Patient self-reporting of tolerability using PRO-CTCAE in a randomized double-blind, placebo-controlled phase II trial comparing gemcitabine in combination with adavosertib or placebo in patients with platinum resistant or refractory epithelial ovarian carcinoma

Background: A double-blind, randomized, placebo-controlled, phase 2 trial assessed gemcitabine in combination with the wee1 inhibitor adavosertib or placebo in platinum resistant or refractory high grade serous ovarian cancer (HGSOC), demonstrating improved progression free and overall survival favouring the adavosertib/gemcitabine arm. An exploratory objective of the study included the PRO-CTCAE assessment, to capture self-reporting of frequency, severity and/or interference of symptomatic adverse events (syAEs).

Methods: PRO-CTCAE items at baseline, days 1 and 15 of each cycle and off treatment, were completed in two centres, with the objective of characterizing syAEs in the first three months of therapy. The maximum post-baseline score proportion for each syAE was tabulated per patient. The 12-week area under the curve (AUC12w) as a measure of syAE over-time and incremental AUC12w (iAUC12w) for adjustment to baseline syAEs.

Results: Sixty-one patients were approached for PRO-CTCAE surveys and 55 were evaluable. Among patients with HGSOC, 28 received gemcitabine/adavosertib (arm A) and 19 gemcitabine/placebo (arm B). Survey completion rates were high. The proportion of participants with positive (≥1) PRO-CTCAE scores was higher for difficulty swallowing with gemcitabine/adavosertib (arm A 35.7% vs arm B 5.3%, p = 0.02). The high score (≥3) syAEs showed more frequent diarrhea with gemcitabine/adavosertib (arm A 25% vs arm B 0%, p = 0.03). The proportions of worsening syAEs over time were higher in patients receiving gemcitabine/adavosertib for difficulty swallowing (arm A 35.7% vs arm B 5.3%; p = 0.03) and fatigue severity (arm A 71.43% vs arm B 42.1%; p = 0.04).

Conclusions: The longitudinal assessment of patient self-reported tolerability showed greater difficulty swallowing and fatigue severity in patients receiving gemcitabine/adavosertib, compared to gemcitabine/placebo. PRO-CTCAE provides complementary and objective assessment of drug tolerability from a patient's perspective.