Eli Lilly and Company / Sigilon Therapeutics Inc.

Type 1 diabetes (encapsulated stem cell-derived islet cell therapy)

2M US cases/yr · $18.0B US insulin + CGM market 2023 (USD MM, T1D+T2D combined, T1D addressable subset) · 309 Total Lilly-Sigilon deal size (USD MM, ~$34.6M upfront cash + up to $275M CVR at $111.64/sh)

Disease Overview

Type 1 diabetes (T1D) affects approximately 2 million Americans (CDC National Diabetes Statistics Report 2022) with annual incidence of ~64,000 new diagnoses across pediatric and adult onset. Standard of care remains multiple-daily-injection or pump-delivered insulin augmented by continuous glucose monitoring; cumulative 2023 US insulin and CGM market value exceeds $18 billion. The unmet clinical need addressed by encapsulated islet-cell therapy is severe hypoglycemia unawareness and glycemic instability in the ~60,000-patient subpopulation with impaired hypoglycemic awareness, where CGM alone is insufficient. Sigilon's lead asset SIG-002 combines Eli Lilly-partnered stem-cell-derived insulin-producing cells inside Sigilon's proprietary Afibromer hydrogel encapsulation designed to mask the graft from immune rejection without systemic immunosuppression. Sigilon had been in a research collaboration with Lilly since April 2018 covering $63M upfront and up to $473M in milestones; the 2023 acquisition consolidates ownership of SIG-002 within Lilly's expanding diabetes cell-therapy footprint. Sigilon shares traded at $0.73 pre-deal, and the $14.92 cash plus $111.64 CVR offered an 230% premium to unaffected share price.

Competitive Landscape

The encapsulated-islet and stem-cell-derived cell therapy landscape for T1D is tightly contested. Vertex Pharmaceuticals leads clinical development with VX-880 (now zimislecel, Phase 1/2/3 FORWARD, uses chronic immunosuppression) and VX-264 (device-encapsulated version, Phase 1/2) following the ViaCyte acquisition September 2022 ($320M) and Semma acquisition 2019 ($950M). Sana Biotechnology's UP421 is an allogeneic hypoimmune gene-edited islet cell candidate; Phase 1 initial data January 2025 showed survival without immunosuppression. CRISPR Therapeutics has VCTX211 and VCTX212 hypoimmune cell programs plus the March 2023 non-exclusive Vertex license. Sernova's Cell Pouch System is a device-encapsulated islet approach in Phase 1/2 with U Chicago. Beta-O2 Technologies' βAir device is early-stage. Defymed's MailPan encapsulation device. Broader diabetes portfolio context: Novo Nordisk, Sanofi and Lilly dominate injectable insulin; Lilly's own Tirzepatide (Mounjaro/Zepbound) and investigational retatrutide drive the incretin franchise, making Lilly diabetes-strategic across small molecule, peptide and cell therapy. Sigilon's Afibromer represents the hydrogel-encapsulation variant of the broader immunoevasion problem that Vertex, Sana and CRISPR address via gene editing or device engineering.