Moderna, Merck say vaccine improved survival in patients with deadly skin cancer

Moderna and Merck released more positive three-year data Monday on their experimental vaccine, given to patients with the most deadly form of skin cancer in combination with the therapy Keytruda.

The vaccine together with Merck's Keytruda improved survival and showed long-lasting efficacyin a midstage study in patients with a deadly form of skin cancer. Moderna and Merck are presenting the data at the American Society of Clinical Oncology annual meeting in Chicago.

The shot is a key part of Moderna's pipeline that has helped shore up investor sentiment for the biotech company following a rocky last year, when demand plummeted for its Covid vaccine, for now its only commercially available product.

The data includes the initial results the two companies announced in December.

Among new data, nearly 75% of patients who took the combination were alive without any signs or symptoms of their cancer returning at the 2½-year mark. That compares with 55.6% of patients who got Keytruda alone. 

That benefit was observed across different subgroups of patients, regardless of whether they had tumors with a large number of mutations or whether they had enough of a protein — called PD-L1 — that helps keep the body's immune responses in check. 

The data reflects the potential for the shot to help treat a "broad range" of melanoma patients, Dr. Kyle Holen, Moderna's head of development, therapeutics and oncology, said in a release.

The overall survival rate of patients who took the vaccine in combination with Keytruda was 96% after 2½ years. That compares with 90.2% among those who took Keytruda alone.

"As we look at the three-year updates, what's really exciting to me seeing the durability of that data," Marjorie Green, Merck's head of global