Using mRNA technology in vaccines to fight cancer

Until recently, most of the world had never heard of mRNA vaccines. To combat COVID-19, the United States Food and Drug Administration issued emergency use authorization in December 2020 for mRNA vaccines developed by Pfizer-BioNTech and Moderna.

While the pandemic brought mRNA vaccines into the limelight, melanoma patient Bobby Fentress had experience with mRNA technology nearly a year prior.

mRNA vaccines hold promise for fighting infectious diseases beyond the SARS-CoV-2 virus, including fighting cancer. At age 68, Bobby was an early participant in a clinical trial intended to see whether a vaccine made with mRNA could destroy his cancer cells and prevent recurrence.

Bobby’s story began in 2019. He found an odd bump on his middle finger and assumed it was a wart. After his wife urged him to be seen by a dermatologist, he received a call that he would need a biopsy – which ultimately revealed that he had stage 2c melanoma. Several months later, Bobby had most of his middle finger amputated and was told that there was a 50% possibility that the cancer would reoccur.  

That’s when Bobby decided to enroll in a clinical trial with HCA Healthcare’s Sarah Cannon Research Institute in Nashville, Tennessee.

He received his first shots of a personalized mRNA vaccine created by Moderna in April 2020. These vaccines are developed from a patient’s specific tumor DNA. The DNA of the tumor is analyzed to determine the differences between the tumor and a patient’s own cells and which proteins might elicit the best immune response. The mRNA vaccine is then developed to instruct the body to make these proteins and stimulate an immune response. Patients such as Bobby then receive a series of these vaccine treatments.

Bobby finished his year of treatment earlier this spring. While it is too early to know if the therapy will work, Bobby’s oncologist, Dr. Meredith McKean, is optimistic.

We sat down with Dr. McKean, associate director of the melanoma and skin cancer research program at Sarah Cannon Research Institute, to discuss mRNA vaccine technology and how it’s being researched for cancer treatment:

What is mRNA?

Dr. McKean: Messenger RNA vaccines (mRNA vaccines) instruct our body to make a protein specific to cancer, so our body has been exposed and recognizes it as a protein foreign to our body. This triggers a short-term immune response that patients may notice as fever or chills and also trains the body’s memory cells to produce antibodies to this protein. This develops both a short and long-term immune response.

How is mRNA technology being used in cancer treatment?

Dr. McKean: mRNA technology is being used to give a personalized and targeted approach to cancer treatment. Once a tumor has been removed from a patient, it’s sent off to create a unique vaccine. A computer analyzes differences in a patient’s normal cells and cancer cells, and a vaccine is developed to trigger the body to make the proteins found in the patient’s cancer cells. Once the patient receives the vaccine, their immune system works to fight anything with that protein – which in this case is the cancer.

How are cancer patients deemed good candidates for mRNA therapy?

Dr. McKean: This is a great option for patients we know are high risk – particularly those battling melanoma. It’s ideal because these patients have already completed surgery, so we can send off the tumor while they are recovering to develop the vaccine. Then we can offer treatment in conjunction with immunotherapy – a type of biological therapy that is considered standard of care in melanoma to stimulate the immune system in response to cancer.  

Are there any side effects associated with using mRNA technology as a treatment option?

Dr. McKean: The side effect profile and data presented have shown that side effects from this treatment are similar to what we see with immune checkpoint inhibitors and the COVID-19 mRNA vaccine. Side effects include acute symptoms for 24 hours such as fever, chills, and rigors and long-term side effects related to immune stimulation of different organs such as skin, liver, lungs or kidney that generally resolve with steroids.

What does the hope of this treatment option mean for cancer patients and clinicians?  

Dr. McKean: Immunotherapy has been a game changer for melanoma. With mRNA, the hope is that personalized therapy would offer additional treatment benefit above our standard treatments that we offer for patients broadly. Even for patients like Bobby that had surgery, ten years ago we wouldn’t be able to give him anything but highly toxic therapy options. It’s refreshing to offer a clinical trial like this. While the trial is not yet complete, we have enough data to be hopeful. It’s a very encouraging area that I’m excited about as a provider.

I also think it’s been really exciting for our colleagues and patients to feel like they’re contributing to something bigger. It’s been very satisfying to see our work in cancer researsch lay the groundwork for the COVID-19 mRNA vaccine; I’m really proud of our mission and our patients. Our patients join clinical trials for their own potential benefit, but also to benefit future cancer patients by hopefully giving them better treatment options. Cancer patients are very giving, and this has been just another example of that.

Read more about Bobby’s story and how mRNA technology is being used to treat cancer on USA Today and watch Dr. McKean’s recent appearance on NBCLX: