The efficacy and safety of hetrombopag for chemoradiotherapy-induced thrombocytopenia in patients with gynecologic malignancies: a single-arm exploratory trial

To explore the preliminary efficacy and safety of hetrombopag for chemoradiotherapy-induced thrombocytopenia in gynecologic malignancies. This single-arm trial enrolled Chinese patients with gynecologic malignancies between 2021 and 2024. Patients with grade 1–2 thrombocytopenia initiated hetrombopag at 5.0 mg/day, while those with grade 3–4 started at 7.5 mg/day. Oral administration continued until the platelet count reached ≥ 100 × 10⁹/L or treatment failure. All patients continued concurrent chemoradiotherapy (CCRT). The primary endpoint was the proportion of patients achieving a platelet count ≥ 100 × 10⁹/L within 14 days. Secondary endpoints included the proportion of patients achieving a platelet count ≥ 100 × 10⁹/L within 7 days, the median time to achieve a platelet count ≥ 100 × 10⁹/L within 14 days, and a composite endpoint defined as meeting at least one of the following: platelet count ≥ 100 × 10⁹/L, an increase of ≥ 50 × 10⁹/L from baseline, or a doubling of baseline platelet count. Among 37 patients, only one required platelet transfusion. Thirty patients (81.1%) achieved a platelet count ≥ 100 × 10⁹/L within 14 days and 19 (51.4%) achieved a platelet count ≥ 100 × 10⁹/L within 7 days. The median time to achieving a platelet count ≥ 100 × 10⁹/L within 14 day was 6.0 days (95% CI: 6.0, 15.0). Thirty patients achieved the composite endpoint. An upward trend in mean platelet counts from baseline was observed during the early treatment phase. Treatment-emergent adverse events occurred in 91.9% (34/37). No serious adverse events were observed. Hetrombopag showed potential clinical activity and a manageable safety profile in managing thrombocytopenia in patients with gynecologic malignancies undergoing CCRT. These preliminary findings warrant further validation in randomized controlled trials. ClinicalTrials.gov (NCT05160857). Registration Date: December 16, 2021.