Complement Therapeutics
Complement Therapeutics is a clinical-stage biotechnology company developing AAV2-based gene therapies for complement-mediated diseases, with lead asset CTx001 in Phase I/II trials for geographic atrophy secondary to AMD. Founded 2021, spun out of the University of Manchester.
- Company typePrivate
- Founded2021
- HeadquartersLondon, United Kingdom
- Headcount11–50
- GTM typeB2B
- OfferingHardware or Manufacturing
What Complement Therapeutics does
Complement Therapeutics is a clinical-stage biotechnology company developing therapeutics for complement-mediated diseases, with its primary focus on geographic atrophy (GA) secondary to age-related macular degeneration (AMD) — a condition affecting over 5 million people globally that currently has no approved treatment. The company was spun out of the University of Manchester in 2021, founded on pioneering research by Prof Simon Clark, Prof Paul Bishop, and Dr Richard Unwin into the role of Factor H-Related (FHR) proteins in AMD pathogenesis, published in Nature Communications (2020) and the American Journal of Human Genetics (2021). Its lead asset CTx001 is an AAV2-based gene therapy that delivers mini-CR1 (a truncated, secreted form of Complement Receptor 1) via subretinal injection, enabling sustained modulation of both the classical and alternative complement pathways from a single administration with broad ocular biodistribution including the choriocapillaris. The company also operates the Complement Precision Medicine (CPM) platform, a proprietary mass spectrometry system for simultaneous quantification of complement proteins from blood samples to support patient stratification and disease monitoring.
The company operates a pre-revenue clinical-stage business model in which future revenue is contingent on commercialization of CTx001 either independently or through partnership or acquisition by a larger pharmaceutical company following clinical validation. Current operations span three jurisdictions: Complement Therapeutics GmbH in Munich (German headquarters), Complement Therapeutics Ltd in London and Stevenage (UK subsidiary with research laboratories at Stevenage Bioscience Catalyst), and Complement Therapeutics Inc in the United States (supporting US clinical operations). Manufacturing of CTx001 clinical supply is conducted through a strategic partnership with Pharmaron at GMP facilities in Liverpool, UK. Clinical trials are conducted at leading retinal centers, with the i-GAIN natural history study enrolling over 230 participants across 12 UK sites and 10 US centers, and the Opti-GAIN Phase I/II trial designed for 75 participants with GA secondary to AMD.
The company has raised approximately €77 million in disclosed venture funding (€5M seed in February 2022 from BioGeneration Ventures and Forbion; €72M Series A in April 2023 led by Gimv and Forbion with participation from BGV, Panakès Partners, Cambridge Innovation Capital, Hadean Ventures, and Seroba Life Sciences). Complement Therapeutics has assembled a leadership team with deep ophthalmology and gene therapy experience drawn from Bayer, Novartis, Alexion, Genzyme, Autolus, and Prothelia. The company has secured multiple regulatory designations — MHRA Innovation Passport (November 2022), FDA IND clearance (October 2025), FDA Fast Track Designation (January 2026), and UK CTA approval (January 2026) — and dosed its first patient in the Opti-GAIN Phase I/II trial in March 2026, completing Cohort 1 dosing with favorable IDMC recommendation to proceed with dose escalation in May 2026.
Complement Therapeutics firmographics
Firmographics- Name
- Complement Therapeutics
- Legal name
- Complement Therapeutics Limited
- Website
- https://complementtx.com
- Company type
- Private
- Founded year
- 2021
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Complement Therapeutics is a clinical-stage biotechnology company developing AAV2-based gene therapies for complement-mediated diseases, with lead asset CTx001 in Phase I/II trials for geographic atrophy secondary to AMD. Founded 2021, spun out of the University of Manchester.
- Ownership category
- akta.pro rank
Complement Therapeutics industry classification
Industry- Product category
- Gene Therapy
- NAICS
- Medical Laboratories (621511), Medical and Diagnostic Laboratories (6215), Medical and Diagnostic Laboratories (62151)
- SIC
- Services-Medical Laboratories (8071), Laboratory Analytical Instruments (3826), In Vitro & In Vivo Diagnostic Substances (2835)
- akta.pro primary industry
- Transplantation & Advanced Therapies Pharmaceuticals (incl. Cell & Gene Therapies) (HLAIAAAO)
- akta.pro secondary industries
- Plasma-Derived Protease Inhibitors & Complement Modulators (e.g., C1 Esterase Inhibitor) (HLAIAHAF), Gene Therapy Analytical Testing & QC (potency, vg/ddPCR, infectivity, RCL/RCA) (HLAAACAK), Companion Diagnostic (CDx) Co-Development Services (biopharma partnerships, clinical strategy) (HLAAAMAB)
Keywords
Where Complement Therapeutics is headquartered
LocationHeadquarters
- HQ city
- London
- HQ country
- United Kingdom
- HQ region
- Europe
Offices4 records
Markets served
Complement Therapeutics business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Technology or R&D, Personnel, Operations, Infrastructure, Marketing or Sales
Revenue model
- Gene Therapy Development and Commercialization: Pre-revenue clinical stage biotech. Revenue expected from commercialization of CTx001 upon regulatory approval. Business model based on developing novel therapeutics through clinical trials and either commercializing directly or through partnership/acquisition by larger pharmaceutical company.
Go-to-market motion1 record
Distribution channels1 record
Marketing channels5 records
Complement Therapeutics product offering
Product offeringCore offering
Complement Therapeutics is a clinical-stage biotechnology company developing an investigational AAV2-based gene therapy (CTx001) that delivers mini-CR1 to provide sustained modulation of complement pathways for the treatment of Geographic Atrophy secondary to age-related macular degeneration. The company also operates a proprietary Complement Precision Medicine (CPM) mass spectrometry platform that simultaneously quantifies multiple complement proteins from a single blood sample to support patient stratification and disease monitoring.
Product overview
Complement Therapeutics is developing a portfolio of treatments for complement-mediated diseases, with two primary offerings: CTx001 as the lead AAV2-based gene therapy product for Geographic Atrophy secondary to AMD, and the Complement Precision Medicine (CPM) Platform as a diagnostic companion tool for patient stratification and disease monitoring. The company is also developing additional therapeutic candidates aimed at systemic modulation of the complement system for non-ocular indications.
Differentiator
Problem solved
Functional benefit
Products and services
- CTx001 An investigational AAV2-based gene therapy candidate designed to deliver mini-CR1 (a truncated and secreted form of Complement Receptor 1) for the treatment of Geographic Atrophy secondary to Age-related Macular Degeneration. CTx001 enables sustained local modulation of multiple complement pathways following a single subretinal injection, with the potential to provide durable, one-time treatment benefits. Currently in Phase I/II Opti-GAIN clinical trial with 75 participants planned.
- Complement Precision Medicine (CPM) Platform A proprietary mass spectrometry-based platform that enables the simultaneous measurement of an array of complement proteins from a single systemically drawn blood sample, including C3 and its breakdown products, Factor I, Factor H, FHL-1, and the FHR family of proteins. The platform facilitates patient stratification and disease monitoring for clinical trials and supports the subsequent commercialization of therapeutic assets.
Quantifiable outcome
- Phase I/II Opti-GAIN trial enrolling 75 participants with 2-year safety/efficacy assessment plus 5-year follow-up
- +2 more outcomes
Companies that use Complement Therapeutics
Customer profileNamed customers2 records
Segments2 records
Ideal customer profiles2 records
Complement Therapeutics technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
Complement Therapeutics partnerships and signals
Strategic signalPartnerships
Five partnerships are on record, tiered core and major.
- Cell and Gene Therapy Catapult (CGT Catapult)coreTwo-year collaborative project to intensify perfusion processes and standardize AAV manufacturing for systemic diseases. Awarded over £1 million Innovate UK grant. Partnership involves Touchlight and Pharmaron Biologics.
- TouchlightmajorCollaboration on innovative rAAV production using Touchlight's enzyme-based doggybone DNA (dbDNA) manufacturing platform. Project aims to improve AAV yield and lower manufacturing costs compared to traditional plasmid DNA production.
- Stevenage Bioscience CatalystmajorWorld-leading biotech cluster housing state-of-the-art laboratory facilities. Complement Therapeutics opened research labs at SBC campus in Stevenage, UK for advancing pipeline asset development.
- PharmaroncoreStrategic partnership for development and clinical manufacture of CTx001 gene therapy. Project commenced December 2022 at Pharmaron's GMP facilities in Liverpool, UK. CMC team provides technical expertise in ocular gene therapy development.
- University of ManchestercoreCompany spun out from University of Manchester based on pioneering research by founders Prof Simon Clark, Prof Paul Bishop, and Dr Richard Unwin into FHR proteins and complement cascade.
Scale indicators5 records
Recent moves9 records
Expansion highlights6 records
Complement Therapeutics competitors and assessment
Company assessmentDirect peers
- Apellis Pharmaceuticals: Commercial-stage biotech whose lead product Syfovre (pegcetacoplan) is an approved C3 inhibitor for geographic atrophy secondary to AMD. Most direct commercial competitor to CTx001 in the same indication, with established physician relationships and reimbursement infrastructure.
- Astellas Pharma (Iveric Bio): Acquired Iveric Bio in 2023 to gain Izervay (avacincaptad pegol), a C5 inhibitor approved for geographic atrophy. Direct complement-pathway competitor in the same indication, with global commercial reach that CTx001 would ultimately need to compete against or partner with.
- REGENXBIO: Gene therapy company with an AAV platform and clinical programs in retinal diseases (ABBV-RGX-314 for wet AMD via subretinal/suprachoroidal delivery). Closely comparable modality (AAV ocular gene therapy), delivery route overlap, and development-stage proximity.
- Gyroscope Therapeutics (Novartis): Acquired by Novartis in 2021 for ~$800M; developed GT005, an AAV-based gene therapy targeting complement factor I for geographic atrophy. Highly comparable therapeutic mechanism (complement modulation via AAV gene therapy in GA) and indication overlap.
- uniQure: Clinical-stage gene therapy company developing AAV-based therapies with programs in CNS and other indications. Comparable as an AAV gene therapy developer facing similar manufacturing, regulatory, and clinical-stage challenges.
- Annexon Biosciences: Clinical-stage complement-focused biotech developing classical-pathway inhibitors (C1q antagonists) for geographic atrophy and other complement-mediated diseases. Closely comparable as a complement-pathway therapeutic competitor targeting similar indications.
Emerging players
- Adverum Biotechnologies: Clinical-stage gene therapy company developing AAV-based therapies for ocular diseases including wet AMD. Comparable as an AAV gene therapy developer in ophthalmology with similar modality, regulatory pathway, and manufacturing challenges.
Broad incumbents
- BioMarin Pharmaceutical: Established rare-disease biotech with multiple approved AAV-based gene therapies (e.g., Roctavian for hemophilia A). Relevant as a gene therapy commercialization benchmark and potential strategic acquirer of platform AAV/complement assets.
- Spark Therapeutics (Roche): Roche-owned gene therapy subsidiary (Luxturna) with AAV ocular and other gene therapy capabilities. Comparable as a commercial-stage AAV gene therapy player; relevant strategic acquirer for ophthalmology-focused gene therapy platforms.
- Regeneron Pharmaceuticals: Develops Eylea (aflibercept), the standard-of-care anti-VEGF for wet AMD with multi-billion-dollar franchise, and has early-stage pipeline interest in dry AMD/GA. Strategic acquirer profile and relevant comparator for ophthalmology commercial dynamics.
Market position
Strengths5 records
Weaknesses2 records
Competitive moat5 records
Key risks6 records
Key highlights7 records
Customer concentration
Complement Therapeutics social profiles
Digital presenceComplement Therapeutics financial estimates
Financial estimateRevenue estimate
Valuation estimate
Complement Therapeutics leadership team
Management profileNumber of profiles
Profiles12 records
Complement Therapeutics subsidiaries and ownership
Company hierarchySubsidiaries2 records
Complement Therapeutics funding detail
Funding detailFunding overview
Funding rounds3 records
Investors7 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Complement Therapeutics M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Complement Therapeutics
What does Complement Therapeutics do?
Complement Therapeutics is a clinical-stage biotechnology company developing an investigational AAV2-based gene therapy (CTx001) that delivers mini-CR1 to provide sustained modulation of complement pathways for the treatment of Geographic Atrophy secondary to age-related macular degeneration. The company also operates a proprietary Complement Precision Medicine (CPM) mass spectrometry platform that simultaneously quantifies multiple complement proteins from a single blood sample to support patient stratification and disease monitoring.
Is Complement Therapeutics a public or private company?
Complement Therapeutics is a private company. It is classified as venture growth investor backed and is currently operating.
When was Complement Therapeutics founded?
Complement Therapeutics was founded in 2021. It employs 11 to 50 people.
Where is Complement Therapeutics based?
Complement Therapeutics is headquartered in London, United Kingdom, in the Europe region.
How does Complement Therapeutics make money?
One revenue line is on record: gene Therapy Development and Commercialization.
Who are Complement Therapeutics's main competitors?
Direct peers on record are Apellis Pharmaceuticals, Astellas Pharma (Iveric Bio), REGENXBIO, Gyroscope Therapeutics (Novartis), uniQure and Annexon Biosciences. Adverum Biotechnologies is listed as an emerging player. Broad incumbents are BioMarin Pharmaceutical, Spark Therapeutics (Roche) and Regeneron Pharmaceuticals.
Does Complement Therapeutics have an API?
No public API is recorded for Complement Therapeutics.
What industry is Complement Therapeutics in?
Complement Therapeutics's product category is Gene Therapy. Its primary akta.pro industry code is HLAIAAAO, Transplantation & Advanced Therapies Pharmaceuticals (incl. Cell & Gene Therapies), with a secondary code of HLAIAHAF, Plasma-Derived Protease Inhibitors & Complement Modulators (e.g., C1 Esterase Inhibitor). Its NAICS code is 621511 and its SIC code is 8071.