Cancer is one of the most complicated, formidable challenges in medical science. Although the oldest report of “cancer” was in Egypt back in 3000 BC, it continues to affect millions of lives worldwide. In 2022 alone, there were over 20 million new cancer diagnoses and nearly 10 million cancer deaths around the world.
Despite the improvements and breakthroughs in cancer research and treatment, the quest for a cure remains elusive. However, vaccines are one of the innovative approaches gaining traction in recent years. These cancer vaccines are a promising frontier in oncology, designed to either prevent cancer or treat existing cases by “retraining” the body’s immune system.
The concept of using vaccines to combat cancer is not entirely new. Prophylactic vaccines, such as those against the Human Papillomavirus (HPV) and Hepatitis B, have already demonstrated efficacy in preventing virus-induced cancers. Ongoing developments have recently opened new avenues for transforming cancer treatment.
Quick Recap of Cancer Vaccines: What Are They?
Cancer vaccines are a form of immunotherapy. We discussed the common types in our previous article, including the prophylactic vaccines that help prevent cancer by targeting cancer-causing viruses like Human Papillomavirus (HPV) and Hepatitis.
Therapeutic vaccines are another type that treat existing malignancies by boosting the immune response against cancer cells. One example is Provenge (Sipuleucel-T), an FDA-approved drug for the treatment of metastatic prostate cancer. More therapeutic vaccines are now under development, targeting various cancers by stimulating the immune system to attack malignant cells.
What Are the Recent Advances in Cancer Vaccines?
The scientific and medical communities have excelled in understanding and developing cancer vaccines in recent years. Among the most promising progressions include:
1. Personalized Vaccines for Cancer Immunotherapy
In a study, tailoring vaccines based on each patient’s tumor profile demonstrated that targeting individual tumor mutations is feasible, safe, and effective in boosting the immune response. These vaccines contain specific antigens found in a patient’s tumor, making the immune response more precise and effective.
2. mRNA Vaccine for Glioblastoma
Leveraging the success of mRNA technology in COVID-19 vaccines, scientists are now exploring mRNA vaccines for cancer. In particular, researchers from the University of Florida developed a promising new mRNA cancer vaccine in early 2024. In the study, researchers used the participants’ tumor cells to produce a personalized vaccine for glioblastoma, the most common malignant brain tumor.
The vaccine instructs cells to produce cancer-specific antigens, thereby training the immune system to attack tumors.
“Our brain tumor program has developed promising effects with other forms of immunotherapy against brain cancer and wanted to test a novel mRNA vaccine design to enhance responses for these difficult-to-treat diseases,” said lead author Elias Sayour, MD, PhD, in an interview with Medical News Today.
Impressive Results in Animal Participants
In the study, Sayour and his fellow researchers used the individual tumor cells of participants to create personalized mRNA vaccines for their specific diagnosis. This approach aimed to elicit a robust and targeted immune response against the patient’s unique cancer profile. They studied the efficacy of these personalized mRNA cancer vaccines by enrolling ten dogs with naturally occurring brain tumors, as their owners had exhausted other treatment options. The results were promising, as the dogs treated with the mRNA cancer vaccine exhibited an average survival rate of 139 days, significantly exceeding the typical 30- to 60-day survival rate for dogs with this condition.
Promising Results in Human Participants
Motivated by the promising animal study, the researchers expanded their investigation to a small FDA-approved clinical trial involving four human participants with glioblastoma. Within 48 hours of receiving the mRNA vaccine, the researchers observed a remarkable shift in the tumor’s immune response. The tumor changed from a “cold” (suppressed) state to a “hot” (active) state, indicating the vaccine’s potential to stimulate a robust and targeted immune response against brain tumors.
3. mRNA Vaccine for Pancreatic Cancer
Pancreatic ductal adenocarcinoma (PDAC) is a common type of pancreatic cancer with a high mortality rate, with about 95% of patients dying from the disease. Immunotherapies have been groundbreaking for many cancers but have not been effective for PDAC, mainly due to uncertainties about whether PDAC cells produce neoantigens that the immune system can target.
In 2023, Dr. Vinod Balachandran and his research team at Memorial Sloan Kettering Cancer Center developed a personalized mRNA cancer-treatment vaccine. This breakthrough vaccine helps immune cells recognize specific neoantigens in pancreatic cancer cells. In the clinical trial, the researchers sent tumor samples from 19 patients to BioNTech for gene sequencing. They had hoped to identify potential neoantigens, resulting in customized mRNA vaccines for 18 participants. The process took about nine weeks, from surgery to the first vaccine dose.
Encouraging Results in Human Patients with Strong Immune Responses
Participants received an immune checkpoint inhibitor before vaccination, followed by nine vaccine doses and standard chemotherapy. Half of the patients developed strong T-cell responses to their vaccines, and these patients did not see their cancer return within a year and a half. In contrast, cancer recurred in patients without strong immune responses. These promising results suggest that personalized mRNA vaccines could target PDAC and potentially other cancers. Further research and larger clinical trials are in the planning phase.
How Do mRNA Vaccines Work for Cancer?
Messenger ribonucleic acid (mRNA) vaccines for cancer are a major advancement in precision oncology. They translate the information encoded in our genetic blueprint into the proteins that define our unique biological characteristics, including those that contribute to cancer development. By harnessing the unique mRNA profiles of an individual patient’s cancer, it is now possible to engineer personalized vaccine therapies that target the specific molecular features of that person’s tumor.
Dozens of other clinical trials are testing mRNA treatment vaccines in cancer patients, including those with colorectal cancer and melanoma. Some vaccines are already under evaluation in combination with precision medicine.
As medical and scientific researchers continue to make strides in understanding and developing cancer vaccines, there is renewed hope and cautious optimism about their potential to treat and, perhaps one day, cure various forms of cancer.
