Venture capitalist Jon Moulton has invested in Infex Therapeutics, a UK biotech company developing new treatments for infections that no longer respond to antibiotics — a problem the World Health Organization describes as one of the top global public health and development threats.
The Alderley Edge-based firm has raised £4.3m in a funding round led by Moulton alongside the GM&C Life Sciences Fund, managed by Catapult Ventures, and existing high-net-worth investors. Proceeds from the round will be used to advance the company’s pipeline of novel anti-infectives targeting antimicrobial resistance (AMR) and other critical-priority infectious diseases.
Infex Therapeutics focuses on acquiring and in-licensing early-stage drug candidates to take them towards clinical proof of concept for life-threatening drug-resistant infections. The company is led by chief executive Dr Peter Jackson and chaired by Moulton, who founded the private equity firm Better Capital.
How Infex is tackling antimicrobial resistance
The company’s lead programme, RESP-X, is an anti-virulence monoclonal antibody designed to treat patients with non-cystic fibrosis bronchiectasis (NCFB) who are chronically colonised by the bacterium Pseudomonas aeruginosa. Unlike traditional antibiotics that kill bacteria directly, RESP-X targets a virulence mechanism that helps P. aeruginosa evade the immune system and cause tissue damage. By deactivating that mechanism, the therapy allows the body’s own immune defences to fight the infection.
Infex has completed Phase 1 studies that demonstrated a sound safety and tolerability profile for RESP-X. A Phase 2a clinical trial in NCFB patients has also been completed, and the company expects to present data from the trial at the American Thoracic Society International Conference. The programme was originally in-licensed from the Japanese pharmaceutical company Shionogi, and Infex sees potential to expand its use into cystic fibrosis, chronic obstructive pulmonary disease and acute hospital infections.
Beyond RESP-X, Infex is developing a second programme called MET-X — a broad-spectrum metallo-beta-lactamase (MBL) inhibitor. Gram-negative bacteria known as Enterobacterales produce MBL enzymes that inactivate beta-lactam antibiotics, driving severe drug-resistant infections. Infex has partnered with Venus Remedies Ltd in India to explore whether MET-X can restore the activity of those antibiotics. The company is also progressing preclinical studies on a class of compounds called BamA inhibitors.
Non-cystic fibrosis bronchiectasis is a chronic lung condition in which the airways widen and become damaged, leading to recurrent infections, breathing difficulties and reduced quality of life. The British Lung Foundation estimates there are more than 300,000 people with the condition in the UK, and at least eight million people globally. Around 30% of NCFB patients have chronic Pseudomonas aeruginosa colonisation. Current treatments include antibiotics to control infections, airway clearance techniques, bronchodilators and corticosteroids. Nebulised antibiotics such as colomycin are used for chronic P. aeruginosa colonisation, and long-term oral macrolides are an alternative, but there are currently no approved preventative treatments for colonisation in NCFB patients. In August 2025, the US Food and Drug Administration approved Insmed’s Brinsupri (brensocatib) as the first medicine specifically for NCFB, though it targets chronic inflammation via a different mechanism.
Antimicrobial resistance already takes a devastating toll. According to the World Health Organization, bacterial AMR was directly responsible for 1.27 million deaths globally in 2019 and contributed to 4.95 million deaths. The WHO’s Global Antimicrobial Resistance and Use Surveillance System (GLASS) 2025 report found that approximately one in six common bacterial infections worldwide are now resistant to first-line antibiotic therapy, and resistance has increased by more than 40% across over 40 pathogen-drug combinations since 2018. If no action is taken, the WHO projects AMR deaths could rise to 10 million by 2050. The World Bank estimates AMR could result in US$1 trillion in additional healthcare costs by 2050 and annual GDP losses of US$1 trillion to US$3.4 trillion by 2030.
The UK government has a 20-year vision for containing and controlling AMR, supported by five-year national action plans. The current plan, ‘Confronting Antimicrobial Resistance 2024 to 2029‘, includes targets such as reducing total antibiotic use in humans by 5% from the 2019 baseline by 2029. However, progress on reducing antibiotic use and drug-resistant infections in humans has been slower than targeted, with increases observed in recent years.
The GM&C Life Sciences Fund, which joined the latest investment round, is a seed and early-stage venture capital fund focused on life sciences businesses in the Greater Manchester and Cheshire & Warrington region. It was launched in 2015 with an initial size of around £31m and has since leveraged over £100m in private sector co-investment. The fund is managed by Catapult Ventures, an investor in early-stage deep tech startups.
Investor backing
Dr Peter Jackson, chief executive of Infex Therapeutics, said: “We are delighted to secure this investment led by Jon Moulton, with support from the Greater Manchester and Cheshire Lifescience Investment Fund and our existing investors. This funding represents strong validation of our progress in developing novel anti-infectives to address the critical global threat of antimicrobial resistance.”
Jon Moulton, who chairs Infex, said: “We have supported Infex from the beginning and continue to be impressed by the company’s scientific progress and strategic execution.” He highlighted the RESP-X programme and added: “This additional investment reflects our strong conviction in both the team and its innovative approach to tackling antimicrobial resistance.”
Nick Wright, chief executive of Catapult Ventures, said: “Infex Therapeutics has made excellent scientific progress since we first invested several years ago. The company has clearly established itself as a world leader in the AMR and related space and the data it is generating is very compelling.”
