For a BRCA1+ patient with a history of stage IVB endometrioid ovarian carcinoma s/p upfront surgery and adjuvant chemotherapy who has now completed 3 years of maintenance niraparib and is NED, how would you counsel about discontinuing vs continuing PARPi therapy?

Recommendation: I recommend that this patient with Stage IVB ovarian cancer, with a complete response to surgery, chemotherapy, and 3 years of maintenance PARPi, be counseled to discontinue niraparib.

Background:

The duration of therapy for primary maintenance PARPi should be tailored based on the associated clinical trial data, e.g., PRIMA for niraparib (3 years) or SOLO1 for olaparib (2 years).^1-3 Note that 35% of patients enrolled in PRIMA had Stage IV disease, and there was no difference in tr...

For this patient who has completed 3 years of niraparib and is NED, discontinuation is reasonable and supported by available evidence. The PFS benefit achieved will likely persist for years after stopping, while continuing exposes her to cumulative toxicity risks without a proven incremental benefit. If continuation is considered, this should involve detailed shared decision-making discussing the lack of data beyond 3 years, increased MDS/AML risk with prolonged exposure, and the need for vigila...

I have a real-life case exactly matching this situation. After completion of 3 years of niraparib as NED and a CA-125 level of 6.6, we discussed the available data and discontinued niraparib. During the follow-ups, at 8 months, CA-125 was 8.8, at 12 months, 15, at 14 months, 22.4, and at 17 months, 59.7 with a positive PET scan.

For the case in question, the decision to discontinue versus continue PARP inhibitor therapy involves balancing the lack of data supporting extended therapy beyond 3 year...