Subgroup analyses from the phase 3 PANOVA-3 trial of tumor treating fields (TTFields) with gemcitabine/nab-paclitaxel in locally advanced pancreatic adenocarcinoma: Efficacy and safety by sex, age, and body mass index (BMI).

Abstract

707 Background: Due to insufficient data, therapy for unresectable, locally advanced pancreatic adenocarcinoma (LAPAC) is based on trials in metastatic disease, and outcomes remain poor. TTFields disrupt cancer cell division using alternating low-frequency electric fields delivered externally by a portable device. In the phase 3 PANOVA-3 trial (NCT03377491), TTFields with gemcitabine/nab-paclitaxel (GnP) significantly improved overall survival (OS; HR 0.82) and pain-free survival (HR 0.74) vs GnP in patients with unresectable LAPAC. Methods: In PANOVA-3, patients with newly diagnosed LAPAC were randomized 1:1 to receive GnP with or without concomitant TTFields. Kaplan-Meier methodology was used for time-to-event analyses. Response evaluations were based on RECIST V1.1. OS, pain-free survival, and safety were analyzed post-hoc in subgroups based on sex (male, female), age ( < 65, ≥65 years), and BMI (<25, ≥25 kg/m 2 for efficacy; ≤20, 20–25, 25–30, ≥30 kg/m 2 for safety). Differences between treatment arms were compared using the log-rank test. Results: Efficacy outcomes are shown in the table. TTFields significantly extended pain-free survival in females and patients ≥65 years. Device-related adverse events (AEs) were comparable between sexes, older and younger patients, and across BMI ranges. Some device-related skin adverse events occurred more frequently in females (e.g. dermatitis, 33.1% vs 22.7%; rash 21.8% vs 13.5%, females vs males, respectively); others occurred more often in males (e.g. maculo-papular rash, 9.8% vs 14.2%; erythema, 9% vs 12.1%, females vs males, respectively). Dermatitis and pruritus had a higher incidence in the BMI ≥30 kg/m 2 subgroup (38.5%), whereas patients with BMI <30 kg/m 2 did not show noticeable differences in device-related AEs. Skin irritation (11.5% vs 5.5%) and skin reactions (8.5% vs 2.8%) were more common in patients ≥65 years than patients <65 years. Conclusions: Median OS and pain-free survival in these post-hoc subgroup analyses are generally consistent with the overall analysis, supporting use of TTFields with GnP in unresectable LAPAC. No new safety concerns were noted; observations were consistent with the general PANOVA-3 population. Clinical trial information: NCT03377491 . Survival outcomes for the subgroup analyses. Median OS, months TTFields + GnP GnP P value Age<65 years≥65 years 18.6 (n=113)15.4 (n=172) 16.0 (n=114)12.9 (n=172) 0.2060.061 SexFemaleMale 16.8 (n=138)15.7 (n=147) 14.5 (n=161)13.4 (n=125) 0.1140.145 BMI<25≥25 16.7 (n=166)16.2 (n=117) 14.2 (n=174)14.5 (n=108) 0.1550.105 Median pain-free survival, months Age<65 years≥65 years 16.5 (n=113)13.1 (n=172) 9.2 (n=114)8.3 (n=172) 0.4070.035 SexFemaleMale 16.5 (n=138)15.2 (n=147) 8.3 (n=161)9.3 (n=125) 0.0260.478 BMI<25≥25 16.6 (n=166)14.7 (n=117) 9.1 (n=174)8.3 (n=108) 0.1170.088