Moderna and Merck announced Tuesday morning that a combination of an investigational personalized mRNA cancer vaccine and Keytruda showed efficacy in patients with Stage III/IV melanoma. 

The Phase 2b trial found the combination of mRNA-4157/V940 and Keytruda delivered “a statistically significant and clinically meaningful improvement” in the primary endpoint of recurrence-free survival for patients with stage III/IV melanoma compared to Keytruda alone. The joint treatment also reduced the risk of recurrence or death by 44% compared to Keytruda alone.

Melanoma is a common cancer in the U.S., with nearly 100,000 new diagnoses each year and resulting in more than 7,600 deaths, according to data from the American Cancer Society. 

Moderna CEO Stéphane Bancel said the results are “highly encouraging for the field of cancer treatment” and demonstrated the “potential for mRNA to have an impact on outcomes in a randomized clinical trial in melanoma.”

In an appearance on Squawk Box Tuesday morning, Bancel added that, “If we are able to teach the T cells of a cancer patient to recognize the mutation of that specific cancer that it could not recognize before, that’s a massive medical step forward.”

Merck Research Laboratories President Dr. Dean Y. Li said the results represent “an important milestone in our collaboration with Moderna” and that the company looks forward to “advancing this program into the next phase of development.”

The companies said they plan to discuss the results with regulatory authorities and then initiate a Phase 3 study in melanoma patients in 2023. 

Additionally, Merck has already exercised its option to jointly develop and commercialize mRNA-4157/V940, meaning the two companies will share costs and profits equally going forward. 

Even before the trial results were released, Keytruda was a high performer for Merck. According to its latest earnings report, the drug used to treat lung cancer saw sales grow by 20% year-over-year to $5.4 billion.

The news was also released one day after Merck launched its $1.35 billion tender offer for Imago BioSciences.

For Moderna, mRNA continues to drive the pharma company’s prospects forward. After developing an effective, bivalent COVID-19 vaccine, Moderna has doubled down on mRNA technology for use in treating other diseases like cancer. 

The company has also been protective of its mRNA technology, even suing Pfizer and BioNTech over the summer, alleging the two companies copied the patented technology for their COVID-19 vaccine.