The RESPONSE trial evaluated JAKAVI in patients with inadequately controlled PV^1,2

The RESPONSE trial was a randomised, open-label, active-controlled Phase III trial^1,2

• RESPONSE evaluated the efficacy and safety of JAKAVI in PV patients who had inadequate response to or unacceptable side effects from HU¹
• Eligibility criteria included all of the following: resistance to or intolerance of HU (based on modified ELN criteria), phlebotomy dependence, splenomegaly, and haematocrit control (40%-45%) within 14 days prior to randomisation¹

Patients were stratified by HU intolerance/resistance and randomised to JAKAVI (starting dose of 10 mg BID individually titrated up to a maximum of 25 mg BID) or investigator-selected BAT as monotherapy (HU, interferon/pegylated interferon, anagrelide, pipobroman, immunomodulatory drugs [IMIDs], or observation). Patients were to receive low-dose aspirin unless medically contraindicated.^1,2 The data cutoff for the primary analysis occurred when all patients reached Week 48 or discontinued therapy.¹

86% of patients in the BAT arm had crossed over to the JAKAVI arm by Week 48³

Endpoints in the RESPONSE trial assessed haematologic, symptomatic, and safety parameters^1,2

Primary endpoint

Haematocrit control was defined as the absence of phlebotomy eligibility from Week 8 to Week 32, with no more than one post-randomisation phlebotomy allowed prior to Week 8. Phlebotomy eligibility was defined as haematocrit >45% and ≥3% higher than baseline or >48%, whichever was lower.^1,2 Spleen volume was assessed by MRI or CT.¹

Key secondary endpoints

• Durability of primary response at Week 48^1,2
• Complete haematologic remission at Week 32^1,2

Other endpoints

• Duration of response¹
• Symptom reduction¹
• Safety¹

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