Apogee Therapeutics

Company at a glance

Clinical-stage biotechnology company focused on optimized antibody biologics for inflammatory and immunology (I&I) diseases.
Goal: improved efficacy with less frequent dosing through engineered, extended half-life antibodies.
Target indications: atopic dermatitis (AD), asthma, eosinophilic esophagitis (EoE), chronic obstructive pulmonary disease (COPD), and other I&I conditions.
Core approach: target validated pathways (IL-13, IL-4Rα, IL-13/IL-4 axis, OX40L, TSLP) with half-life–extended antibodies to support less frequent maintenance dosing.

Pipeline and programs

All programs use half-life extension variants (YTE and LS) to enhance FcRn recycling and prolong systemic exposure. Delivery is by subcutaneous injection with plans for pre-filled syringes or autoinjectors.

Zumilokibart (APG777)
- Target: IL-13
- Format: Subcutaneous, extended half-life monoclonal antibody
- Status highlights:
  - Phase 1 in healthy volunteers (Aug 2023): 40 healthy adults; long PK half-life (up to 77 days) and durable PD effects.
  - APEX Phase 2 in AD:
    - Part A topline (Jul 2025): strong efficacy versus placebo across EASI, EASI-75, vIGA 0/1, and Itch NRS; safety profile consistent with class.
    - Part A maintenance data planned for March 2026.
    - Part B dosed Feb 2025; topline data expected Q2 2026; enrollment exceeded target (planned 337–347 across Part B).
  - Development path includes potential Phase 3 in AD beginning in 2026 and a potential launch around 2029.
APG279 (Zumilokibart + APG990, coformulated concept)
- Partnered with APG990 (anti-OX40L)
- Status highlights:
  - Phase 1b ongoing versus DUPIXENT in AD; enrollment increased from ~50 to ~80 patients due to strong demand; readout expected H2 2026.
  - APG990 early human PK: half-life ~60 days; favorable safety and tolerability.
APG273 (Zumilokibart + APG333)
- Partnered with APG333 (anti-TSLP)
- Status highlights:
  - APG333 Phase 1 in healthy volunteers (Dec 2024); interim safety/PK/PD (Nov 2025) showed half-life ~55 days and durable biomarker suppression (eosinophils, IL-5) out to 6 months.
  - APG273 development plans announced for 2026 to support asthma and COPD programs.
APG808 (anti-IL-4Rα)
- Target: IL-4Rα
- Status highlights:
  - Phase 1 (healthy volunteers and asthma cohorts) initiated in 2024.
  - Interim Phase 1b data in mild-to-moderate asthma (May 2025): rapid FeNO suppression, pSTAT6 reduction, and TARC changes.
  - Half-life ~55 days, supporting every-2–3-month maintenance dosing potential.

Mechanisms and program advantages

IL-13 axis: APG777 and combos (APG279, APG273) aim to intensify Type 2 inflammation control.
Combination approaches:
- APG279: IL-13 plus broader Type 1–3 modulation via OX40L inhibition.
- APG273: IL-13 plus TSLP inhibition for broader airway and immune modulation.
IL-4Rα axis: APG808 blocks IL-4/IL-13 signaling via IL-4Rα to affect upstream pathway activity.
Emphasis on extended half-life (YTE/LS) to enable maintenance dosing intervals from quarterly to semi-annual in some indications.

Manufacturing, partnerships, and supply chain

Paragon collaboration
- Antibody discovery and option agreements for IL-13, IL-4Rα, OX40L, and TSLP.
- Exclusive worldwide license options per target upon exercise, with upfronts, milestone payments, and low-single-digit royalties to Paragon.
- Active licenses for IL-13, IL-4Rα, OX40L, and TSLP; rights permit development, manufacture, and commercialization; exclusivity and right of first refusal for related multispecific antibodies.
WuXi Biologics
- Master services agreement for development and GMP manufacturing of zumilokibart, APG990, APG333, APG808, and potential future candidates.
- Cell line license for manufacturing and ongoing batch testing and quality control support.
Samsung Biologics
- Master services agreement and an initial project-specific agreement for clinical batch manufacturing of zumilokibart, with potential future commercial supply arrangements.
Additional supply chain
- Multiple cell-line and process development relationships to support scale-up and manufacturing readiness, providing redundancy for clinical supply.

Intellectual property

IL-13 program: eight patent families covering antibodies (including zumilokibart), formulations, and uses; expiries generally mid-2040s absent extensions.
OX40L program: four patent families for anti-OX40L antibodies (APG990) and related compositions; expiries in the 2040s.
TSLP program: Paragon-licensed families plus additional global filings; expiries in the mid-2040s.
IL-4Rα program: four patent families covering APG808 and related combinations; expiries in the mid-2040s.
Combination/multispecific programs: seven patent families covering co-formulations, combinations, and methods; expiries around 2045–2046.
Strategy: broad patent coverage for antibodies, formulations, methods of use, and combinations, supported by trade secrets and ongoing prosecution.

People and operations

261 full-time employees as of December 31, 2025.
57 employees hold Ph.D. or M.D. degrees.

Financial snapshot

Net loss: $255.8 million for the year ended December 31, 2025; $182.1 million for 2024.
Accumulated deficit: $561.8 million as of December 31, 2025.
Cash, cash equivalents, and marketable securities expected to fund operating expenses into the second half of 2028.
The company identifies a need for substantial additional funding to continue advancing programs.

Market and development context

Primary focus on AD and related Type 2 inflammatory diseases, with potential expansion into asthma, EoE, COPD, and other I&I indications.
Competitive field includes approved and development-stage biologics targeting IL-4Rα, IL-13, the IL-13/IL-4 axis, OX40L, and TSLP; Apogee seeks differentiation through extended dosing intervals and combination approaches to broaden mechanism coverage.
Market feedback from healthcare professionals and patients indicates strong interest in maintenance dosing options every three to six months to improve adherence and convenience.

Apogee Therapeutics, Inc.

10-K / March 2, 2026