PARP Inhibitors in the Management of Ovarian Cancer - Episode 10
John L. Fox, MD: There are a lot of gaps in the treatment of ovarian cancer. The most glaring is probably the availability of a screening test to help identify patients early. Ovarian cancer accounts for 1.5% of all cancers in the United States, but it is the fifth leading cause of death in women because it’s usually detected in later stages, stage 3 or 4. So, identifying screening tests or developing screening tests that could help identify patients earlier is a critical gap that exists.
Another gap has clearly been in the treatments available for women with advanced-stage ovarian cancer. Until the approval of Avastin (bevacizumab) in the last 3 or 4 years for the treatment of women with advanced ovarian cancer, we had no new developments in treatment. So, Avastin was the first new treatment available in a number of years, and now more recently with the advent of PARP inhibitors, we have a number of new therapeutics available.
And yet, the real challenge with all these new therapeutics is that all the PARP inhibitors have been approved based on indirect evidence with their progression-free survival or overall response rate. What patients want to know, what providers want to know, and what payers want to know is, does this deliver an outcome that’s relevant to patients? Progression-free survival is a common metric that the FDA uses in the accelerated approval process, and yet there is not always a strong correlation between the progression-free survival and overall survival.
One of the real challenges with the recent advances in the treatment of advanced ovarian cancer is just the number of variables that have to be taken into consideration. First, it’s the line of therapy. Is this first-line therapy or is this treatment after platinum therapy? Is this a platinum-resistant patient or a platinum-sensitive patient? Is there a BRCA mutation, yes or no? If they had a BRCA mutation, was it a germline mutation or a somatic mutation? Is this treatment or is this maintenance therapy? Does this patient have loss of heterozygosity or not?
There are a whole host of variables, so maintaining access to these drugs is going to be very complicated. And so, it requires that we evaluate the evidence critically and that we ensure we have close communication with providers to ensure that they understand what evidence we’re looking fof—what information we’re looking for—in a health plan, so that we make the most appropriate coverage decision for that patient.