When treating melanoma, the deadliest form of skin cancer, doctors usually first remove as many cancer cells as possible through surgery. They may then give another treatment, such as chemotherapy or radiation, to kill the missed cancer cells. Certain types of melanoma are considered to be at high risk of recurrence, including particularly thick melanoma or melanoma that has metastasized (spread to other parts of the body) before treatment.
Adding a cancer vaccine being developed by Moderna to standard treatment for melanoma could significantly reduce the risk of death or recurrence in cancer survivors, according to newly shared trial data.
Cancer vaccine company Moderna and pharmaceutical giant Merck are developing an mRNA-based cancer vaccine, mRNA-4157 (V940), for patients who have had high-risk melanoma removed. The vaccine works by instructing the body to make up to 34 "neoantigens." These proteins are found only in cancer cells, and Moderna provides each recipient with a personalized vaccine that carries instructions for the cancer cell neoantigens.
The idea behind the vaccine is that by prompting the body to make these proteins, it prepares the immune system to quickly recognize and attack any new cancer cells that carry these proteins, thereby preventing recurrence.
In the ongoing phase 9422b study of KEYNOTE-9422, Moderna and Merck are comparing the cancer vaccine's ability to prevent recurrence or death from melanoma when used in combination with Merck's FDA-approved cancer treatment Keytruda versus Keytruda alone.
In 2022, they reported that the combination reduced high-risk patients' risk of relapse or death by 44% compared with Keytruda alone within two years of treatment.
Now they've announced that patients who received both therapies had a 49% lower risk of relapse or death at a median three years after treatment compared with those who received Keytruda alone. They were also 62% less likely to develop distant metastasis or die.
Moderna President Stephen Hoge told Reuters: "The durability of these responses is very strong - they are basically rock solid during this time, which is a considerable improvement compared to the standard treatment with Keytruda alone. We believe that in some countries, this product can be marketed through accelerated approval before 2025."
However, the KEYNOTE-942 study is relatively small, with only 157 participants, but Moderna and Merck have launched a Phase 3 trial of the cancer combination therapy that will involve more than 1,000 patients with high-risk melanoma.
The two companies are also looking beyond melanoma, launching a Phase 3 trial to test the cancer vaccine in patients with non-small cell lung cancer - and if these trials go well, it may not be long before patients can enjoy such personalized treatments.
"We believe that in some countries the product could be available through accelerated approval before 2025," Moderna CEO Stephane Bancel told AFP.