Dr Masarova on the Investigation of Ropeginterferon Alfa in Essential Thrombocythemia

Lucia Masarova, MD, assistant professor, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses the investigation of ropeginterferon alfa-2b-njft (Besremi) in adult patients with essential thrombocythemia, highlighting the unmet needs that investigators aim to address with this investigation.

Data from the phase 2 EXCEED-ET trial (NCT05482971) of ropeginterferon alfa were presented by investigators at the 2023 ASCO Annual Meeting. To address unmet needs that are present in the treatment of adult patients with essential thrombocythemia, investigators launched the ongoing, single-arm, multicenter trial to assess the efficacy, safety, and tolerability of ropeginterferon alfa. All patients are to be treated with ropeginterferon alfa, which is an injectable agent, Masarova says. This agent will be given at a faster dose escalation than normally conducted in this population, Masarova adds. This agent is given every other week, starting with 250 μg, then 350 μg, and 500 μg as the maximum dose, she says, adding that patients will then stay on treatment for up to 56 weeks. The investigators will then measure control of the platelet counts.

Patients with newly diagnosed essential thrombocythemia or patients whose essential thrombocythemia failed to respond to hydroxyurea and who still have palpable disease or treatable symptoms are eligible to enroll in the trial, she expands. Moreover, the major primary end point of the trial is durability of response. The investigators will measure hematologic response, such as platelet count remission. Key secondary end points will include hematologic response, control of spleen, and occurrence of thromboembolic events, she adds.

Interestingly, patients pretreated with an interferon are not eligible for the current study, but future amendments to the study will include mandatory measurement of neutralizing antibodies. Upon this amendment, patients who carry no neutralizing antibodies will be eligible regardless of previous interferon exposure, Masarova concludes.