Bloomsbury Genetic Therapies Completes Successful Scientific Advice Meeting with the MHRA regarding its BGT-DTDS Program

– Company intends to move forward with a single, Phase 1/2/3 trial in dopamine transporter deficiency syndrome (DTDS) –


London, UK, 26 April 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, today announced that a successful scientific advice meeting was held with the UK Medicines and Healthcare products Regulatory Agency (MHRA) on 1 March  2023 confirming the formal preclinical requirements to commence a single, Phase 1/2/3 clinical trial with the Company’s product candidate, BGT-DTDS, as a potential new therapeutic for the treatment of DTDS.

The Company discussed its preclinical data package with the MHRA and, based upon the preclinical efficacy data generated in the BGT-DTDS program to date and on precedents from other intra-parenchymal AAV2 gene therapies, in particular in aromatic l-amino acid decarboxylase (AADC) deficiency, a condition similar to DTDS, the MHRA confirmed that it was supportive of the Company initiating a clinical trial for BGT-DTDS in the UK without the need for further non-clinical studies. Delivering such accelerated development is especially key in indications such as DTDS where there is high unmet medical need and no effective treatments.

As a result of the advice and formal feedback received from the MHRA, subject to completing a GMP manufacturing campaign with its chosen vector CDMO partner, the Company intends to move forward with its clinical development plans for BGT-DTDS and aims to submit a combined Clinical Trial and Ethics Committee application for a single, Phase 1/2/3 registrational clinical trial to the MHRA in 2024. The Company is also planning to engage with the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) ahead of trial expansion in those geographies, where it has already obtained orphan drug designations.

“We were grateful to have had this constructive dialogue with the MHRA. It confirmed that our preclinical program includes all the studies and data needed to progress the BGT-DTDS program into the clinic,” said Adrien Lemoine, Co-Founder & Chief Executive Officer of Bloomsbury. “We see this outcome as a validation of our development strategy, both for BGT-DTDS and across our portfolio – namely, relying on platforms based on de-risked capsids/routes of administration to deliver accelerated clinical translation and capital-efficient development. We expect to see further benefits resulting from our approach as we progress our programs to registration.”


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JW Communications

Julia Wilson

Tel: +44 (0)7818 430877


About Bloomsbury Genetic Therapies (“Bloomsbury”)

Bloomsbury is 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. The Company was spun out of UCL and launched in October 2022 with £5M in Seed funding from UCL Technology Fund and is underpinned by world-leading gene therapy and rare disease expertise from the Company’s academic founders, Professor Paul Gissen, Professor Manju Kurian, Professor Ahad Rahim and Professor Simon Waddington. Bloomsbury is building a pipeline of highly differentiated first- or best-in-class programs. For more information, please visit



BGT-DTDS is a neuron-targeted AAV2 investigational gene therapy designed to provide a potentially curative solution to DTDS patients following a one-time intra-brain injection to the substantia nigra and ventral tegmental area. BGT-DTDS has completed preclinical efficacy studies in DTDS and the Company is currently preparing for a first-in-human clinical trial. BGT-DTDS has been granted orphan drug designation for the treatment of DTDS by the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA). For more information, please visit


About Dopamine Transporter Deficiency Syndrome (DTDS)

DTDS is a rare, autosomal recessive childhood neurological disorder with significant disease burden, characterised by a severe parkinsonian movement disorder. DTDS results from biallelic mutations in the SLC6A3 which encodes the dopamine transporter (DAT), a key protein regulating dopaminergic signalling. Dopamine re-uptake by DAT is the principal mechanism by which dopamine is removed and recycled from synapses. Mutations in SLC6A3 result in DAT dysfunction and major dysregulation of dopamine neurotransmission, leading to hyperkinetic movement disorders in the early stages of the disease, and then evolution of parkinsonism-like features (slowing of voluntary movements, loss of facial expression, tremor, stiffness) and eye movement disorders such as oculogyric crises. The disease is often fatal in childhood to teenage years due to unexplained death in sleep or respiratory failure.  There are currently no disease-modifying treatments or approved therapies for DTDS, and patients derive little clinical benefit from available symptom control medications.  The disease is currently poorly diagnosed, due to symptoms similarity with other movement disorders including cerebral palsy, and the number of patients with the condition is unknown.