Another First in Cancer: A Memory Cancer Vaccine

Developed to activate the immune system against cancer, cancer immunotherapies are attracting increasing interest, and new approaches are being tested. As shown in the figure below, there are 5 main types of cancer immunotherapy. The new goal is both to combine these immunotherapies and activate memory immune cells against cancer, providing a long-lasting treatment response .

Entering cancer treatment after 2011 and now FDA-approved in around 15 main cancer types, immune checkpoint inhibitor immunotherapies transformed oncology practice and therefore were recognized with the 2018 Nobel Prize in Medicine. However, immune checkpoint immunotherapies work only in some cancers, and even when effective, the risk of recurrence or treatment resistance remains. Cellular immunotherapy in the form of CAR-T cells has shown very little evidence of efficacy in solid organ tumors and is approved only for leukemias and lymphomas .

Unlike chemotherapy, immune checkpoint immunotherapies produce long-lasting responses in patients who benefit. But the truly exciting development is adding adoptive cellular therapies specific to the patient's tumor to immune checkpoint immunotherapies. One type of adoptive cellular immunotherapy is modified natural killer cell therapy.

Our Natural Killer Cells Are Thought to Be the Main Innate Immune Protective Mechanism Against Cancer

On 7 November 2018, NantKwest, an innovative immunotherapy development company, announced natural killer and memory cancer vaccine immunotherapypromising results from human clinical trials testing this approach.

The main features of this clinical trial, running from August 2017 to October 2018, were:

• Previously heavily treated patients with treatment-resistant, metastatic (advanced) cancers of different types, totaling 30, were enrolled.
• The 30 patients received 300 cancer vaccine doses.
• Cytokine release syndrome, which can be a serious adverse effect of cellular cancer therapies, occurred in none of these cases.
• Previously treated with at least 4 lines of therapy, patients with metastatic triple-negative breast cancer had % 80 disease control,
• Patients with metastatic pancreatic cancer previously treated with at least 3 lines achieved % 80 disease control and median survival of 9.5 months. In advanced pancreatic cancer patients receiving standard line 1 treatment, this duration is known to be 8.7 months.
• Metastatic head and neck cancer patients previously treated with at least 4 lines achieved, with the memory cancer vaccine, % 67 disease control and a complete response in 1 patient.
• In treatment-resistant early-stage (carcinoma in situ) bladder cancer, administration alone of the IL-15 fusion protein activating the body's natural killer cells achieved a % 86 complete response.

Conclusion

Alongside stimulating patients' own natural killer (NK) cells and T lymphocytes with activators such as IL-15, giving memory NK cells developed in the laboratory through genetic engineering as a cancer vaccine may be effective in advanced solid tumors.