Bristol-Myers Squibb Company / Orbital Therapeutics, Inc.

B-cell mediated autoimmune diseases (initial)

2.5M US cases/yr · $45.0B US B-cell autoimmune biologics market · >90% Drug-free remission rates in early CD19 CAR-T autoimmune studies

Disease Overview

B-cell mediated autoimmune diseases form a spectrum of conditions including systemic lupus erythematosus (SLE), lupus nephritis, ANCA-associated vasculitis, myasthenia gravis, idiopathic inflammatory myopathies, pemphigus, and systemic sclerosis. The unifying pathophysiology involves autoreactive B cells producing pathogenic autoantibodies, presenting antigens, and driving T-cell dysfunction. US prevalence aggregates to over 2.5 million patients, with approximately 200,000-300,000 SLE patients, 65,000 myasthenia gravis cases, and 20,000-40,000 ANCA vasculitis patients. CD19 CAR-T therapy has transformed the autoimmune treatment paradigm following 2022-2024 single-institution data showing drug-free remissions in lupus, myositis, and systemic sclerosis patients after a single infusion. However, ex vivo CAR-T delivery faces manufacturing complexity, lymphodepletion requirements, and access barriers. In vivo CAR-T generation using mRNA/LNP delivery represents the next frontier: eliminating apheresis and manufacturing while potentially enabling repeat dosing. Orbital Therapeutics' OTX-201 uses circular RNA (circRNA) - a more stable RNA form than linear mRNA - encoding anti-CD19 CAR and delivered via LNP for in vivo T-cell transduction. Clinical validation is still pending but the approach could democratize CAR-T benefits across autoimmune populations.

Competitive Landscape

In vivo cell therapy landscape is emerging with multiple technology vectors competing for the autoimmune CAR-T opportunity. Linear mRNA/LNP CAR delivery is being pursued by Capstan Therapeutics (acquired by AbbVie for $2.1B June 2025, lead program CPTX2309 anti-CD19 mRNA LNP for autoimmune), Moderna through in vivo platform collaborations, and Umoja Biopharma's VivoVec lentiviral in vivo CAR-T approach. Ex vivo CAR-T autoimmune competitors remain central to the field: Kyverna Therapeutics' KYV-101 (anti-CD19 CAR-T, multiple Phase 2 autoimmune studies), Cabaletta Bio's CABA-201 (CD19 CAR-T, Phase 2 studies across SLE, myositis, systemic sclerosis, and myasthenia gravis), and Novartis's rapcabtagene autoleucel/YTB323 (anti-CD19 CAR-T across autoimmune indications). Allogeneic CAR-T competitors include Allogene Therapeutics' ALLO-329 and Caribou Biosciences' CB-010. Bispecific T-cell engagers for autoimmune include Cullinan Oncology's CLN-978 (CD3xCD19), with additional exploration of Amgen's blinatumomab/Blincyto and Roche's mosunetuzumab/Lunsumio. Orbital Therapeutics' circRNA platform differentiation sits on two axes: circular RNA offers greater stability and longer sustained protein expression than linear mRNA, and the integrated platform combines AI-driven design for optimized LNP tropism and CAR architecture. BMS's acquisition expands its in vivo cell therapy position beyond Abecma (idecabtagene vicleucel) and Breyanzi (lisocabtagene maraleucel) ex vivo CAR-T franchises facing competitive and reimbursement pressure in multiple myeloma and large B-cell lymphoma.