CANCER VACCINES

2. How do they work?

• Traditionally, vaccines inject part or all of a weakened virus (or other pathogens) into the body to provoke an immune response.
• mRNA works by injecting only the genetic instructions and allowing the body's cells to make part of the cancer protein (Antigen) itself. This trains the immune system to develop antibodies against the protein.
• When these same proteins are present on an invading tumour cell, the immune system stimulates an immune response against it.
• While COVID mRNA vaccines respond to one antigen- the spike protein on the outside of coronavirus- cancer vaccines act on several antigens present on the tumour surface.
• The mRNA cancer vaccines train the patient's immune system to fight their cancer.
• Most trials are manufacturing vaccines for individual patients based on the specific antigens present in their tumours. It takes around two months to produce a vaccine.

3. How these vaccines are made?

• To make these vaccines, a sample of the patient's tumour and healthy tissue is taken.
• These samples are DNA-Sequenced to compare differences between the DNA in the cancerous cells and the healthy cells.
• Scientists identify problem mutations driving the disease. These can then be used as antigen targets in the mRNA vaccine.
• Bespoke approaches allow scientists to target a wider range of cancer antigens. Targeting multiple antigens decreased the odds that cancer cells will mutate and become resistant to vaccines because the immune system attacks on multiple fronts.
• Personalised medicines are extremely expensive because they are bespoke products.
• Manufacturing costs for bespoke treatments remain high.
• However, with rapidly falling costs of different aspects such as genome sequencing (Some companies are now offering genome sequencing for just US$100), sequencing the entire genome is becoming more viable.
• As large-scale manufacturing increases in future for off-the-shelf vaccines, there will be resource efficiencies that reduce cost.

Image Source: Moderna, CDC, FT

4. What are the vaccines that are in development?

• In December 2022, Moderna and Merck (known outside the United States and Canada as MSD) published the results of its early phase (2b) clinical trial.
• The trial was investigating a combination therapy of an mRNA vaccine and immunotherapy (a drug that stimulates an immune response) in advanced-stage melanoma patients.
• After one year of treatment in 157 patients, they found the combination reduced the risk of cancer recurrence or death by 44%.
• Now, Moderna and Merck plan to follow up their initial trial with a phase 3 trial for advanced melanoma in 2023. Phase 3 trials test for safety and efficacy in larger groups of patients.
• BioNTech has several mRNA cancer candidates in the works, including for advanced melanoma, ovarian cancer and non-small cell lung cancer.
• A third company called CureVac is also developing mRNA vaccines targeting a range of cancers including ovarian, colorectal, head and neck, lung and pancreatic.

5. When will they become available?

• Moderna and Merck's mRNA cancer vaccine was fast-tracked for review by the US FDA in February 2023.
• Australia's Therapeutic Goods Administration has not approved the use of mRNAs for use either alone or with other cancer treatments yet.
• In January 2023, the United Kingdom's National Health Service partnered with BioNTech to fast-track the development of mRNA cancer vaccines over the next seven years. Eligible UK cancer patients will get early access to clinical trials from late 2023 onwards.
• In Australia, BioNTech is establishing its Asia-Pacific mRNA clinical research and development centre in Melbourne, in partnership with the Victorian Government. This would develop mRNA vaccines for research and clinical trials, including personalised cancer treatments.
• Moderna will develop Australia's first large-scale mRNA vaccine facility at Monash University by 2024, in partnership with the state and federal government. This will give Australians priority access to mRNA vaccines made locally.

6. What technology is used for?

• Aside from cancer, there is huge potential to use mRNA technologies across many gene therapies.
• There are studies underway testing mRNA vaccines for various diseases such as evolving COVID strains, seasonal influenza, malaria, HIV, cystic fibrosis and even allergies, giving new hope for many previously incurable diseases.

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