There are a variety of drugs that target blood vessel formation such as VEGF inhibitors and Ang 1 and 2 inhibitors. VEGF inhibitors interfere with the blood supply to tumours, thereby inhibiting tumour growth, and possibly leading to tumour shrinkage. Ang 1 and 2 inhibitors, are medications designed to stop the development of blood vessels in cancer tissues. These drugs have shown encouraging results. GOC would like to have these drugs available as an option as they do add benefit over and above the use of regular chemotherapy. These drugs are not a cure but they do have the important ability to prolong the time that the cancer stays in remission (decrease in size or disappearance of the cancer, and most of their side effects are manageable. Most of the data comes from studies where the drugs were combined with chemotherapy or given as maintenance therapy (the ongoing use of a drug after chemotherapy treatment to help slow the rate of the cancer returning) after chemotherapy. There is more evidence available for bevacizumab (clinical name for Avastin) than there is for the other drugs. GOC members favoured using bevacizumab in combination with chemotherapy in the resistant relapse setting (cancer regrew within 6 months). There is no high level data on their use as a single agent (one drug vs. a combination of drugs) but this would be another treatment option.
Full GOC position statement regarding the use of anti-angiogenic therapies in epithelial ovarian carcinoma
The use of PARP inhibitors was discussed at the Society of Gynecologic Oncology of Canada’s (GOC) December 2014 Communities of Practice Forum. PARP is a protein inside cells in the body that helps repair damage to DNA, which is the genetic material that carries the instructions for the body’s growth and development. Research has shown that PARP inhibitors
stop the PARP protein from working and that can sometimes cause cancer cells to stop growing. The universal consensus was that PARP inhibitors would be a useful treatment option for BRCA positive women with platinum sensitive, relapsed epithelial ovarian cancer (cancer that regrew more than 6 months from the last dose of a platinum regimen). This family of drugs is a treatment advance and importantly, a small group of patients treated with a PARP inhibitor had unexpectedly long durations of remission/benefit (decrease in size or disappearance of the cancer) which we would not expect to see with standard chemotherapy.
Since this meeting, both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have approved the drug olaparib. The FDA approved it as a stand-alone therapy and the EMA approved it as maintenance therapy (the ongoing use of a drug after standard chemotherapy treatment to help slow the rate of the cancer returning) for women with platinum sensitive, recurrent ovarian cancer who have a mutated BRCA gene, and who have responded to their latest round of chemotherapy. It is not clear as yet to the members of GOC as how to most effectively use PARP inhibitors. There are multiple, soon to be completed studies, which will provide more information. Important as yet unanswered questions are: 1) are there patients without inherited BRCA mutation that could also benefit and 2) would the drugs be more effectively used as an alternative to standard chemotherapy instead of as maintenance therapy after completing standard chemotherapy.
Full GOC Position Statement Regarding the Use of Parp-Inhibitors in the Treatment of Recurrent High Grade Serous Ovarian Cancer