Cancer Vaccine
Moderna and Merck Co. are pioneering the research and development of a Cancer Vaccine
A personalized messenger RNA (mRNA) cancer vaccine developed by Moderna and Merck Co. has indicated positive results in a randomized Phase 2 clinical trial. The shot, combined using Merck’s checkpoint inhibitor Keytruda, reduced cancer recurrence risk or death by 44 percent compared to Keytruda over one year. According to Moderna’s program director for oncology, Michelle Brown, during the 14 Dec 2022 roundtable with reporters, "The vaccine was tested in persons with stage 3/4 melanoma who had their tumors removed but with a greater chance of cancer return because of their melanoma features."
Merck and Moderna said they're the first firms to show efficacy in a randomized clinical trial for mRNA-based cancer treatment. Brown said in the roundtable, “This profound clinical benefit for patients really substantiates the idea of a personalized cancer vaccine. And it also really gives us confidence in the potential for mRNA in oncology patients.”
The vaccine is personalized
The Moderna/Merck vaccine is personalized. What does this mean? It shows that the mRNA sequences it delivers are customized or tailored to each patient while being aimed at preventing cancer recurrence instead of preventing cancer. The mRNA encodes tumor-specific mutations known as neoantigens. The body will create neoantigens copies, learn how to recognize them, and finally makes more immune cells to target them so they will fight cancer.
The cancer vaccine possibility has been met with some excitement. For Gritstone’s Allen, “Up to this point, obviously we didn’t know that cancer vaccines could work. Essentially they have repeatedly failed for many years. And specifically, we didn’t know that they could work to augment the effects of checkpoint inhibitors. And both of those elements appear to have been proven now.”
Allen knows that Merck and Moderna haven't released the trial full data. However, he said, “if we assume that what’s been reported publicly bears up to further scrutiny, then this is an important milestone for the field, obviously, and for us as a company.”
It's good to add that the Moderna-Merck cancer vaccine was only tested in melanoma patients, and melanoma isn't typical. It has high immunogenicity. This means it can naturally elicit a strong immune response in the body, which can hamper tumor progression, particularly if the response is helped by activators such as checkpoint inhibitors. According to Allen, other cancer types spark a less powerful natural immune response.
Allen added, “The successes of melanoma don’t effortlessly translate into the more common solid tumors, like lung, colon, prostate, breast, and ovary, which are the big five.” In fact, melanoma is distinct from other cancers and has served as a proving foundation for immunooncology agents. However, for Brown, because agents are successful there, it doesn’t preclude them from being successful in other tumor types.
Phase 3 study is underway in 2023
Overall, the Moderna/Merck cancer vaccine has shown promise in trials. This comes as the two companies plan to start a Phase 3 study and trial in melanoma people in 2023.
