Sanofi SA / Chia Tai Tianqing Pharmaceutical Group (subsidiary of Sino Biopharmaceutical Limited)

Chronic graft-versus-host disease (cGVHD)

3K US cases/yr · $1.4B Global cGVHD therapeutic market 2024 (Incyte, Sanofi 10-K product revenue)

Disease Overview

Chronic graft-versus-host disease (cGVHD) is a late, multisystem immune-mediated complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in which donor-derived T cells and B cells mount persistent alloimmune and autoimmune attack against recipient tissues. Per the NIH National Cancer Institute and Center for International Blood and Marrow Transplant Research (CIBMTR), cGVHD develops in roughly 30-50% of allo-HSCT recipients and represents the leading cause of non-relapse mortality and morbidity beyond day +100 post-transplant. Clinical phenotypes include sclerotic and lichenoid skin involvement, sicca-like ocular and oral disease, bronchiolitis obliterans syndrome (BOS), hepatic cholestasis, fasciitis, joint contractures, and gastrointestinal dysmotility. NIH Consensus Criteria (2014 revision) define diagnosis and severity grading (mild/moderate/severe) based on organ involvement and performance status. U.S. incidence tracks annual allo-HSCT volumes - approximately 9,000 adult allo-HSCTs per year per CIBMTR - with cGVHD affecting 3,000-5,000 patients annually and a prevalent population of roughly 14,000-20,000 given chronicity. Historical first-line therapy is systemic corticosteroids; however, ~50% of patients require second-line therapy for steroid-refractory or steroid-dependent disease, which until recently had limited options. The pathophysiology involves thymic injury, loss of T-regulatory cell tolerance, B-cell dysregulation with BAFF upregulation, and profibrotic cytokine signaling via ROCK, JAK-STAT, and TGF-beta pathways.

Competitive Landscape

The steroid-refractory cGVHD landscape is segmented by MOA with three post-steroid approved agents and an emerging pipeline. JAK inhibitors: Jakafi (ruxolitinib, Incyte/Novartis) is FDA-approved for steroid-refractory cGVHD (second-line) based on the REACH3 Phase 3, with cGVHD contributing meaningfully to Jakafi's $2.8B 2024 U.S. net revenue per Incyte 10-K; Jakafi is also approved for steroid-refractory aGVHD. ROCK2 inhibitors: Rezurock (belumosudil, Sanofi) was approved 2021 for 3L+ cGVHD based on ROCKstar Phase 2; 2024 revenue ~$425M per Sanofi disclosure. BTK inhibitors: Imbruvica (ibrutinib, AbbVie/J&J) was approved 2017 for 2L+ cGVHD but saw its FDA approval withdrawn in 2024 after iNTEGRATE Phase 3 failed. JAK/ROCK dual inhibitors (emerging): rovadicitinib (anxu, CTTQ/Sanofi - the Sanofi license target) is a first-in-class oral JAK/ROCK dual inhibitor already approved in China for myelofibrosis; Sanofi's ex-China thesis is that simultaneous JAK-STAT and ROCK-pathway inhibition combines the inflammatory control of Jakafi with the profibrotic disruption of Rezurock in a single oral agent. Other pipeline: MaaT Pharma's MaaT013 fecal microbiota transfer (aGVHD), Equillium's itolizumab (anti-CD6, Phase 3 aGVHD), and multiple anti-CD20 and CAR-Treg programs.