PARP patrol.

VigiAccess is back to help us detect a heretofore unrecognized potential side effect of PARP inhibitors. When PARPi-reported adverse events were compared to all reported adverse events (all 20+ million), the “reporting odds ratio” of experiencing pancytopenia with any PARPi versus any other drug was 5.5, and this remained significant for each of the five PARPi classes included in the database. There were 201 reported cases with a median latency of 1.6 months from first dose to onset. More ominous is that a notable proportion of reported cases of PARPi-related pancytopenia evolved into myelodysplastic syndrome or acute myeloid leukemia. Granted, there’s no real denominator here of rate of pancytopenia across all patients who take a PARPi, but there seriousness of the outcome warrants caution with CBC monitoring. | Morice, JAMA Oncol 2021