Avrobio stock plunges after reporting clinical data for its AVR-RD-01 gene therapy to treat rare genetic Fabry disease

Shares of Avrobio Inc (NASDAQ:AVRO) tumbled Monday after the gene therapy company shared updates on its lead product candidate AVR-RD-01, which is in clinical trials for the treatment of Fabry disease, a rare genetic disorder that results from the buildup of fat in cells.

Designed to be a one-time therapy, AVR-RD-01 works by inserting the GLA gene that encodes functional α‑galactosidase A (AGA), the enzyme that is deficient in Fabry disease, to enable continuous AGA production and distribution to tissues and organs.

Shares of the Cambridge, Massachusetts-based company plunged 41% to $30.50 Monday morning.

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“First two patients in Phase 1 study continue to demonstrate AGA enzyme activity above the diagnostic range for classic Fabry disease 18 months and six months after receiving AVR-RD-01, respectively,” said the company in a statement.

The company said it was “especially pleased” that the first patient was taken off enzyme replacement therapy and remains off. 

The investigator-sponsored Phase 1 study is designed to assess the safety of AVR-RD-01 in up to six patients with Fabry disease who have been treated with standard of care enzyme replacement therapy for at least six months prior to receiving AVR-RD-01.

“We are encouraged by the AGA enzyme activity we are seeing after treatment with AVR-RD-01 in the first two patients with Fabry disease in the Phase 1 study. Both patients have AGA activity that remains above the diagnostic range for males with classic Fabry disease,” said Avrobio CEO Geoff MacKay.

The company said that enrollment continues in Phase 2 clinical trial.

Gaucher disease gets green light in Canada

Separately, the company said Monday that it received a “no objection” from Health Canada to start a Phase 1/2 study to evaluate gene therapy AVR-RD-02 for the treatment of Gaucher disease, a metabolic disorder where a type of fat (lipid) called glucocerebroside cannot be adequately degraded. 

“We are excited to have achieved this regulatory milestone as a step forward in our activities to move AVR-RD-02, the next gene therapy candidate in our pipeline, into the clinic in 2019,” said MacKay. “We believe there is a significant opportunity for gene therapy to offer a potential cure for a range of lysosomal storage diseases, and we are building a pipeline of product candidates to bring this new treatment paradigm to patients.”

Contact Uttara Choudhury at [email protected]

Follow her on Twitter: @UttaraProactive 

Story by ProactiveInvestors