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Exhibit 99.1 AVROBIO Announces 100 % Kidney Substrate Reduction at 12 Months Post - Gene Therapy in First Patient Dosed with plato® Gene Therapy Platform in Fabry Disease Phase 2 Trial Consistent with the 87 % reduction in the first evaluable kidney biopsy , there is complete clearance of Gb3 inclusions in second evaluable kidney biopsy in Fabry disease Phase 2 trial New Gaucher disease type 1 Phase 1/2 data show plasma chitotriosidase levels decreased 49 % and toxic metabolite lyso - Gb1 levels decreased 44 % in first patient at six months post - gene therapy , compared to patient's pre - gene therapy ERT baseline levels Strong new cystinosis Phase 1/2 data across multiple measures for the three dosed patients , including substantial improvement in photophobia in first patient 12 months post - gene therapy Investor and analyst presentation today at 8 a.m. ET CAMBRIDGE , Mass . , Feb. 8 , 2021 - AVROBIO , Inc. ( Nasdaq : AVRO ) , a leading clinical - stage gene therapy company with a mission to free people from a lifetime of genetic disease , today announced a 100 % reduction , or complete clearance , of toxic substrate in the kidney biopsy of the first patient dosed with the platoⓇ gene therapy platform in the ongoing Phase 2 FAB - GTi clinical trial of AVR - RD - 01 , an investigational ex vivo lentiviral gene therapy for Fabry disease . Kidney substrate reduction is the trial's primary efficacy endpoint and has previously been used by the U.S. Food and Drug Administration ( FDA ) in evaluating and approving treatments for Fabry disease . The company also announced six - month data from the first patient dosed in the Phase 1/2 trial of AVR - RD - 02 , an investigational ex vivo lentiviral gene therapy for Gaucher disease type 1 , showing plasma chitotriosidase and the toxic metabolite lyso - Gb1 - key biomarkers of Gaucher disease - had both dropped sharply below the patient's baseline levels achieved on enzyme replacement therapy ( ERT ) before gene therapy was administered . Additionally , all three cystinosis patients in the investigator - sponsored Phase 1/2 trialii of AVR - RD - 04 show strong data across multiple measures and remain off cysteamine pills and eye drops , with trial enrollment completion expected this year . " We are thrilled to begin the new year with this update , which adds to the breadth of strong clinical data we've reported across our leading lysosomal disorder pipeline of single - dose gene therapies , " said Geoff MacKay , president and CEO of AVROBIO . " With 13 patients dosed across three clinical programs , we have observed sustained and potentially transformative