Patients with platinum-sensitive recurrent ovarian cancer showed significantly improved cancer-free survival with Tesaro (niraparib) in the first clinical trial directly comparing a poly(ADP)-ribose polymerase (PARP) inhibitor with chemotherapy.Tesaro improved cancer-free survival by 73% in patients with a BRCA mutation and by 55% in those without such mutations. The new data were presented at the 2016 European Society for Medical Oncology (ESMO).Each year in the United States, approximately 22,000 women are diagnosed with ovarian cancer, and is the fifth most common cause of cancer-related deaths among women. Since there are no generalized screening methods for the early detection of ovarian cancer, the majority of ovarian cancer is detected in advanced stages, once it has spread from the ovaries.
Although patients often respond to initial therapy that includes platinum-based chemotherapy, approximately 90% of patients will experience a progression of their cancer within 2 years of their initial therapy.Tesaro is classified as a PARP inhibitor. The family of proteins referred to as PARP play many roles in the functioning of a cell. It is thought that PARP inhibitors suppress the ability of cells to fix their damaged DNA.In the current study patients with recurrent ovarian cancer after at least two platinum-based chemotherapies were treated with Tesaro 300 mg or a placebo once daily. In addition 203 of the 533 enrolled patients had a germline BRCA mutation.Overall survival without cancer progression was improved in patients with or without a germline mutation. Individuals with a germline mutation treated with Tesaro survived 21.0 months without cancer progression compared to 5.5 months, and those without a mutation survived 9.3 compared to 3.9 months.
Dr. Sandro Pignata, MD, PhD, Director of the Instituto Nazionale Tumori, IRCCS Fondazione Pascale, in Napoli, Italy, described the findings as a “significant step forward in the treatment of ovarian cancer” and suggested that Tesaro may fundamentally change the way we treat ovarian cancer.Personalized medicine has arrived in the management of ovarian cancer and future studies are needed to unravel which patients with ovarian cancer are not responders to PARP inhibitors and why, and which patients are long responders and why.
Study leader Mansoor Raza Mirza of Copenhagen University believes that case has now been made.”Our conclusion is that all patients have a benefit and all patients must be treated,” he told reporters at the meeting.”This is a breakthrough for patients with ovarian cancer. We have never seen such large benefits in progression-free survival (PFS) in recurrent ovarian cancer.”