The covid-19 pandemic has put mRNA vaccines in the spotlight. But this technology can also be a powerful weapon in the fight against more aggressive cancers.
by Stacey ColinoPublished Jul 15 2021 07:00 BRTMalignant Melanoma
Malignant melanoma (in pink) is one of the most feared types of cancer in humans. From its place of origin, propagation is rapid and can reach virtually any organ, such as the lung, shown in this photo. In this image, the colors do not represent the actual pigmentation of the cells.Photo by Image by Dr. Cecil H. Fox, Science Source
In February 2019, Molly Cassidy was studying for the Arizona State Bar exam when she felt a terrible pain in her ear. Pain eventually radiated to her jaw, prompting her to discover a lump under her tongue.
“Several doctors told me that the cause could be stress, because I was studying for the bar exam and I had a 10-month-old son”, recalls Cassidy, who is also a PhD in Education. She continued to seek other medical opinions and found that she had an aggressive form of head and neck cancer that required intensive treatment.
After doctors removed part of her tongue and 35 lymph nodes, Cassidy had 35 sessions of radiation therapy, simultaneously with three cycles of chemotherapy. Ten days after the treatment ended, Cassidy noticed a marble-like lump on her collarbone. The cancer had returned—and in full force:
it had spread through her neck and into her lungs. “At that point I really had no options because the other treatments hadn’t worked,” recalls Cassidy, who lives in Tucson and is now 38 years old. “In the middle of 2019, I was told that my cancer was very serious and that I should get my life in order. I even planned my funeral.”
When the collarbone tumor was removed, doctors said she might be a good candidate to participate in a clinical trial at the University of Arizona Cancer Treatment Center to test the use of an mRNA (messenger ribonucleic acid) vaccine — technology similar to that used in the covid-19 vaccines developed by Pfizer and Moderna
— in conjunction with an immunotherapy drug used to treat colorectal and head and neck cancers. While covid-19 vaccines are preventative, mRNA vaccines for the treatment of cancer are therapeutic, and Cassidy took the opportunity to participate in the trial. “I was in the right time and place to participate in the clinical trial,” she says.
When people started hearing about the covid-19 vaccines developed by Pfizer-BioNTech and Moderna, the mRNA technology behind them seemed like science fiction. But while the mRNA approach seems revolutionary, researchers began developing vaccines using mRNA long before the advent of covid-19, to fight cancer and autoimmune diseases like multiple sclerosis, and to protect against infectious diseases like respiratory syncytial virus.
“It’s not a new idea: what covid-19 has shown us is that mRNA vaccines can be an effective and safe technology for millions of people,” says Daniel Anderson, head of nanotherapy and biomaterials at the Instituto de Tecnologia de Massachusetts and member of the Koch Institute for Integrative Cancer Research.
Currently, phase one and two clinical trials are either recruiting participants or evaluating the efficacy, tolerability, and safety of therapeutic mRNA vaccines to treat various forms of cancer. Types include melanoma, non-small cell lung cancer, gastrointestinal cancer, breast, ovarian and pancreas cancer, among others.
“One of the advantages of this technology is that it can be used on people whose cancer has not been identified — it doesn’t matter if the cancer is breast or lung, as long as you can identify their mutations,” explains Van Morris, MD and assistant professor of gastrointestinal medical oncology at the University of Texas MD Anderson Cancer Center in Houston, leader of a phase two clinical trial exploring the use of personalized mRNA vaccines for patients with stage two or three colorectal cancer. “One of the most interesting aspects is the adaptability of the technology to a particular type of cancer and its underlying biology.”
Over the course of 27 weeks, Cassidy received nine doses of a personalized mRNA vaccine, along with intravenous infusions of an immunotherapy drug called Pembrolizumab. Her doctor, Julie E. Bauman, deputy director of the University of Arizona Cancer Center, examined her weekly, and then every three weeks; Cassidy also had CT scans regularly. After each injection, Cassidy suffered a peak of fever and felt exhausted—with fatigue and body aches—for 24 hours. “My immune system worked in a way