A trial demonstrates that the combination of immunotherapy and an experimental cancer vaccine is still effective against melanoma.

According to the drugmakers, an experimental mRNA vaccine combined with immunotherapy is still beneficial for patients with high-risk melanoma skin cancer. This information was released on Thursday.

Those who received the vaccine from Moderna and Merck in addition to Merck’s Keytruda immunotherapy had a 49% lower risk of recurrence or death and a 62% lower risk of distant tumor cell spread or death compared with those who received Keytruda alone, according to a news release from the companies. The trial participants had undergone a full removal of stage III or IV melanoma but were at high risk of the cancer returning.

Individuals who received both Keytruda and the mRNA-4157/V940 vaccine had a 44% lower risk of recurrence or death and a 65% lower risk of distant metastasis or death when compared to those who received Keytruda alone, according to a two-year follow-up.

Stephane Bancel, the CEO of Moderna, told CNN on Thursday that the company is constructing a new commercial manufacturing facility in Massachusetts in order to be ready for a possible accelerated approval of the customized therapy as early as 2025.

In 2014 the US Food and Drug Administration approved Keytruda for the treatment of specific cancers. Keytruda increases the immune system’s capacity to identify and combat cancer cells. The combination of mRNA-4157/V940 and Keytruda has been given a breakthrough therapy designation by the agency. This designation speeds up the development and review process for medications meant to treat serious conditions and that, based on preliminary clinical evidence, may represent a significant improvement over currently available therapies.

Approximately 25% of trial participants who received both Keytruda and the vaccine reported serious side effects associated with the treatment, compared to approximately 20% of those who received Keytruda alone. The three most frequent adverse effects linked to the vaccine were chills, injection site pain, and exhaustion.

There has been no peer review or publication of the Phase 2b trial data in a scholarly journal. Phase 3 trials for stage IIB-IV melanoma and non-small-cell lung cancer have reportedly started at Moderna and Merck, and the companies intend to broaden the scope of the study to encompass additional tumor types.

Melanoma makes up roughly 1% of all skin cancer cases, but most skin cancer deaths are caused by this disease, according to the American Cancer Society. According to their estimates, approximately 8,000 people would lose their lives to melanoma and 100,000 new cases of melanomas would be diagnosed in the US in 2023.