AVROBIO has reported positive interim findings from a Phase I/II clinical trial of investigational gene therapy, AVR-RD-04, for cystinosis.

AVR-RD-04 is claimed to genetically modify the hematopoietic stem cells (HSC) of the patient to express a functional version of cystinosin.

Cystinosin is a protein that is deficient in cystinosis patients. 

The collaborator-sponsored trial underway is assessing the safety and efficacy of AVR-RD-04 in adults with the infantile form of cystinosis.

These subjects have received prior treatment with cysteamine, the existing standard of care (SOC). 

According to the initial findings, two subjects had stabilisation of the Beery – Buktenica Developmental Test of the visual-motor integration (VMI) scores and enhanced motor coordination and visual perception following treatment with the gene therapy.

This standardised test is used to assess the brain’s ability to understand and translate visual data into an exact motor response.

Furthermore, post-treatment, subjects were found to be able to produce and distribute functional cystinosin protein across the body, averting the pathological build-up of cystine crystals​.

Continued engraftment was reported with stable vector copy number (VCN) in patients after 12 months.

A favourable safety profile was observed in the trial without any adverse events linked to the drug product reported so far.

Avrobio chief medical officer Essra Ridha said: “We believe the interim data from this ongoing clinical trial demonstrate the potential of gene therapy using patient’s own hematopoietic stem cells to impact the body head-to-toe by restoring functional cystinosin and reducing the accumulation of cystine crystals systemically. 

“With proof-of-concept demonstrated, we continue to lay the groundwork for an Avrobio-sponsored clinical trial planned to begin in 2023 and look forward to our interactions with regulators on our clinical and Chem­istry Man­u­fac­tur­ing and Con­trols (CMC) strategy later this year.”

In February last year, the company reported a complete clearance of toxic substrate in the kidney biopsy of a subject dosed with its plato gene therapy platform in the Phase II FAB-GT trial of AVR-RD-01 for Fabry disease.

Cell & Gene Therapy coverage on Clinical Trials Arena is supported by Cytiva.

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