The overall survival (OS) benefit seen with PARP inhibitors in clinical trials in ovarian cancer have not translated to the real world, a new study suggests.
Randomised clinical trials have previously shown significantly improved progression-free survival (PFS) with PARP inhibitors in patients with platinum-sensitive relapsed ovarian cancer. However, this new study, published in the International Journal of Gynecological Cancer, found overall survival was shorter in real-world UK practice compared with clinical trials.
This retrospective chart review was undertaken across 13 NHS Trusts in England, Wales, and Scotland. Patients were included if they had platinum-sensitive relapsed high-grade serous ovarian cancer and had responded to second-line platinum-based chemotherapy. A total of 233 patients met the inclusion criteria. Patient characteristics were consistent with other published data, with a median age of 61 years (range 35-85).
Median OS from the time of response to second-line platinum-based chemotherapy in this retrospective study was 19.3 months (95% CI 1.5-128.2). In comparison, in Study 19, median OS from the time of response to second-line or later-line platinum-based chemotherapy was 27.8 months, however this figure was confounded by post-progression PARP inhibitor use in 13% of patients. Mature OS data from other trials are not yet available.
Median PFS decreased from 7.3 months (n=233) following second-line therapy to 4.4 months (n=144) for third-line treatment. These findings are consistent with clinical trials.
The median number of lines of treatment in this real-world study was three. This is relatively low, considering women in trials often receive multiple lines of therapy, emphasizing the need for early effective therapies.
The findings highlight that earlier intervention is key in order to extend time to progression, delay the onset of platinum resistance, and ultimately improve response rates and overall survival.