Complement Therapeutics Announces Completion of Cohort 2 Dosing and Favourable IDMC Recommendation to Proceed to High Dose and Expansion Cohorts in the Phase I/II Opti-GAIN Study

Cohort 1 enrolment completed in the Company’s first-in-human Opti-GAIN clinical trial of CTx001 in Geographic Atrophy (GA) secondary to AMD The Independent Data Monitoring Committee (IDMC) has recommended proceeding with dose escalation after planned safety assessment of first dose cohort CTx001 is an investigational AAV gene therapy that potently downregulates multiple complement pathways and has the potential to be a highly differentiated approach to the treatment of GA secondary to AMD. Opti-GAIN is among the first GA studies to prospectively evaluate ellipsoid zone (EZ) integrity as well as the focal microperimetry as primary structural and functional endpoints Munich, Germany – 27 May 2026 - Complement Therapeutics GmbH (CTx), a clinical-stage biotechnology company developing next-generation therapeutics for complement-mediated diseases, today announced the completion of dosing for Cohort 1 in the Opti-GAIN clinical trial of CTx001 in patients with Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD). The Company also announced that the IDMC has completed its review of safety data from Cohort 1, identified no significant safety concerns, and recommended that enrolment in Cohort 2 proceed. “Completing enrolment in Cohort 1 and receiving a favourable IDMC recommendation are together an important step forward for Opti-GAIN and for CTx001,” said Dr Rafiq Hasan, Chief Executive Officer of Complement Therapeutics. “The IDMC’s review provides the first external validation of CTx001’s safety profile in human subjects, and we are very pleased to have received a recommendation to proceed. With Cohort 2 now open, we continue to advance the dose-escalation phase whilst looking forward to reporting important updates in the second half of 2026. Importantly, the novel endpoints we are deploying, particularly EZ integrity and focal microperimetry assessed against each patient’s own pre-treatment baseline, are designed to give us the most sensitive possible read on whether CTx001 can demonstrate potential efficacy.” Opti-GAIN employs a differentiated endpoint strategy designed to sensitively evaluate structural and functional changes following subretinal gene therapy at the level of the individual patient. The study is among the first in Geographic Atrophy to prospectively evaluate two novel endpoints: Ellipsoid Zone (EZ) Integrity: A structural assessment reflecting the health of photoreceptors with the potential to provide an early and sensitive measure of structural disease progression and potential treatment effects of CTx001. Focal Optical Coherence Tomography (OCT) – based Microperimetry: A functional assessment that precisely maps retinal sensitivity in areas of geographic atrophy, providing a more sensitive and clinically meaningful assessment of functional change before and after administration of CTx001 within the treated eye. “The novel design characteristics of the Opti-GAIN study have the ability to provide an early indication of the safety, tolerability and potential efficacy of CTx001 in GA secondary to AMD. This process is now well underway with encouraging early data from the first cohort and patients already in the run-in for upcoming dosing.” said M. Ali Memon, Chief Medical Officer of Complement Therapeutics. The Opti-GAIN and Pre-GAIN studies are being conducted by the company’s UK subsidiary. More information is available at ClinicalTrials.gov, including Opti-GAIN (NCT07392255) and Pre-GAIN (NCT07144137). About the CTx001 program CTx001 is an investigational AAV2-based gene therapy in development for Geographic Atrophy secondary to Age-related Macular Degeneration. The therapy is designed to deliver mini-CR1, a truncated and secreted form of Complement Receptor 1, to enable sustained local modulation of multiple complement pathways following a single subretinal injection. About the Opti-GAIN Trial Opti-GAIN is a Phase I/II multi-centre clinical study evaluating the safety, tolerability and efficacy of CTx001 administered via a single subretinal injection in 75 participants with Geographic Atrophy secondary to Age-related Macular Degeneration. Safety and efficacy will be assessed regularly over 2 years, followed by annual long-term safety follow-up for up to 5 years. About the Pre-GAIN Trial Pre-GAIN is a multi-centre, non-interventional, natural history study designed to provide insights into the short-term progression of Geographic Atrophy secondary to Age-related Macular Degeneration. The study is intended to characterise structural and functional measures of GA progression and may help identify participants for Opti-GAIN. About Geographic Atrophy Geographic Atrophy (GA) is a leading cause of blindness in the elderly and represents the advanced stage of dry age-related macular degeneration. It is characterised by the progressive degeneration of photoreceptors, retinal pigment epithelium, and choriocapillaris, resulting in irreversible vision loss. GA affects over 5 million people globally and remains a significant unmet clinical need. About Complement Therapeutics GmbH: Complement Therapeutics GmbH (CTx) is a German-headquartered clinical-stage biotechnology company focused on the research and development of novel therapeutics for complement-mediated diseases. The Company is a spinout from the University of Manchester and is based on the pioneering research of its founders into novel targets within the complement cascade. Our lead investigational product (CTx001) is being evaluated as a potential gene therapy for GA, a leading cause of blindness. Additional programs will evaluate potential therapeutic opportunities in other complement-mediated conditions. The Company has subsidiaries in the UK (Complement Therapeutics Ltd) and in the USA (Complement Therapeutics Inc) as well as research laboratories in Stevenage, UK. –Ends– For more information please visit: https://complementtx.com/ Company Contact Dr Rafiq Hasan, CEO and Managing Director Complement Therapeutics GmbH Email: info@complementtx.com

First patient dosed in Opti-GAIN, a first-in-human Phase I/II clinical trial of CTx001 in Geographic Atrophy secondary to AMD CTx001 is an investigational AAV-based gene therapy designed to deliver mini-CR1, a potent modulator of multiple pathways of the complement system Opti-GAIN is supported by Pre-GAIN, an ongoing natural history study designed to provide short-term GA progression insights and support the development of novel endpoints Munich, Germany – 25 Mar 2026 – Complement Therapeutics GmbH (CTx), a clinical-stage biotechnology company developing next-generation therapeutics for complement-mediated diseases, today announced that the first patient has been dosed in Opti-GAIN, the Company’s first-in-human Phase I/II clinical trial of CTx001 in patients with Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD). Opti-GAIN is a multi-centre Phase I/II study evaluating the safety, tolerability and preliminary efficacy of CTx001 administered via a single subretinal injection. Part 1 is an open-label, dose-escalation study across three dose cohorts, followed by a dose-expansion phase in Part 2. The Opti-GAIN study is being conducted by the UK subsidiary of the company. “Geographic Atrophy remains an area of significant unmet need, and there is a clear need to evaluate novel approaches for patients facing progressive vision loss,” said Dr Arshad M. Khanani, the trial’s Chief Investigator and Director of Clinical Research at Sierra Eye Associates, Reno, Nevada, USA. “I am pleased to be involved in this first-in-human study and to have administered CTx001 to the first patient in Opti-GAIN. I look forward to working with Complement Therapeutics to deepen our understanding of this promising one-time investigational gene therapy approach in patients with GA secondary to AMD.” CTx001 is an investigational AAV2-based gene therapy designed to transduce retinal cells with a construct encoding mini-CR1, a truncated and secreted form of Complement Receptor 1 that can modulate both the alternative and classical complement pathways. Subretinal delivery of CTx001 enables local retinal production of mini-CR1, whilst the small size of mini-CR1 may support penetration across Bruch’s membrane resulting in broad ocular biodistribution, including the choriocapillaris. Consequently, CTx001 builds on clinically validated complement biology in GA whilst aiming for a potentially best in class profile due to broad ocular biodistribution, strong potency and modulation of multiple complement pathways combined with extended durability. The Opti-GAIN study is being advanced alongside Pre-GAIN, the Company’s ongoing natural history study in GA currently enrolling in both the United States and the United Kingdom. Together, these studies are intended to support patient selection and the evaluation of novel structural and functional endpoints, including ellipsoid zone (EZ) and focal Optical Coherence Tomography (OCT)-based microperimetry. Opti-GAIN is among the first studies to prospectively evaluate focal OCT-based microperimetry, an approach that has the potential to advance how the treatment effect is assessed in Geographic Atrophy. “Dosing the first patient in Opti-GAIN is an important milestone for Complement Therapeutics and for the advancement of CTx001 in Geographic Atrophy,” said Dr Rafiq Hasan, Chief Executive Officer of Complement Therapeutics. “We believe the combination of a differentiated asset and an integrated clinical development strategy sets CTx001 apart. By advancing Opti-GAIN alongside Pre-GAIN, we are generating natural history and interventional data to better inform patient selection, endpoint strategy and future clinical development.” Dr Muhammad Ali Memon, Chief Medical Officer of Complement Therapeutics, added: “The precise surgical dosing strategy, adaptive immunomodulatory regimen and well-characterised patient population, from Complement’s non-interventional i-GAIN and Pre-GAIN studies, provides a strong platform for CTx001 to demonstrate a therapeutic effect within Opti-GAIN”. More information about the Company’s clinical studies is available at ClinicalTrials.gov, including Opti-GAIN ( NCT07392255 ) and Pre-GAIN ( NCT07144137 ). About the CTx001 program CTx001 is an investigational AAV2-based gene therapy in development for Geographic Atrophy secondary to Age-related Macular Degeneration. The therapy is designed to deliver mini-CR1, a truncated and secreted form of Complement Receptor 1, to enable sustained local modulation of multiple complement pathways following a single subretinal injection. About the Opti-GAIN Trial Opti-GAIN is a Phase I/II multi-centre clinical study evaluating the safety, tolerability and efficacy of CTx001 administered via a single subretinal injection in 75 participants with Geographic Atrophy secondary to Age-related Macular Degeneration. Safety and efficacy will be assessed regularly over 2 years, followed by annual long-term safety follow-up for up to 5 years. About the Pre-GAIN Trial Pre-GAIN is a multi-centre, non-interventional, natural history study designed to provide insights into the short-term progression of Geographic Atrophy secondary to Age-related Macular Degeneration. The study is intended to characterise structural and functional measures of GA progression and may help identify participants for Opti-GAIN. About Geographic Atrophy Geographic Atrophy (GA) is a leading cause of blindness in the elderly and represents the advanced stage of dry age-related macular degeneration. It is characterised by the progressive degeneration of photoreceptors, retinal pigment epithelium, and choriocapillaris, resulting in irreversible vision loss. GA affects over 5 million people globally and remains a significant unmet clinical need. About Complement Therapeutics GmbH: Complement Therapeutics GmbH (CTx) is a German-headquartered clinical-stage biotechnology company focused on the research and development of novel therapeutics for complement-mediated diseases. The Company is a spinout from the University of Manchester and is based on the pioneering research of its founders into novel targets within the complement cascade. Our lead investigational product (CTx001) is being evaluated as a potential gene therapy for GA, a leading cause of blindness. Additional programs will evaluate potential therapeutic opportunities in other complement-mediated conditions. The Company has subsidiaries in the UK (Complement Therapeutics Ltd) and in the USA (Complement Therapeutics Inc) as well as research laboratories in Stevenage, UK. –Ends– For more information please visit: https://complementtx.com/ Company Contact Dr Rafiq Hasan, CEO and Managing Director Complement Therapeutics GmbH Email: info@complementtx.com

CTx001 is an investigational AAV-based gene therapy designed to modulate multiple pathways within the complement system UK Clinical Trial Authorisation (CTA) approval enables initiation of the Phase I/II Opti-GAIN clinical trial in the United Kingdom The approval follows recent FDA IND clearance and Fast Track Designation for CTx001, supporting a multinational first-in-human clinical development programme Munich, Germany – 29th Jan 2026 – Complement Therapeutics GmbH (CTx), a clinical-stage biotechnology company developing next-generation therapeutics for complement-mediated diseases, today announced that it has received Clinical Trial Authorisation (CTA) approval in the United Kingdom for CTx001, the company’s investigational gene therapy programme for Geographic Atrophy (GA) secondary to age-related macular degeneration (AMD). The CTA application for CTx001 has been approved by the Medicines and Healthcare products Regulatory Agency (MHRA). This approval builds on Complement Therapeutics’ recent U.S. Food and Drug Administration (FDA) Investigational New Drug (IND) clearance, for which the programme also holds Fast Track Designation in the United States. Together, these regulatory milestones enable acceleration of the company’s clinical development programme across sites in both the US and UK. “UK CTA approval enables us to initiate an innovative first-in-human clinical development programme for CTx001 in Geographic Atrophy,” said Dr. Rafiq Hasan, Chief Executive Officer of Complement Therapeutics. “The Opti-GAIN study has been carefully designed to leverage patients’ natural history data and incorporates novel imaging and functional endpoints to better characterise disease progression and treatment response. Together with our recent FDA IND clearance and Fast Track Designation, this positions us to evaluate CTx001 through a rigorous, multinational clinical programme across the US and UK.” CTx001 is an investigational adeno-associated virus (AAV)-based gene therapy designed to deliver a truncated version of Complement Receptor 1 (mini-CR1), enabling long-term modulation of the classical and alternative pathways of the complement cascade. Given its small size, mini-CR1 has the potential to penetrate different compartments of the eye and thereby address the inflammation associated with GA in a more robust manner. Dysregulation of the complement system is recognised as a key driver of disease progression in GA, an advanced form of dry AMD that leads to progressive and irreversible vision loss and for which treatment options remain limited. The Opti-GAIN (Optimised Geographic Atrophy INterventional) trial is an international, first-in-human, open-label interventional Phase I/II study that leverages data from an extensive natural history programme. The clinical design of Opti-GAIN enables a detailed assessment of disease progression and treatment response using innovative endpoints, including evaluation of ellipsoid zone (EZ) attenuation and focal microperimetry. The study is therefore well placed to evaluate the safety, tolerability and preliminary efficacy of CTx001 in patients with GA secondary to AMD. The trial will enrol patients across leading retinal centres with first patient dosing expected in Q1 2026. About Complement Therapeutics GmbH: Complement Therapeutics GmbH (CTx) is a German headquartered clinical-stage biotechnology company focused on the research and development of novel therapeutics for complement-mediated diseases. The Company is a spinout from the University of Manchester and is based on the pioneering research of its founders into novel targets within the complement cascade. Our lead investigational product (CTx001) is being evaluated as a potential gene therapy for GA, a leading cause of blindness. Additional programs will evaluate potential therapeutic opportunities in other complement-mediated conditions. The Company has subsidiaries in the UK (Complement Therapeutics Ltd) and in the USA (Complement Therapeutics Inc) as well as research laboratories in Stevenage, UK. About Geographic Atrophy: Geographic Atrophy (GA) is a leading cause of blindness in the elderly and represents the advanced stage of dry age-related macular degeneration. It is characterised by the progressive degeneration of photoreceptors, retinal pigment epithelium, and choriocapillaris, resulting in irreversible vision loss. GA affects over 5 million people globally and remains a significant unmet clinical need. –Ends– For more information please visit: https://complementtx.com/ Company Contact Dr Rafiq Hasan, CEO and Managing Director Complement Therapeutics GmbH Email: info@complementtx.com

Munich, Germany – 8th Jan 2026 – Complement Therapeutics GmbH (CTx), a clinical-stage biotechnology company developing next-generation therapeutics for complement-mediated diseases, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation for CTx001, the company’s lead gene therapy candidate for the treatment of Geographic Atrophy (GA) secondary to Age-related Macular […]

Complement Therapeutics GmbH (CTx), a clinical-stage biotechnology company developing next-generation therapeutics for complement-mediated diseases, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation for CTx001, the company’s lead gene therapy candidate for the treatment of Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD).

Munich, Germany – 26th November 2024 – Complement Therapeutics GmbH (CTx), a preclinical stage biotechnology company developing novel therapeutics for complement-mediated diseases, today announced the appointment of Dr Muhammad Ali Memon as its Chief Medical Officer, effective 1st January 2025.

Complement Therapeutics GmbH (CTx), a biotechnology company developing next-generation therapeutics for complement-mediated diseases, today announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for CTx001, the company’s lead gene therapy candidate. The IND clearance enables initiation of the Opti-GAIN Phase I/II clinical trial in patients with Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD).

Munich, Germany – 9th May 2024 – The Cell and Gene Therapy Catapult (CGT Catapult), an independent innovation and technology organisation specialising in the advancement of the cell and gene therapy industry; Touchlight, a company pioneering enzymatic DNA production; and Complement Therapeutics, a preclinical stage biotechnology company developing novel therapeutics for complement-mediated diseases, today announce that they have been awarded over £1 million in a grant from Innovate UK, as part of the ‘Innovative Technologies: Nucleic Acid Medicines Manufacture’ competition.

Munich, Germany – 14th December 2023 – Complement Therapeutics GmbH (CTx), a preclinical stage biotechnology company developing novel therapeutics for complement-mediated diseases, today announced the formation of its Medical Advisory Board which will help guide the development of the company’s innovative therapeutic pipeline including its lead investigational product CTx001, a gene therapy for geographic atrophy. […]