AstraZeneca PLC / Caelum Biosciences

Light chain (AL) amyloidosis

6K US cases/yr · $3.5B Global AL + ATTR amyloidosis drug sales 2021 (USD MM, including Vyndaqel/Vyndamax) · 30 Percent of newly diagnosed AL amyloidosis patients dying within 12 months (%)

Disease Overview

Light chain (AL) amyloidosis is a rare, life-threatening hematologic disorder in which a clonal plasma cell dyscrasia produces misfolded immunoglobulin light chains that aggregate as amyloid fibrils, depositing in vital organs (heart, kidney, liver, peripheral nerves, GI tract) and causing progressive organ failure. US incidence is approximately 4,500-5,500 new cases annually (Boston Amyloidosis Center / Mayo Clinic registry estimates), with a US prevalence of roughly 30,000-45,000 living patients given median overall survival of 4-6 years and ~30% of newly diagnosed patients dying within the first 12 months due to advanced cardiac involvement. Cardiac AL amyloidosis is the dominant prognostic driver: Mayo Stage IV disease (high NT-proBNP and troponin) carries median OS under 12 months. Standard-of-care therapy targets the clonal plasma cells (CyBorD chemotherapy and, since the Jan 2021 ANDROMEDA-based approval, Darzalex Faspro + CyBorD), but no approved agent directly targets and clears existing amyloid fibrils — an unmet need particularly acute in patients with high cardiac amyloid burden where rapid organ recovery is essential. AL amyloidosis is distinct from ATTR amyloidosis (transthyretin-driven), where Vyndaqel (tafamidis) and Onpattro (patisiran) are approved.

Competitive Landscape

At deal date Oct 2021, no fibril-directed antibody had been approved for AL amyloidosis; the field had been defined by two prior Phase 3 failures — NEOD001 (Prothena, Phase 3 PRONTO + Phase 2b VITAL discontinued April 2018 for futility) and birtamimab (Prothena, Phase 3 VITAL halted by IDMC for futility 2018, repositioned for Mayo Stage IV). CAEL-101 (anselamimab) was an IgG1 chimeric monoclonal antibody licensed from Columbia University (Wall/Solomon group) that binds a cryptic epitope on misfolded kappa and lambda light chain fibrils to mediate immune-mediated clearance, distinguishing it from upstream plasma cell-directed agents. Active competitors in plasma cell suppression: Darzalex Faspro (daratumumab + hyaluronidase, Janssen, FDA-approved Jan 2021 with CyBorD on the ANDROMEDA trial) was first-line backbone; Empliciti (elotuzumab, BMS), Sarclisa (isatuximab, Sanofi), and Velcade (bortezomib, Takeda) provided multi-line plasma-cell options. Direct fibril-clearing competitors at deal date: birtamimab (Prothena, Phase 3 AFFIRM-AL ongoing in Mayo Stage IV) and AT-02 / ALXN-2220 (Eidos/BridgeBio in ATTR, separate target). Caelum's CAEL-101 had Phase 2 data showing organ response in cardiac and renal AL, supporting two Phase 3 trials (CARES-1 and CARES-2) launched 2021 in newly diagnosed Mayo Stage IIIa/IIIb patients in combination with anti-plasma-cell SoC.