Bloomsbury Genetic Therapies Announces Clinical Trial Application Accepted by U.K. Regulatory Agency to Initiate Phase 1/2 Gene Therapy Trial of BGT-OTCD for the Treatment of Ornithine Transcarbamylase Deficiency (OTCD)

- First in-human phase 1/2 trial to evaluate the safety, efficacy and tolerability of BGT-OTCD in paediatric patients with confirmed diagnosis of OTCD -

- University College London expects to initiate the clinical trial in Q3 2023 -

London, UK, 15 May 2023 – Bloomsbury Genetic Therapies Limited, a clinical-stage biotechnology company developing potentially curative treatments for patients suffering from rare neurological and metabolic diseases based on clinically proven gene therapy technologies, announced today that that the U.K. Medicines and Healthcare Products Regulatory Agency (MHRA) and the Gene Therapy Advisory Committee (GTAC) have approved the clinical trial application (CTA) submitted by Bloomsbury’s collaborators at University College London (UCL) for the initiation of a phase 1/2 clinical trial of BGT-OTCD, the Company’s liver-targeted AAV-LK03 gene therapy, in paediatric patients diagnosed with OTCD.

The phase 1/2 trial of BGT-OTCD, Halting Ornithine transcarbamylase deficiency with Recombinant AAV in ChildrEn (HORACE) is an open-label, safety, efficacy and dose finding trial and will enrol up to 12 patients aged between 0 and 16 years old diagnosed with OTCD and is expected to begin in the UK in Q3 2023. UCL is the sponsor of the trial with financial support to be provided by Bloomsbury.

“This is a significant milestone for Bloomsbury as BGT-OTCD becomes the company’s first investigational gene therapy to be taken into a clinical trial,” said Adrien Lemoine, Co-Founder & Chief Executive Officer of Bloomsbury. “We are thrilled to collaborate with the teams at UCL and Great Ormond Street Hospital (GOSH) in London on this trial supporting the ongoing development of the BGT-OTCD program and our goal of bringing a one-time, potentially curative treatment to both children and adult patients suffering from this devasting disease.”

“Ornithine transcarbamylase deficiency is a rare genetic disorder that that is characterised by complete or partial lack of the OTC enzyme which causes too much ammonia to accumulate in the body. People with this disease suffer from symptoms including vomiting, impaired voluntary movement and progressive lethargy, which can all progress to brain damage, coma or death if left untreated," said Dr Anupam Chakrapani, Consultant in Metabolic Medicine, GOSH and the trial’s Principal Investigator. “The capsid used in this investigational AAV gene therapy, AAV-LK03, was selected for its enhanced ability to transduce human hepatocytes, and in particular periportal hepatocytes where the urea cycle preferentially takes place. We hope the trial will show that BGT-OTCD could provide sustained curative effect following a single administration even in children with a growing liver.”