Experts Discuss Indications for PARP Inhibitors

In a Directions in Oncology Pharmacy^TM Peer Exchange series, experts explained the right time to use bevacizumab, either as a front-line therapy or at the time of disease progression.

Bevacizumab is currently approved by the FDA for indications in platinum-resistant patient population, platinum-sensitive recurrent population, and as a frontline therapy. However, according to Michael Birrer, MD, PhD, there is some debate surrounding the right time to use bevacizumab.

The AURELIA study found results in patients who were platinum-resistant and was the first indication in the United States. The GOG-213 and OCEANS studies included patient populations who were in the platinum-sensitive recurrence. Furthermore, there was approval based on GOG-218 for use of bevacizumab as a frontline therapy in 2019.

“You have an advantage of progression-free survival (PFS) anywhere between 4 and 6 months, depending on the cancer antigen 125 (CA-125). I find it easy to give. I’ve never had a patient come off based on hypertension or bowel perforation,” Birrer said.

However, Birrer added that there is an argument to be made for waiting to give the drug, explaining that hazard ratios actually “get better” as the natural history of the disease progresses.

“[W]e’re trying to integrate bevacizumab with the use of PARP inhibitors. I think it provides us with a lot of opportunities to tailor the therapy according to the needs of the patient. So, patients who have high-risk disease with a lot of ascites, they’d probably get BEV [bevacizumab],” Birrer said.

According to R. Wendal Naumann, MD, there are not many FDA-indicated PARP inhibitors at the given moment, but there may be some in the pipeline. Additionally, Naumann believes that PARP inhibitors should be offered to patients as maintenance therapy to keep pressure on the tumor. However, there is still debate surrounding whether the therapy will lead to survival advantage, particularly in patients with HRD, which is likely to benefit from them.

Birrer ended the discussion by explaining that it is a problem if a patient with ovarian cancer does not see a PARP inhibitor.

“The only question is sequence to me, when and where, and do you combine it with other drugs? We can talk about those trials, but this is a whole new class of drugs that has changed, fundamentally, our management of ovarian cancer patients,” Birrer said.