[{"id":"per2-svr","name":"Spleen volume reduction >=35% at Week 24","type":"CO-PRIMARY","unit":"%","p_value":"0.001","results":[{"n":"16/74 evaluable","arm":"per2-200bid","label":"22% (200mg BID)","value":22},{"n":"2/72 evaluable","arm":"per2-bat","label":"3% (BAT)","value":3}],"timepoint":"Week 24","description":"Proportion achieving >=35% spleen volume reduction by MRI. Spleen enlargement is a hallmark of myelofibrosis - shrinking it by 35% represents clinically meaningful response. The key differentiator: these are patients with very low platelets (<100K, approved for <50K) who cannot safely receive ruxolitinib."},{"id":"per2-tss","name":"Total Symptom Score >=50% reduction at Week 24","type":"CO-PRIMARY","unit":"%","p_value":"0.01","results":[{"n":"24/74","arm":"per2-200bid","label":"32% (200mg BID)","value":32},{"n":"10/72","arm":"per2-bat","label":"14% (BAT)","value":14}],"timepoint":"Week 24","description":"Proportion achieving >=50% reduction in symptom burden (fatigue, night sweats, bone pain, abdominal discomfort, early satiety, itching)."}]

Diarrhea 48% all-grade (4% Gr3). Nausea 32%. Grade 3/4 bleeding 14% (vs 7% BAT). Grade >=3 cardiac events 9% (vs 19% BAT - actually lower). Mortality: 4.7% (200mg BID), 10.6% (400mg QD), 12.2% (BAT). 20% discontinued due to AEs (vs 17% BAT). Thrombocytopenia worsening requiring dose reduction: only 2% in <50K subgroup.

Vonjo has accelerated FDA approval (Feb 2022) based on PERSIST-2. PACIFICA is the confirmatory trial - failure could mean approval withdrawal and Vonjo revenue going to zero. The 29% SVR in <50K patients fills a genuine unmet need. Key investment debate: PACIFICA timing and whether it confirms the benefit.

Only JAK inhibitor that does not worsen thrombocytopenia. Pacritinib inhibits JAK2/IRAK1/CSF1R but has minimal effect on JAK1, reducing myelosuppression. Fills critical unmet need for MF patients with platelets <50K who cannot receive ruxolitinib.