Regulatory Pathway Opens for Ropeginterferon alfa-2b in Essential Thrombocytopenia

Durable hematologic responses were observed in patients with essential thrombocytopenia (ET) treated with ropeginterferon alfa-2b-njft (P1101) in the phase 3 SURPASS-ET clinical trial. With this result, the trial has met its primary endpoint, according to an announcement from PharmaEssentia Corporation, developer of ropeginterferon alfa-2b-njft.

“Ropeginterferon is approved for polcythemia vera patients but not for ET. There is lack of second-line options for ET patients with clearly unmet medical needs like their risks of vascular events, such as heart attacks or strokes, and disease progression. This trial assessed efficacy of ropeginterferon against standard of care anagrelide in a randomized phase 3 study,” Lucia Masarova, MD told Heme Today.

Topline results from the study also demonstrated a trend toward reaching the secondary endpoint of decrease in JAK2 V617F allelic burden. Collectively, the findings have led PharmaEssentia to plan the submission of an application to expand the FDA label of ropeginterferon alfa-2b-njft to include treatment of ET. The submission is expected by the end of 2025.

SURPASS-ET compared second-line treatment with ropeginterferon alfa-2b with anagrelide in patients with ET over a 12-month period. Of the 174 patients enrolled, 91 were randomly assigned to the ropeginterferon alfa-2b arm, and 83 patients received anagrelide. Overall, 42.9% of patients in the ropeginterferon alfa-2b arm achieved durable response at months 9 and 12 compared with only 6.0% of those in the control arm (P =.0001). Moreover, fewer serious treatment-related adverse events were observed with the experimental agent (2.2%) compared with the control (10%), underscoring the manageability of its safety profile.

In the study, JAK2 V617F allelic burden was assessed at baseline and at the 12-month mark. In comparison with the baseline assessment, patients treated with ropeginterferon alfa-2b showed an 8.4% decrease in JAK2 V617F allelic burden versus a 2.4% decrease in the anagrelide arm. Based on this finding, investigators believe that ropeginterferon alfa-2b may address underlying disease more effectively than anagrelide.

“We will await details on vascular events and other important endpoints, such as controls of spleen or symptoms, but seeing much positive clinical responses is already very exciting and clinically relevant. It means we can provide better disease control to these patients, said Dr. Masarova, assistant professor, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.

Specifically, detailed findings from SURPASS-ET including pharmacokinetic and biomarker data will be presented in the future. PharmaEssentia Corporation is also investigating ropeginterferon alfa-2b in the ongoing phase 2b EXCEED-ET clinical trial (NCT05482971).

“The data highlight the broad potential to apply our innovative monopegylated, long-acting interferon technology as a significant step forward for treating ET, and potentially other myeloproliferative neoplasms, with non-chemotherapy treatments. We plan to leverage these data to expand the existing P1101 product label and further expand the reach of P1101 to address this growing global unmet medical need,” stated Ko-Chung Lin, PhD, founder and CEO of PharmaEssentia, in a press release.

Reference

PharmaEssentia announces positive topline phase 3 data from SURPASS-ET study evaluating ropeginterferon alfa-2b-njft (P1101) for essential thrombocythemia. News release. PharmaEssentia Corporation. January 6, 2024. Accessed January 6, 2024.  https://bwnews.pr/4h0SmjQ