PARP Inhibitors in Ovarian Cancer - Episode 4

Clinical Use of Niraparib in Ovarian Cancer

Matthew A. Powell, MD:Niraparib was actually approved in the maintenance setting. It’s the 1 unique PARP inhibitor that doesn’t have the treatment indication yet, so this should follow actually 2 prior platinum therapies. Niraparib also was approved without any indication for molecular testing, so we don’t need to know theBRCAstatus for these patients.

So, what we’ve learned from these trials is there are manageable toxicities with niraparib. We know that platelet toxicity is one that’s probably most notable. And certainly, as clinicians, we need to be on our toes for this, and we should be monitoring our patients closely and doing weekly labs for the first month. And then anytime we make dose adjustments, we should be doing weekly laboratory studies with a CBC, monitoring platelets. And we’ve actually identified a population of patients who are thinner and starting therapy with a lower platelet count. So, I believe if their weight is less than 77 kg or their platelet count is less than 150,000, we want to think about probably starting those patients on 200 mg per day rather than the normal 300-mg starting dose.

The PRIMA trial is the up-front trial looking at standard chemotherapy followed by niraparib, and this is a randomized trial. Again, we hope to have those results out in early 2019. QUADRA is a trial really designed to have niraparib end up with the same type of label indication as the other 2 PARP inhibitors. So, this is in patients whom we have in a treatment-type setting, and the preliminary results at least that have been released publicly show this to be very active in patients withBRCA-mutated status, wild type, platinum resistant, or are platinum refractory. We see actually quite nice response rates in that population. I believe we’ll see another formal presentation of this at ASCO 2018. The other trial I would like to mention is TOPACIO, which is a combination of niraparib plus a PD-1 inhibitor. This was presented at the SGO 2018. I think there will be an update at ASCO 2018 showing a very nice response rate and disease control with a combination of an immunotherapy agent and niraparib.

Transcript edited for clarity.