When will the world have a cancer vaccine?

Unlike traditional vaccines that prevent disease, personalized cancer vaccines are created for use in people who already have cancer.

As cancer continues to vary greatly in both its characteristics and course from person to person, researchers are focusing on tailoring treatments for each individual. One notable advance is the emergence of personalized cancer vaccines, designed specifically for each patient's unique pathology.

What is a personalized cancer vaccine?

Unlike traditional vaccines that prevent infections, personalized cancer vaccines, also known as neoantigen vaccines, are used in people who have already been diagnosed with cancer.

Cancer vaccines work by targeting proteins on tumors called neoantigens. (Illustration: Nature).

The vaccine works by targeting proteins on the tumor called neoantigens . These proteins are only present in cancer cells, are the result of genetic mutations, and are unique to a particular patient.

Scientists rely on genome sequencing, a process that examines human cellular components like DNA and RNA that undergo changes when someone develops cancer, according to Very Well Health. This analysis allows researchers to use a portion of a tumor or a blood sample to get information about the underlying biological processes that cause cancer.

The vaccine was designed to target damaged cells while avoiding damaging healthy cells — a common problem with traditional cancer treatments like chemotherapy and radiation.

Advances in sequencing mean that it now takes weeks to create a vaccine, rather than months, said Dr. Toni Choueiri, an oncologist at the Dana-Farber Cancer Institute in Boston. Sequencing costs are also falling, which will make it easier to produce vaccines on a large scale, he said.

Advantages and disadvantages

Personalized cancer vaccines are all designed to deliver a customized treatment, but not all of them operate on the same platform.

Personalized vaccines will be a major step forward for humanity in finding and treating today's most dangerous diseases. (Photo: Medpagetoday).

Some vaccines are protein-based, such as peptide or epitope-based vaccines, while others are cell-based, virus-based, or RNA-based. Each type of vaccine platform has its pros and cons, according to Choueiri:

• Cell-based vaccines are highly effective at generating immune system responses but are expensive and difficult to produce.
• Protein and peptide-based vaccines are easier to produce and have low toxicity but are quite expensive.
• Virus-based vaccines are simple to produce but have the potential to leave patients vulnerable to infection.
• RNA-based vaccines make it easier to deliver a variety of antigens, but they may elicit less of an immune response. They also require special cold storage.

While personalized vaccines are a promising development in treating patients with many different types of cancer, it is important to note that they will not replace traditional cancer treatments.

Which vaccines have been approved?

Currently, the only personalized cancer vaccine approved by the US Food and Drug Administration (FDA) for use in this country is Provenge (sipuleucel-T). The vaccine is intended for patients with metastatic prostate cancer who have few symptoms and whose cancer has not responded to testosterone-lowering therapies.

Still, the outlook looks promising for future FDA approval of personalized cancer vaccines. Here are the vaccine candidates currently in testing:

Malignant tumor

• V940: The personalized neoantigen vaccine V940 (also known as mRNA-4157) was tested in combination with the targeted therapy pembrolizumab in patients with completely resected high-risk stage IIIB/IV melanoma.
• EVX-01: Peptide-based vaccine EVX-01 plus targeted therapy drug pembrolizumab shows promise for people with metastatic melanoma.
• EVX-02: In people with completely resected melanoma but at high risk of recurrence, the DNA-based vaccine EVX-02 combined with the immunotherapy drug nivolumab produced a sustained T-cell response and relapse-free survival at 12 months.

Pancreatic cancer

• Autogene cevumeran: This mRNA vaccine, currently in phase 2 trials, offers hope to people with pancreatic cancer.

Non-small cell lung cancer

• Tedopi: Positive results in phase 3 trial evaluating it against chemotherapy in patients with HLA-A2 biomarkers with non-small cell lung cancer.

Ovarian cancer

• UPCC 19809 and UPCC 29810: These two ovarian cancer vaccines are in phase 1 and 2 trials, both using proteins obtained from patients' tumor cells.

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