One of the primary focuses in immuno-oncology is how to deliver treatments to make them most effective. Research on these delivery mechanisms ranges from biological markers and personalized medicine to mechanical methods. While immunotherapy has proven especially effective for some patients, others may see little or no benefit, which has spurred researchers to figure out why and, more importantly, develop new techniques for delivering immuno-oncology treatments.
One of the newest delivery methods for melanoma involves the use of a patch covered with very small needles. The use of this patch is to deliver immunotherapy directly to melanoma tumors present on the surface of the skin. The patches use anti-PD-1 therapy, which is the same technique employed by two of the most popular immunotherapy drugs currently on the market, Opdivo and Keytruda. PD-1 is an immune inhibitor that the body uses to protect healthy cells from the immune system. Cancer cells have evolved the ability to take over the PD-1 pathway to provide protection for tumors.
The needle patch delivers the therapy more directly to melanoma cells, which could make it more effective. Therapies like Opdivo and Keytruda are introduced into the bloodstream and travel around the body until they find the cancer site. Injecting the drug directly into the tumor microenvironment could make the outcomes significantly better. The other major benefit of this approach is more control over the side effects of immunotherapy. For instance, autoimmune disorders can occur since anti-PD-1 approaches turn off the body’s defenses against the immune system; however, if the immunotherapy is more localized to the tumor site, the chances of the immune system attacking healthy cells could be mediated.
The patch is still in animal testing for melanoma, so it is far from being commercially available. However, the delivery system has shown significant promise. According to the team, 40 percent of mice treated with the microneedle patch survived and were in remission from melanoma. Among rats in the control group, which received more traditional injections, no mice survived.
The team has also tried combining anti-PD-1 antibodies with other treatments, particularly the antibody that works against CTLA4, another protein involved in inhibiting the immune response. Mice that received the patch with both drugs had a 7- percent survival rate after 40 days. Mice who survived had no detectable melanoma. The results from these trials were published at the end of March 2016 in Nano Letters.
The Threat of Melanoma in the United States
New delivery mechanisms that make cancer immunotherapy more effective are an important part of modern oncological research. The Centers for Disease Control have not published data on melanoma rates since 2012, but in that year alone more than 67,000 Americans were diagnosed with the disease. If individuals catch melanoma in its early stages, the five-year survival rate is as high as 98 percent, says the National Cancer Institute. However, if the cancer has metastasized before diagnosis and the beginning of treatment, then the survivorship figure drops to about 16 percent. In these cases, traditional oncological approaches like chemotherapy, surgery, and radiation therapy are often ineffective. Immuno-oncology has created a lot of excitement in the field as a way of effectively treating the disease.