Korsana Biosciences (KRSA) 3rd Annual Guggenheim Healthcare Innovation Conference summary

Market and rationale

• Alzheimer's treatment is at an inflection point: two approved disease-modifying therapies validate the biology, while brain shuttles may further improve therapeutic profiles.

• Trontinemab phase I/II findings included greater brain delivery, faster and deeper plaque clearance, and lower ARIA rates than unshuttled antibodies; IV dosing, infusion reactions and reticulocyte depletion remain improvement opportunities.

• Approved Alzheimer's therapies were annualizing over $1 billion a few years after launch; management sees substantial headroom and cites six to seven times the patient population of multiple sclerosis.

• An at-home auto-injector is the goal at launch, alongside fast activity and good tolerability.

KRSA-028 profile

• Lead program KRSA-028 is a shuttled anti-amyloid antibody targeting pyroglutamate-modified amyloid forms enriched in plaques, with the aim of selective, rapid plaque clearance.

• Fc engineering is designed to extend half-life and improve peripheral exposure while preserving phagocytosis and eliminating CDC and ADCC; management calls this selective effector function modulation.

• Non-human-primate data showed longer exposure, reticulocyte sparing and preserved phagocytosis; head-to-head results versus trontinemab were described as strongly differentiated.

• Better exposure is intended to support trontinemab-like exposure with a lower, less frequent dose and a low-volume monthly subcutaneous injection; faster plaque clearance remains uncertain.

• The antibody was designed for subcutaneous developability, with clinical development set to start using subcutaneous injection.

Clinical development and milestones

• Planned phase I/II has three parts: single-ascending-dose study in healthy volunteers in Australia and New Zealand, multiple-ascending-dose study in patients, then expansion cohorts to characterize safety and support a potential phase III path.

• CTA filing for the SAD is planned by end-2026, followed by a U.S. IND in early 2027 for the MAD; SAD data are expected in mid-2027.

• SAD readouts will assess subcutaneous exposure, half-life, safety including CBCs, and CSF levels as an indicator of brain delivery; fuller activity assessment requires the MAD.

• Interim proof of concept may come from one or two MAD cohorts; PET plaque clearance at a trontinemab-like dose response would support confidence in comparable or better activity.

• Expansion cohorts are intended to provide enough safety data for global regulators to consider a direct phase III; Roche used cohorts of up to about 75 patients at its top two doses as precedent.