Randomized phase 2 trial of tremelimumab and durvalumab in combination versus sequentially in recurrent platinum-resistant ovarian cancer

BackgroundSingle-agent immune checkpoint inhibitors (ICIs) have demonstrated limited responses in recurrent ovarian cancer; however, 30%-40% of patients achieve stable disease. The primary objective was to estimate progression-free survival (PFS) after sequential versus combination cytotoxic T-lymphocyte antigen 4 and programmed death ligand 1 ICIs in patients with platinum-resistant high-grade serous ovarian cancer (HGSOC).MethodsPatients were randomized to a sequential arm (tremelimumab followed by durvalumab on progression) or a combination arm (tremelimumab plus durvalumab, followed by durvalumab) via a Bayesian adaptive design that made it more likely for patients to be randomized to the more effective arm. The primary end point was immune-related PFS (irPFS).ResultsSixty-one subjects were randomized to sequential (n = 38) or combination therapy (n = 23). Thirteen patients (34.2%) in the sequential arm received durvalumab. There was no difference in PFS in the sequential arm (1.84 months; 95% CI, 1.77-2.17 months) compared with the combination arm (1.87 months; 95% CI, 1.77-2.43 months) (p = .402). In the sequential arm, no responses were observed, although 12 patients (31.6%) demonstrated stable disease. In the combination arm, two patients (8.7%) had partial response, whereas one patient (4.4%) had stable disease. Adverse events were consistent with those previously reported for ICIs. Patient-reported outcomes were similar in both arms.ConclusionsThere was no difference in irPFS for combination tremelimumab plus durvalumab compared to tremelimumab alone (administered as part of a sequential treatment strategy) in a heavily pretreated population of patients with platinum-resistant HGSOC. Response rates were comparable to prior reports, although the combination regimen did not add significant benefit, as has been previously described. There was no difference in the median progression-free survival for combination tremelimumab plus durvalumab compared to tremelimumab alone (administered as part of a sequential treatment strategy) in a heavily pretreated population of patients with platinum-resistant high-grade serous ovarian cancer. The adverse event profile was consistent with that previously reported for immune checkpoint blockade, and patient-reported outcomes were similar in both arms.