Background: Rolapitant, a long-acting neurokinin-1 receptor antagonist, protected against CINV in patients receiving highly or moderately emetogenic chemotherapy (HEC or MEC). Methods: In 3 double-blind phase 3 studies, patients were randomized to receive oral rolapitant 180 mg or placebo before administration of HEC or MEC. All patients received a 5-hydroxytryptamine type 3 receptor antagonist and dexamethasone. In a post hoc analysis of 3 pooled studies (2 HEC and 1 MEC), we assessed the efficacy and safety of rolapitant in patients with gynecologic (ovarian, uterine, or cervical) cancer. Endpoints included complete response (CR; no emesis and no use of rescue medication), no emesis, no nausea (maximum visual analogue scale [VAS] < 5 mm), and complete protection (CP; no emesis, no use of rescue medication, and no significant nausea [maximum VAS < 25 mm]) in the overall (0–120 h), acute ( ≤ 24 h), and delayed ( > 24–120 h) phases. Results: Of 203 patients with gynecologic cancer, 55% received cisplatin-based HEC and 45% received MEC (98% of whom received carboplatin-based therapy). In the overall and delayed phases, improved rates of CR, no emesis, no nausea, and CP were observed with rolapitant compared with control (Table). The overall incidence of treatment-emergent adverse events was similar in the rolapitant and control groups (46% vs 54%). Conclusions: Rolapitant protected against overall and delayed CINV in patients with gynecologic cancer receiving HEC or MEC. Clinical trial information: NCT01500226, NCT01499849, NCT01500213