Aptevo Therapeutics Inc.

Business overview

• Clinical-stage biotechnology company developing immunotherapy candidates for cancer.
• Owns two platform technologies for rational design of precision immune modulatory proteins:
  • ADAPTIR
  • ADAPTIR-FLEX
• Pipeline totals eight molecules: two clinical candidates and six preclinical candidates.
• Platform approach includes monospecific, bispecific, and multi-specific proteins designed to engage T cells and NK cells and target tumors with controlled safety and efficacy profiles.

Lead clinical candidates

• Mipletamig

  • Mechanism: CD123 x CD3 T cell engager (bispecific ADAPTIR) that redirects T cells to CD123-expressing leukemia cells.
  • Indication: Frontline acute myeloid leukemia (AML) in combination with venetoclax + azacitidine (RAINIER program); Phase 1b/2 dose optimization in frontline patients not fit for intensive chemotherapy.
  • Status: Active in the RAINIER trial with multiple dose levels.
  • Design: Engineered CRIS-7 CD3 binding domain to reduce cytokine release syndrome (CRS).
  • Regulatory: FDA Orphan Drug Designation for AML (granted Nov 26, 2019).

• ALG.APV-527

  • Mechanism: Bispecific ADAPTIR targeting 4-1BB (CD137) and 5T4 to stimulate tumor-specific T and NK cell activity in the tumor microenvironment.
  • Indication: Solid tumors expressing 5T4 (potential across multiple tumor types, including breast, cervical, NSCLC, prostate, renal, gastric/GEJ, colorectal, bladder).
  • Status: Phase 1 dose-escalation trial completed across up to six dose levels; next steps under evaluation with Alligator Bioscience.
  • Safety/biomarkers: Detectable ALG.APV-527 in sera; no severe liver toxicity observed in dose-escalation data; 58% best response of stable disease in efficacy-evaluable patients.
  • Collaboration: Co-developed with Alligator Bioscience AB; joint ownership of relevant IP; revenue-sharing and opt-out provisions in the collaboration agreement.

Other pipeline (preclinical)

• APVO603: Dual agonist targeting 4-1BB and OX40.
• APVO442: PSMA-targeted bispecific for prostate cancer.
• APVO711: Bispecific checkpoint/inflammatory modality combining PD-L1 and CD40.
• APVO455: Nectin-4 x CD3 bispecific.
• APVO451: Nectin-4 x CD40 x CD3 trispecific (ADAPTIR-FLEX trispecific).
• APVO452: PSMA x CD40 x CD3 trispecific.
• Additional preclinical programs within the ADAPTIR/ADAPTIR-FLEX pipeline.

Platform technologies

• ADAPTIR: Monospecific and bispecific protein therapeutics with antibody-like properties. Fc region can be modified to alter effector function and half-life; supports redirected T cell cytotoxicity with tumor-targeting domains.
• ADAPTIR-FLEX: Heterodimer platform enabling up to four-target binding and adjustable valency; supports mono-, bi-, and trispecific formats to achieve varied signaling and potency profiles.
• IP and licenses:
  • Company-owned ADAPTIR and ADAPTIR-FLEX IP.
  • Non-exclusive licenses for CHO cell lines/vectors (Lonza) and OmniAb transgenic rodent technology (OMT).
  • Core portfolio includes mipletamig, ALG.APV-527, and the preclinical programs covered by owned or licensed IP.
• Collaboration with Alligator Bioscience:
  • ALG.APV-527 developed under a 2017 collaboration; parties jointly own IP generated in development activities, subject to opt-out rights and revenue-sharing terms.
  • Agreement establishes a framework for development and potential future commercialization, including mutual rights and wind-down provisions.

Financial and funding snapshot (as of 12/31/2025)

• Employees: 33 full-time and 3 contract personnel (total 36).
• Cash and equivalents: $21.6 million.
• Net loss: $26.0 million for the year ended December 31, 2025.
• Accumulated deficit: $275.1 million.
• Stockholders’ equity: $17.4 million.
• Revenue: No product revenues reported; future revenue could come from milestone payments or collaborations, including potential payments related to IXINITY (development and commercialization of IXINITY are no longer controlled by Aptevo).
• Financing facilities:
  • Standby Equity Purchase Agreements (SEPAs) with Yorkville:
    • First SEPA: up to $25.0 million over 36 months
    • Second SEPA: up to $60.0 million over 36 months
    • Combined remaining capacity: $67.5 million
• Nasdaq and corporate actions:
  • Regained listing compliance after a June 2025 equity raise of about $15.9 million.
  • Executed a 1-for-18 reverse stock split on 12/29/2025.
  • Stock price cited at $4.49 per share as of 3/23/2026.
  • Company governance includes a Rights Agreement with Broadridge (extended to 2026) and charter/bylaw provisions under Delaware law.

Corporate and operations

• Headquarters: Seattle, Washington.
• Facilities: Lease for the Seattle headquarters (~48,000 sq ft) expires April 2030.
• Management transition: Marvin L. White to transition to Executive Chair of the Board effective April 1, 2026; Jeffrey G. Lamothe to become President and Chief Executive Officer.
• Regulatory environment: Company discusses potential regulatory pathways (e.g., BLA), orphan designation implications, and typical oncology/biotech regulatory risks.

Key takeaways

• Aptevo is a small, clinical-stage biotech focused on cancer immunotherapy built on the ADAPTIR and ADAPTIR-FLEX platforms.
• Near-term clinical focus is mipletamig in frontline AML (RAINIER) and ALG.APV-527 in 5T4-expressing solid tumors (developed with Alligator).
• The company has limited current revenue, ongoing operating losses, and relies on external financing (SEPAs, equity raises) to fund development.
• Operations are centralized in a single Seattle facility, and the company is undergoing a leadership transition while pursuing partnerships to advance its pipeline.