Preliminary But Encouraging Results: ‘Personalized’ mRNA Vaccine Trial Targets Advanced Skin Cancer

The biotech company Moderna has announced preliminary -- but significant -- progress in a clinical trial of its “personalized” cancer-vaccine program aimed at preventing the return of serious cases of melanoma, a common type of skin cancer, in patients who initially had surgery to remove their cancer.

Michael J. Zinner, M.D., CEO and executive medical director for Miami Cancer Institute.

The clinical trial, which also involves the drugmaker Merck, uses Moderna’s messenger RNA (mRNA) technology, which was the prominent system behind the vaccines against COVID-19 manufactured by Pfizer-BioNTEch and Moderna. In trial targeting skin cancer, the mRNA is designed to stimulate an immune response by generating specific T-cell responses in the patient based on the “unique mutational signature” of a patient's tumor, Moderna said.

"While these results are preliminary, the trial's findings thus far are very encouraging," said Michael J. Zinner, M.D., CEO and executive medical director of Baptist Health Miami Cancer Institute. "We knew that mRNA vaccines are evolving as major players in precision medicine for fighting diseases, including cancer. Similar to how theses vaccines flagged a person’s immune system to COVID-19’s spike protein, therapeutic mRNA-based vaccines may be able to warn about a present cancer so the immune system can destroy the tumor cells."

The 157 patients who took part in the second phase of the Moderna-Merck trial had surgery to remove their melanoma cancer, and then received treatment with either just Merck's cancer drug Keytruda, or Keytruda and Moderna's vaccine. Moderna designed each vaccine to the unique DNA of each person's tumor through a mostly automated laboratory process. The group that got Moderna's vaccine had a 44 percent reduction in the rate of cancer recurrence and death, compared to the trial participants who just got Keytruda.

The preliminary results of this phase in the clinical trial were shared in a news release by Moderna and Merck, but the findings have not been peer-reviewed or published. These are two important steps before more studies are conducted to determine the effectiveness of mRNA technology in fighting cancer. The companies said they will publish the full data in the future and share results at an upcoming conference.

Guilherme Rabinowits, M.D., hematologist and medical oncologist at Miami Cancer Institute.

 

Guilherme Rabinowits, M.D., is a hematologist and medical oncologist at Miami Cancer Institute. Dr. Rabinowits, who specializes in treating head and neck cancers -- and melanoma and non-melanoma skin cancers – said he is not surprised that the first major clinical trial using mRNA vaccines are targeting the recurrence of melanoma skin cancer cases.  Many studies have indicated that TILs (tumor-infiltrating lymphocytes) are a favorable prognostic factor for melanoma patients. Lymphocytes are a type of immune cell that has moved from the blood into a tumor.

“Melanoma is a highly immunogenic tumor with one of highest tumor mutation burden, and a microenvironment that is highly infiltrated by lymphocytes,” explains Dr. Rabinowits. “It is indeed a great tumor choice to investigate the use of a cancer vaccine to enhance cell-mediated immunity.”

Melanoma is potentially the most serious form of skin cancer because of its ability to spread to other organs more rapidly. It begins in the cells known as melanocytes that are found in the deepest part of skin cells. While it is less common than basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), melanoma is more dangerous.

“Melanoma’s high tumor mutation burden leads to a large number of tumor specific antigens to choose from for the vaccine formulation,” adds Dr. Rabinowits.

Stéphane Bancel, Moderna's chief executive officer, said in a statement: "We will begin additional studies in melanoma and other forms of cancer with the goal of bringing truly individualized cancer treatments to patients. We look forward to publishing the full data set and sharing the results at an upcoming oncology medical conference, as well as with health authorities."

Dr. Zinner wrote about the prospect of mRNA technology in fighting cancer in January of this year in the article: The Promise of Precision Medicine Means Hope for Cancer Patients.