Use of romiplostim for antineoplastic therapy-induced thrombocytopenia in gynecologic and breast cancers.

Objective: Romiplostim is used to treat chemotherapy-induced thrombocytopenia in a variety of tumor types; however, few studies have examined its use in breast and gynecologic cancers. We evaluated platelet response and durability of response to romiplostim in patients with gynecologic or breast cancer complicated by chemotherapy-induced thrombocytopenia. Methods: We retrospectively identified 33 patients with gynecologic or breast cancer who received romiplostim between 07/1/2021-07/31/2022 at an academic cancer center. Results: Thirty-three patients met inclusion criteria; 26 (79 %) had breast cancer, 4 (12 %) had ovarian cancer, and 3 (9 %) had endometrial cancer. Twenty patients (61 %) experienced treatment delays and 12 (36 %) required dose reductions prior to starting romiplostim for chemotherapy-induced thrombocytopenia, with some patients experiencing both. Eleven patients (33 %) did not undergo a dose reduction or delay prior to initiation of romiplostim. Median platelet count prior to romiplostim therapy was 53 k/mcL (range, 40.5-78.8). Median platelet count within 3 weeks following initiation of romiplostim was 147 k/mcL (range, 31-562). Twenty-one patients (64 %) achieved platelet correction within 3 weeks, of whom 10 (48 %) resumed anticancer therapy and maintained platelet levels above 100 k/mcL at 8 weeks. Twelve patients did not achieve platelet correction within 3 weeks of romiplostim initiation; 4 (33 %) required a treatment change secondary to persistent thrombocytopenia, 3 (25 %) required a treatment dose reduction, 3 (25 %) were deemed too ill to continue therapy, and 2 (17 %) required a treatment delay. Conclusions: Romiplostim facilitated the resumption of anticancer therapy in 64 % of patients with gynecologic or breast cancer complicated by chemotherapy-induced thrombocytopenia.