1862P - A single-arm, phase II trial of hetrombopag for the treatment of concurrent chemoradiotherapy-induced thrombocytopenia in patients with advanced solid tumors

Background

Thrombocytopenia represents one of the main toxicities of concurrent chemoradiotherapy, which may necessitate chemotherapy dose reductions, dose delays, or discontinuation, and even compromise survival. Hetrombopag, a thrombopoietin receptor agonist, has shown efficacy and safety in patients with chemotherapy-induced thrombocytopenia. However, the efficacy of hetrombopag in patients who received concurrent chemoradiotherapy is not clear yet. This study aimed to evaluate the efficacy and safety of hetrombopag in this patient population.

Methods

In this single-arm, phase II study, patients aged 18 years or older with solid tumors who experienced chemoradiotherapy-induced thrombocytopenia [platelet count (PLT) ≤75×10⁹/L] were enrolled. Eligible patients received oral hetrombopag at an initial dose of 7.5 mg QD until PLT ≥ 100 × 10⁹/L. In the maintenance phase, the dose of hetrombopag was modified to maintain PLT levels between 100-400 × 10⁹/L until concurrent chemoradiotherapy was completed. The primary endpoint was the proportion of patients with PLT≥ 100×10⁹/L after study treatment.

Results

A total of 28 patients were enrolled between May 2022 and March 2024. The median age was 65.0 (range: 46.0-74.0) years. All patients were in clinical stage III/IV. The mean PLT before hetrombopag treatment was 59.5 (±13.5) ×10⁹/L. After study treatment, the proportion of patients with PLT≥ 100×10⁹/L was 78.6% (22/28), and the proportion of patients with PLT≥ 75×10⁹/L was 82.1% (23/28). The median durations from the first dose of hetrombopag to PLT≥ 100×10⁹/L and PLT≥ 75×10⁹/L were 8 (range: 5-11) days and 5 (range: 2-8) days, respectively. Treatment-related adverse events were reported in 10.7% (3/28) of patients, all of which were grade 1, including increased D-dimer (1, 3.6%), increased γ-glutamyl transferase (1, 3.6%), increased aspartate aminotransferase (1, 3.6%).

Conclusions

Hetrombopag is feasible and well tolerated for the management of thrombocytopenia caused by concurrent chemoradiotherapy.

Clinical trial identification

ChiCTR2200057846; (2022/03/19).

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.