New developments in cancer research suggest that treatment vaccines may be the key to eliminating certain types of cancer. Unlike preventive vaccines like HPV that have been around for years, treatment vaccines teach the body to attack live cancer cells. Patients who participated in studies on these personalized vaccinations showed significant signs of remission.
Cancer Prevention Vaccines Using HPV
There are vaccines that help people maintain their health and keep cancers from developing the same way vaccines for chicken pox or flu protects the body from virus-causing diseases. According to the FDA, there are two types of cancer prevention vaccines. The first one is the HPV vaccine, which protects against human papillomavirus. This virus may cause certain types of cancer if not treated, such as cervical and vaginal cancers, among others. The other vaccine is the hepatitis B vaccine. If untreated, hepatitis B can cause liver cancer.
Cancer Treatment Vaccines
Patients diagnosed with cancer are the ones who receive treatment vaccines. These vaccines help boost the patient’s immune system to destroy cancer cells, stop tumors from growing, spreading, or coming back.
Antigens are toxins that are not normally found in the body and appear on the surface of cancer cells. The vaccines attack these antigens, and leave a memory system that recognizes and fights antigens that may form in the future.
Many cancer treatment vaccines are only available for clinical trial volunteers. But in 2010, the FDA approved Provenge, a cell-based cancer immunotherapy for men with metastatic prostate cancer. Each patient received customized treatments. First, white blood cells, the cells that fight diseases and infections, are extracted from the blood. Next, researchers modify the white blood cells in the laboratory so they can target prostate cancer cells. The modified cells then return to the body intravenously, much like a blood transfusion. These modified cells train the immune system to recognize and fight off the cancer cells.
A Stanford University of Medicine study determined that injecting tumors with similar agents trigger the immune system in mice. Researchers will begin testing with about 35 human subjects with lymphoma later in the year. In the research with mice, the test subjects had various cancers—lymphoma, breast, and colon cancer. The treatment eliminated cancer tumors in 87 of 90 mice, even when the tumors had metastasized.
Another recent study published in JAMA Dermatology involved two senior patients who had skin cancer growths previously removed. The study built on the investigation that HPV infections play a role in the development of certain skin cancer types. Extracted parts of the cancer cells mixed with agents triggered a positive response in their immune system. Consequently, the vaccine diminished the formation of basal and squamous cell carcinomas, the two most common skin cancers.
A similar study at Boston’s Dana-Farber Cancer Institute took tumor samples from six patients with melanoma. These patients’ tumors were previously removed but they still had a high risk for recurrence. Researchers used algorithms to determine which specific antigens would stimulate a specific patient’s T cells. Patients were injected with synthesized antigens. In the first trial, four of the six patients exhibited no recurrence of the cancer more than two years after the vaccination. The two that had recurrence had a second round of treatment and also went into remission.
Another trial by Germany’s Biopharmaceutical New Technologies (BioNTech) used the same strategy for 13 patients with melanoma. The vaccines targeted up to 10 antigens in each patient, and 8 of the 13 were cancer-free after 23 months.
The time and costs it takes to develop these HPV vaccines are two of the biggest challenges in these clinical trials.
Currently, it totals to at least $60,000 to produce one patient’s neoantigen vaccine. This total could also hike up in tandem with other drug innovations. The studies noted that it took months to produce the vaccines, and even years to see changes in the patient’s cancer development.
Apart from the time and money factors of research, there are other challenges with patients. One, cancer cells suppress the immune system, meaning weaker or older people’s bodies may not be able to produce strong responses to vaccinations. Two, some cancer cells disguise themselves as healthy cells, so vaccines sometimes do not recognize them. And third, larger or advanced tumors are difficult to eliminate using just vaccine. Sometimes doctors give patients accompanying treatments for a better chance of eliminating cancers.
Clinical trials are crucial in exploring how vaccines can be further used to treat different types of cancers. Currently, there are trials that use similar methods to treat bladder, cervix, breast, cervical, brain, lung, kidney, prostate cancers, and many others.
Alternatively, there are other methods of detecting skin cancer, like handheld sensors, but solutions like this are still not as readily available in the market. There is also a need for public and private institutions to support these initiatives so researchers can include a larger number of test subjects. With backing from these institutions, scientists can better determine the direct link between vaccines and eliminating cancers. Eventually, drugs could also soon be accessible to help the wider public heal and recover from a life-threatening disease.