Ropeginterferon Alfa-2b (P1101) vs. Anagrelide in Essential Thrombocythemia Patients With Hydroxyurea Resistance or Intolerance

Summary

This is a Phase 3 open-label, multicenter, randomized, active-controlled study designed to compare the efficacy and safety and tolerability of P1101 compared with ANA after 12 months of treatment as second-line therapy for subjects with ET who have had a suboptimal or failed response to HU.

Timeline

Start

2020-08-25

Primary completion

2024-11-12

Completion

2029-08-31

Outcome

Met primary endpoint

paper The trial met its primary endpoint PMID 41193116 ↗

paper This difference (36·5%, 95% CI 25·4-47·7) was significant (p=0·0001). PMID 41193116 ↗

release “Data showed that ropeginterferon alfa-2b achieved statistically superior responses, with 43% of patients demonstrating durable responses at months 9 and 12” pharmaessentia.com ↗

Publications

• Mesa R, Gill H, Zhang L, Jin J, Kirito K, Komatsu N, Qin A, Xiao Z, Tashi T, Shimoda K, Ohishi K, Chen S, Zuo X, Shirane S, Hu Y, Zhang S, Wang Y, Takenaka K, Ichii M, Xu N, Shih LY, Lim KH, Lee SE, Bae SH, Teo WZY, Maze D, Oh ST, Bose P, Sato T, Zagrijtschuk O, Lin S, Shih WJ, Mascarenhas J, Masarova L; SURPASS-ET Study Group. Ropeginterferon alfa-2b in hydroxyurea-intolerant or hydroxyurea-refractory essential thrombocythaemia (SURPASS ET): a multicentre, open-label, randomised, active-controlled, phase 3 study. Lancet Haematol. 2025 Nov;12(11):e862-e875. doi: 10.1016/S2352-3026(25)00264-9.
• Verstovsek S, Komatsu N, Gill H, Jin J, Lee SE, Hou HA, Sato T, Qin A, Urbanski R, Shih W, Zagrijtschuk O, Zimmerman C, Mesa RA. SURPASS-ET: phase III study of ropeginterferon alfa-2b versus anagrelide as second-line therapy in essential thrombocythemia. Future Oncol. 2022 Sep;18(27):2999-3009. doi: 10.2217/fon-2022-0596. Epub 2022 Aug 4.

Drugs

Evaluation	Drug	Modality	Dose	Route
Comparator	Anagrelide	Small molecule	0.5 mg	Oral
Subject	Ropeginterferon alfa-2b	Protein / enzyme biologic	500 ug	Subcutaneous

Indications