Identifying New Combinations of Therapy to Combat Ovarian Cancer Drug Resistance

Ovarian cancer is usually diagnosed at a late stage, after cancer cells have already spread to other organs. Ovarian cancer is hard to diagnose due to vague initial symptoms such as abdominal pain, changes in digestion and fatigue. It is the fifth most common cancer in Canadian women¹. New research can provide improvements in treatment of ovarian cancer. A recent study on a new drug called Fostamatinib has shown it could help combat hard to treat drug, drug resistant ovarian cancer.

One of the major challenges facing both cancer researchers and doctors is when cancer cells become resistant to therapy². For woman with advanced ovarian cancer, a drug called Paclitaxel is often the treatment of choice. Although most patients will initially respond, the majority of women will develop treatment-resistant tumours and only 10-15% will survive in the long-term³. Recently, researchers from John Hopkins University discovered a new treatment combination that may address this problem. They found that combining a new, experimental drug called Fostamatinib with existing drug Paclitaxel, could help to overcome treatment resistance . The research was carried out using ovarian cancer cells grown in the lab, as well as in mice. One really interesting finding is that when these drugs were given in combination, they were able to shrink the size of ovarian cancer tumours in mice by more than 60% versus mice which did not receive treatment.

The researchers believe that Fostamatinib works to overcome resistance to Paclitaxel by targeting a specific enzyme, called STK (or spleen tyrosine kinase). This particular enzyme is found at high levels in recurrent ovarian cancer tumours (i.e. tumours that returned after initial treatment) and in ovarian cancer tumours that are already resistant to Paclitaxel.

Although a promising study, these results are still in their early infancy and more work needs to be completed before we can see this treatment combination being used to cure ovarian cancer. Specifically, Fostamatinib, has not yet been approved by the Food and Drug Administration (FDA) in the United States nor by Health Canada. The researchers at John Hopkins are hoping to move their findings to the clinic by planning a Phase 1 clinical trial⁴. This clinical trial will test the dosage and safety of Fostamatinib in a small number of women with advanced ovarian cancer. It may take several years before we will learn whether this new drug combination can offer hope to ovarian cancer patients. In the meantime, it is comforting to know that researchers are working hard to address the significant challenge related to drug resistant tuomours, in hopes of helping patients with advanced forms of the disease.

This blog is written by Katayoun Seif Farahi. Katayoun wants to thank Stefanie Freel, Kelly Fathers, and Katie Wright for their invaluable inputs. Katayoun is an International Medical Graduate. She is a volunteer at the Canadian Cancer Society and the Research Outreach Information Team in Toronto. She is interested in health and research. She is seeking new opportunities in field of research and health.

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