Ropeginterferon alfa-2b in hydroxyurea-intolerant or hydroxyurea-refractory essential thrombocythaemia (SURPASS ET):...

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• High-risk essential thrombocythaemia (ET) initial treatment is hydroxyurea, but resistance or intolerance affects one-third of patients.
• Anagrelide is a standard second-line therapy for ET.
• Ropeginterferon alfa-2b, a novel interferon therapy, is approved for polycythaemia vera.

Purpose of the Study:

• To evaluate the efficacy and safety of ropeginterferon alfa-2b versus anagrelide.
• To assess ropeginterferon alfa-2b as a second-line treatment in hydroxyurea-intolerant or resistant ET patients with leukocytosis.

Main Methods:

• Phase 3, open-label, randomized, active-controlled SURPASS ET trial.
• 174 patients with high-risk ET, leukocytosis, and hydroxyurea intolerance/resistance were randomized (1:1) to ropeginterferon alfa-2b or anagrelide.
• Primary endpoint: response rate at 9 and 12 months per modified European LeukemiaNet (ELN) criteria.

Main Results:

• The trial met its primary endpoint: 43% response with ropeginterferon alfa-2b vs. 6% with anagrelide (p=0.0001).
• Grade 3+ adverse events were lower with ropeginterferon alfa-2b (23%) compared to anagrelide (34%).
• Serious adverse events were also lower with ropeginterferon alfa-2b (14%) vs. anagrelide (30%), with no cerebral infarction events.

Conclusions:

• Ropeginterferon alfa-2b demonstrated significantly higher efficacy than anagrelide in this patient population.
• Ropeginterferon alfa-2b showed a favorable safety profile compared to anagrelide.
• Ropeginterferon alfa-2b is a potential second-line treatment option for essential thrombocythaemia with leukocytosis.