Sanofi SA / TargeGen, Inc.

Myelofibrosis

1K US cases/yr

Disease Overview

Myelofibrosis is a Philadelphia-negative myeloproliferative neoplasm marked by progressive bone marrow fibrosis, splenomegaly, anemia, and constitutional symptoms; ~50% of patients carry a JAK2 V617F mutation. Median survival from diagnosis is roughly 6 years and there is no curative therapy outside allogeneic stem-cell transplant in eligible patients.

Competitive Landscape

In June 2010 myelofibrosis had no FDA-approved targeted therapy. Standard of care was supportive — hydroxyurea, transfusions, anagrelide, splenectomy/splenic radiation — with allogeneic stem-cell transplant for the small fit-and-young subset. The clinical-development field was dominated by Incyte's INCB018424 (later Jakafi/ruxolitinib, FDA-approved Nov 2011 under the Novartis ex-US partnership), with TargeGen's TG101348 (fedratinib) as the most advanced challenger; trial enrollment in TG101348's Phase 1/2 was complete at deal time. Other JAK2 inhibitors in development included CYT387 (momelotinib, YM Biosciences/Gilead), SB1518 (pacritinib, S*Bio/CTI BioPharma), and lestaurtinib (Cephalon). Sanofi paid $75M upfront/up to $485M total to acquire a near-Phase-3-ready JAK2 inhibitor and add a hematology franchise alongside Mozobil/Eloxatin. The deal failed strategically — Sanofi placed JAKARTA on FDA hold for Wernicke's encephalopathy in 2013 and discontinued — but the asset was salvaged by Impact Biomedicines and approved as Inrebic in 2019 after Celgene's $1.1B Impact buyout.