Promising developments in cancer treatment are underway as researchers use genomic sequencing and genetic testing to better target and treat more specific aspects of ovarian cancer. Doctors and researchers discussed these exciting advancements this past July at the Ovarian Cancer National Conference in Washington D.C.
Those diagnosed with ovarian cancer may initially believe their only options are treatments like chemotherapy, but researchers continue to make important headway in multiple forms of treatment.
PARP Inhibitors for BRCA Gene Mutations
Women whose tumors hold BRCA gene mutations may now try PARP inhibition in new trials and as an approved drug in some cases. The drug works by obstructing the PARP enzyme, which functions like an ambulance rushing to a DNA break, and if the enzyme can’t reach the break to correct it, the cancer cell ultimately dies.
Currently, several PARP inhibiting drugs are approved for female patients with BRCA-mutated ovarian cancer which continued to progress after chemotherapy. New trials wish to expand PARP inhibitor use — the phase three SOLO1 trial assessed Lynparza, or olaparib, in comparison to a placebo to prevent recurrence or progression after the patient’s first treatment once diagnosed with stage three or four high-grade endometrial or serous cancer. Patients who took olaparib experienced longer periods before the disease progressed than those who didn’t take the drug.
Three other trials — NOVA, SOLO2 and ARIEL 3 — all revealed improvements in longer periods of cancer remission after treatment with chemotherapy than the placebo. PARP combinations also prove highly effective, such as Lynparza with cediranib, which inhibits VEGF protein activity. The combination proved more effective than the use of Lynparza alone, which led to more trials designated by the National Cancer Institute (NCI). The combination worked best in female cancer patients without a BRCA mutation.
Such trials sponsored by the NCI are often an initial and last step for many cancer patients, but only five percent participate in clinical trials despite the prospective benefits. Patients may receive the standard care of treatment or test out a new drug or treatment that they hope will increase their chances of remission.
Single-Agent Immunotherapy
From lung to bladder cancer, specialists use checkpoint inhibitor immunotherapy drugs to treat many types of cancer, and these may prove effective for ovarian patients with a particular subset of the cancer. Checkpoint inhibitors work by interfering with cancer cell signals and alert T-cells to attack and destroy the cancer cells.
Keytruda (pembrolizumab) recently received accelerated approval due to an initial study that showed partial or complete tumor shrinkage of 39.6 percent who had cancer types with impairments in DNA repair. Phase two of the KEYNOTE-1 study looked at the efficacy of Keytruda (pembrolizumab), the inhibitor that blocks the protein PD-L1, in patients suffering from recurring advanced ovarian cancer patients, but the response rate came back as only eight percent. This rate is consistent with other scores from signal-agent trials.
Studies are ongoing for research in checkpoint inhibition, and those patients who have more PD-L1 cells inside their tumors experience an improved response rate, also known as a higher combined positive score (CPS). Those with a CPS of less than one only had a one percent rate of response compared with a 17.1 response rate in those patients who possessed a CPS 17 score or higher. Though a small population, this group may receive effective treatment with checkpoint inhibition immunotherapy.
Vaccines
Don’t discount vaccines from the treatment space in ovarian cancer as they hold the potential to prime tutors to better respond to checkpoint inhibitor immunotherapy, which proves most effective on tumors that possess multitudes of gene mutations — also known as “hot” tumors. The vaccine would work to transform a “cold” tumor into a “hot” tumor, prepping it for treatment with checkpoint inhibitors.
Currently, research on vaccine use in ovarian cancer centers around how these vaccines may be personalized for particular patients and how the proteins targeted represent the disease. A promising study in the works at the Dana-Farber Cancer Institute aims to analyze a vaccine that will target neoantigens, types of protein generated by genes the cancer mutated from its progression. Unfortunately, the study currently faces roadblocks in the cost of making the vaccines and finding the expertise to do so.
The possibility of what might be achieved with these new discoveries and advancements may help bring a lot of relief to cancer patients. The vast amount of research underway in this area promises to significantly improve how we treat ovarian cancer in the future.
Kate is a health and political journalist. You can subscribe to her blog, So Well, So Woman, to read more of her work and receive a free subscriber gift! https://sowellsowoman.com/about/subscribe/