What Affibody does

Affibody AB is a Swedish clinical-stage biotechnology company headquartered in Stockholm, founded in 1998 to develop therapeutics and diagnostics based on its proprietary Affibody molecule platform. Affibody molecules are small protein scaffolds of approximately 6 kDa—significantly smaller than conventional antibodies (~150 kDa)—engineered to bind specific target antigens with high affinity. The company leverages this miniaturization advantage for superior tumor penetration and rapid clearance from circulation, properties well-suited to radioligand therapy where a radioactive payload is delivered directly to cancer cells.

The company's lead clinical asset is ABY-271, a Lutetium-177 (Lu-177)-conjugated Affibody molecule targeting HER2 for the treatment of HER2-positive metastatic breast cancer in patients resistant to conventional HER2 therapies. ABY-271 entered first-in-human Phase 1 dosing in October 2025, and by December 2025 the Trial Review Committee recommended advancement to a second cohort evaluating higher radioactivity levels based on positive safety, tolerability, and biodistribution data showing low uptake in kidneys and critical organs. Beyond HER2, the pipeline extends to PSMA and GPC3-targeted radioligand therapies, and the platform has been applied to non-oncology indications through out-licensing arrangements.

Affibody operates a hybrid business model combining out-licensed partnerships with retained internal clinical development. The company holds an out-licensing agreement with Rallybio for RLYB116 (a complement factor 5 inhibitor that reported positive Phase 1 PK/PD data in February 2026), generating potential milestone and royalty revenue. It has also secured vertical supply chain integration via a Letter of Intent with SHINE Technologies for non-carrier-added Lu-177 to support clinical and potentially commercial supply. The company is funded primarily through a €20 million EIB loan (December 2022, structured in three tranches) and historical venture and bank financing, and has no commercial product revenue at present. Clinical operations span Sweden and Germany.

Name

Affibody

Legal name

Affibody AB

Website

https://affibody.se

Company type

Private

Founded year

1998

Operating status

Operating

Headcount range

51–100 employees

Short description

Affibody is a Swedish clinical-stage biotech developing radioligand therapies using its proprietary ~6 kDa Affibody molecule platform, with lead candidate ABY-271 in Phase 1 trials for HER2-positive metastatic breast cancer and a broader pipeline targeting PSMA and GPC3.

Ownership category

akta.pro rank

Product category

Radiopharmaceuticals

NAICS

Research and Development in Biotechnology (except Nanobiotechnology) (541714), Pharmaceutical and Medicine Manufacturing (3254)

SIC

Pharmaceutical Preparations (2834), Biological Products, (No Disgnostic Substances) (2836), In Vitro & In Vivo Diagnostic Substances (2835)

akta.pro primary industry

Antibody Discovery & Engineering Platforms (display tech, bispecifics, Fc engineering) (HLAAAIAB)

Keywords

• Radioligand therapy
• Protein scaffolds
• Cancer therapeutics
• Biopharmaceuticals
• Targeted therapy

Headquarters

HQ city

Stockholm

HQ country

Sweden

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Supply Chain, Marketing or Sales

Revenue model

1. Licensing Royalties: Affibody licenses its technology and drug candidates to partners such as Rallybio for RLYB116, generating potential royalty streams from successful commercialization.
2. Pharmaceutical Product Sales (Future): Once clinical candidates receive regulatory approval, the company intends to commercialize radioligand therapies directly or through partnerships, generating product revenue.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

Affibody AB is a Swedish clinical-stage biopharmaceutical company developing radioligand therapies and other protein-based therapeutics for cancer and inflammatory diseases. Its proprietary Affibody molecule platform consists of small (~6 kDa) engineered protein scaffolds that can be conjugated to therapeutic or diagnostic radionuclides (e.g., Lu-177) and targeted to disease-specific biomarkers such as HER2, PSMA, and GPC3. The lead clinical candidate, ABY-271, is a Lu-177-conjugated Affibody molecule in Phase 1 evaluation for HER2-positive metastatic breast cancer. The company also out-licenses its platform (e.g., Rallybio's RLYB116 complement inhibitor).

Product overview

Affibody AB is a Swedish biotech company developing radioligand therapies for cancer treatment. The company's core offering centers on its Affibody molecules platform — small protein scaffolds that can be engineered to target specific biomarkers — which serves as the foundation for its lead product candidate ABY-271. ABY-271 is a HER2-targeted Lu-177-conjugated radioligand therapy in Phase 1 clinical evaluation for HER2-positive metastatic breast cancer, with the company also holding partnerships for therapeutic radionuclide supply (SHINE Technologies) and out-licensing arrangements (Rallybio for complement programs).

Differentiator

Problem solved

Functional benefit

Products and services

• ABY-271
• Affibody Molecules

Quantifiable outcome

• Phase 1 clinical study demonstrated tumor targeting and favorable safety profile with low uptake in kidneys and other critical organs
• +1 more outcomes

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Three partnerships are on record, tiered core and minor.

• SHINE TechnologiescoreTechnology or Integration · 19 February 2026Affibody AB signed a Letter of Intent with SHINE Technologies for the supply of non-carrier-added Lutetium-177 to support the company's radioligand therapy clinical research and development activities. The agreement covers lead program ABY-271 and additional pipeline programs, with potential extension to commercial Lu-177 supply should ABY-271 successfully progress to commercialization.
• RallybiocoreOEM/ Whitelabel/ Licensing Partner · 18 February 2026Affibody's licensee Rallybio announced positive Phase 1 PK/PD clinical study results for RLYB116, a once-weekly subcutaneously injected complement factor 5 inhibitor. Rallybio plans to initiate a Phase 2 clinical study in platelet transfusion refractoriness in H2 2026 with potential topline data in 2027.
• ClarivateminorOthers · 16 June 2025Clarivate released a Companies to Watch report profiling Affibody as one of six radioligand therapy innovators advancing precision oncology, highlighting the company among emerging players alongside Alpha-9 Oncology, Ariceum Therapeutics, Convergent Therapeutics, Perspective Therapeutics, and PRECIRIX.

Scale indicators4 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Novartis: Commercial-stage leader in radioligand therapy with Pluvicto (177Lu-PSMA-617) and Lutathera approved; sets the therapeutic-class standard Affibody's HER2 program must compete against and validates commercial demand for Lu-177-conjugated targeted radioligands.
• Lantheus Holdings: Commercial radiopharmaceutical company with established diagnostic imaging agents and a growing radioligand therapy pipeline; broad incumbent peer providing market and pricing benchmarks for Affibody's imaging and therapy programs.

Direct peers

• Convergent Therapeutics: Clinical-stage radiopharmaceutical company developing PSMA-targeted radioligand therapy for prostate cancer; closely comparable to Affibody as a small-format, target-focused radioligand developer.
• Fusion Pharmaceuticals (AstraZeneca): Clinical-stage radioconjugate developer using targeted alpha therapy; acquired by AstraZeneca for $2.4B, offering a comparable radioligand-therapy peer and exit-precedent for Affibody.
• Ariceum Therapeutics: Developer of radiotheranostics for cancer, including PSMA and somatostatin receptor-targeted agents; comparable European-headquartered radioligand peer profiled alongside Affibody in Clarivate's Companies to Watch.
• RayzeBio (Bristol Myers Squibb): Clinical-stage radiopharmaceutical company developing actinium-225-based radioligand therapies; acquired by BMS for $4.1B, providing a direct valuation and exit benchmark for independent radioligand developers like Affibody.
• Alpha-9 Oncology: Clinical-stage radiopharmaceutical company developing targeted alpha and beta radioligand therapies for solid tumors; profiled alongside Affibody in Clarivate's Companies to Watch report as a peer radioligand innovator.
• PRECIRIX: Belgian clinical-stage biotech developing targeted radiopharmaceuticals using single-domain antibody scaffolds; highly comparable to Affibody in combining small-format targeting scaffolds with radioisotope payloads.
• Perspective Therapeutics: Clinical-stage company developing targeted alpha and beta-emitting radiopharmaceuticals for solid tumors; comparable peer in the radioligand therapy innovation cohort alongside Affibody.

Emerging players

• Telix Pharmaceuticals: Commercial-stage radiopharmaceutical company with approved PSMA-PET imaging agent and pipeline radioligand therapies; relevant comparable as a small-cap public radiopharma peer validating the commercial path Affibody is targeting.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/affibody-ab

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds3 records

Investors3 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Affibody