped this trial. Now that we have entered a new era in immunotherapy in melanoma with checkpoint inhibitors like anti-CTLA4, and especially with anti-PD1/PDL1, a new opportunity for vaccine development may have arrived.”

The trial was stopped for futility at a median follow-up of 1.8 years, according to the release.

The findings were published in the Journal of Clinical Oncology.