Disclaimer This presentation has been prepared by AVROBIO, Inc. ("AVROBIO") for informational purposes only and not for any other purpose. Certain information contained in this presentation and statements made orally dur

ASGCT 2020 Fabry & Cystinosis Data

Update May 13, 2020 Exhibit 99.1

Disclaimer This presentation has been

prepared by AVROBIO, Inc. ("AVROBIO") for informational purposes only and not for any other purpose. Certain information contained in this presentation and statements made orally during this presentation relate to or are based on

studies, publications, surveys and other data obtained from third-party sources and AVROBIO's own internal estimates and research. While AVROBIO believes these third-party sources to be reliable as of the date of this presentation, it has not

independently verified, and AVROBIO makes no representation as to the adequacy, fairness, accuracy or completeness of any information obtained from third-party sources. While AVROBIO believes its internal research is reliable, such research has not

been verified by any independent source. This presentation may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words and

phrases such as "aims," "anticipates," "believes," "could," "designed to," "estimates," "expects," "forecasts," "goal,"

"intends," "may," "plans," "possible," "potential," "seeks," "will," and variations of these words and phrases or similar expressions that are intended to identify

forward-looking statements. These forward-looking statements include, without limitation, statements regarding our business strategy, prospective products and goals, the therapeutic potential of our investigational gene therapies, the design,

commencement, enrollment and timing of ongoing or planned clinical trials, clinical trial results, product approvals and regulatory pathways, potential regulatory approvals and the timing thereof, anticipated benefits of our gene therapy platform

including potential impact on our commercialization activities, the expected benefits and results of our implementation of the plato platform in our clinical trials and gene therapy programs, the expected benefits of Saladax

Biomedical's immunoassay kits and Magenta Therapeutics' antibody-drug conjugate (MGTA-117), including, in each case, the potential application to our investigational gene therapies, the expected safety profile of our investigational gene

therapies, timing and likelihood of success, plans and objectives of management for future operations, and future results of anticipated products. Any such statements in this presentation that are not statements of historical fact may be deemed to

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uncertainties include, but are not limited to, the risk that any one or more of AVROBIO's investigational gene therapies will not be successfully developed or commercialized, the risk of cessation or delay of any ongoing or planned clinical

trials of AVROBIO or our collaborators or of encountering challenges in the enrollment or dosing in such clinical trials, the risk that AVROBIO may not realize the intended benefits of our gene therapy platform, including the features of our plato

platform, the risk that AVROBIO may not realize the intended benefit of Saladax's immunoassay kits and/or Magenta's MGTA-117 with respect to AVROBIO's investigational gene therapies, the risk that our investigational gene therapies

or procedures in connection with the administration thereof will not have the safety or efficacy profile that we anticipate, the risk that prior results, such as signals of safety, activity or durability of effect, observed from preclinical or

clinical trials, will not be replicated or will not continue in ongoing or future studies or trials involving AVROBIO's investigational gene therapies, the risk that we will be unable to obtain and maintain regulatory approvals for our

investigational gene therapies, the risk that the size and growth potential of the market for our investigational gene therapies will not materialize as expected, risks associated with our dependence on third-party suppliers and manufacturers, risks

regarding the accuracy of our estimates of expenses and future revenue, risks relating to our capital requirements and needs for additional financing, risks relating to clinical trial and business interruptions resulting from the COVID-19 outbreak

or similar public health crises, including that such interruptions may materially delay our development timeline and/or increase our development costs or that data collection efforts may be impaired or otherwise impacted by such crises, and risks

relating to our ability to obtain and maintain intellectual property protection for our investigational gene therapies. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause

AVROBIO's actual results to differ from those contained in the forward-looking statements, see the section entitled "Risk Factors" in AVROBIO's most recent Quarterly Report on Form 10-Q, as well as discussions of potential

risks, uncertainties and other important factors in AVROBIO's subsequent filings with the Securities and Exchange Commission. AVROBIO explicitly disclaims any obligation to update any forward-looking statements except to the extent required by

law. Note regarding trademarks: plato is a trademark of AVROBIO. Other trademarks referenced in this presentation are the property of their respective owners.

Positive trends at six months,

including kidney function measures eGFR and serum creatinine measures trending positively at 6 months Pill burden remains significantly lower than at baseline ASGCT 2020 data update - key takeaways plato continues to perform One-month plasma

lyso-Gb3 decrease of 43% vs. baseline Three-month leukocyte and plasma enzyme activity levels 3x greater than mean of other three patients at same timepoint in Phase 2 trial Rapid neutrophil and platelet recovery with minimal lymphocyte depletion

post Bu90 conditioning First Fabry plato patient Sustained long-term positive trends Patient 1 in the Phase 2 trial continues to show stable leukocyte and plasma AGA enzyme activity, now out 22 months Patient 3 in the Phase 2 trial shows

increased leukocyte and plasma AGA enzyme activity, decreased plasma lyso-Gb3 level, and stable VCN at new time points All three Phase 1 patients off ERT remain off ERT Long-term Fabry patient data Cystinosis Patient 1 data New data show consistent

results across Fabry disease and cystinosis programs

Multiple programs in the clinic

Investigational Gene Therapy Proof-of-Concept IND-Enabling Phase 1/2 Commercial Rights Fabry AVR-RD-01 AVROBIO Gaucher AVR-RD-02 AVROBIO Cystinosis AVR-RD-04 AVROBIO Pompe AVR-RD-03 Preclinical AVROBIO Phase 2 Phase 1/2 Phase 1/2 10 patients dosed

to date IND: Investigational New Drug

Fabry Disease AVR-RD-01

Goals for gene therapy in Fabry disease

UNMET NEEDS: Kidney function Unmet needs: proteinuria, polyuria, kidney failure Cardiac function Unmet needs: left ventricular hypertrophy, fibrosis, heart failure Neuropathic pain Unmet needs: pain and burning sensations in hands and feet, pain

crises Everyday burden of illness and life expectancy Unmet needs: fatigue, inability to sweat, joint pain, abdominal pain, diarrhea, vomiting, cloudy vision, hearing loss, tinnitus, rash, angiokeratomas, biweekly infusions, shortened lifespan CNS

complications Unmet needs: TIA/stroke, depression, impaired executive function, white matter hyperintensities Sources: Wanner C et al, Med Genetics and Metab, 2018; Burlina A, JIEMS, 2016 CNS: Central Nervous System; TIA: Transient Ischemic

Two AVR-RD-01 Fabry clinical trials 9

patients dosed across Phases 1 and 2 PHASE 1 Investigator-Sponsored Trial* PHASE 2 AVRO - FAB-201 Trial Patients Patients Key Objective Key Objectives n = 5 (fully enrolled) On ERT > 6 months prior to enrollment 18-50 year-old males n =

8-12 (4 patients dosed to-date) Treatment-naive 16-50 year-old males Safety and preliminary efficacy Safety and efficacy * Sponsored by FACTs team (Fabry Disease Clinical Research and Therapeutics) in Canada

Infuse AVR-RD-01 Day 0 Plasma AGA

Missing Plasma AGA Analysis Leukocyte AGA Infuse AVR-RD-01 Day 0 *Lab A: Mayo Clinic Laboratories; Lab B: Rupar Laboratory; Lab A Reference Range: >23.1 nmol/hr/mg; Lab B Reference Range: 24-56 nmol/hr/mg Reference Range:

5.1-9.2 nmol/hr/mL; AGA: -galactosidase A Patient 1: Multiple data trends sustained up to 22 months Leukocyte + Plasma AGA Enzyme Activity Drug Product VCN: 0.7 Vector Copy Number (VCN) VCN: Vector Copy Number; PBMCs: Peripheral Blood

Mononuclear Cells KIDNEY FUNCTION remains within normal range at 12 mos. CARDIAC FUNCTION remains within normal range at 12 mos. *Source: https://www.kidney.org/atoz/content/gfr mGFR: Measured Glomerular Filtration Rate; eGFR: Estimated Glomerular

Filtration Rate Source: Alfakih K et al, J Magn Reson Imaging, 2003 EF: Ejection Fraction; LV: Left Ventricular mGFR mL/min/1.73 m2 eGFR mL/min/1.73 m2 Baseline Month 12 Normal Range mGFR/eGFR Average 116* mL/min/1.73 m2 Male (20-39 years)

Reference Range Mean Values SD 64.3 4.2% 138.9 24.5 g 67.8 10.7 g/m2 Male (20-39 years) EF (%) LV Mass (Absolute) (g) LV Mass Index (Normalized) (g/m2) Baseline Month 12 Plasma Lyso-Gb3 and Total Gb3 *Reference

Value: 2.4 nM; Reference Value: 4961 nM; 6012 nM before August 2018 (until Day 28 for Patient 1) Lyso-Gb3: Globotriaosylsphingosine; Gb3: Globotriaosylceramide Note: Patient #1 had a skin biopsy score of 3 (severe accumulation) at baseline, a

score of 2 (moderate accumulation) at 6 months and a score of 1 (mild accumulation) at 12 months FAB-201 FABRY PHASE 2 Total Gb3 Lyso-Gb3 Infuse AVR-RD-01 Day 0 Note: Visualization of multiple biomarkers adjusted to utilize the same statistical

scaling ratio across biomarkers (as compared to prior presentation) New data point

Infuse AVR-RD-01 Day 0 Patient 2:

Multiple data trends sustained up to 1 year* Plasma AGA Leukocyte AGA Drug Product VCN: 0.5 VCN: Vector Copy Number; PBMCs: Peripheral Blood Mononuclear Cells *Data from Rupar Laboratory; Reference Range: 24-56 nmol/hr/mg; Reference

Range: 5.1-9.2 nmol/hr/mL; AGA: -galactosidase A KIDNEY FUNCTION remains within normal range mGFR mL/min/1.73 m2 eGFR mL/min/1.73 m2 EF (%) LV Mass (Absolute) (g) LV Mass Index (Normalized) (g/m2) Baseline Month 12 Source:

https://www.kidney.org/atoz/content/gfr mGFR: Measured Glomerular Filtration Rate; eGFR: Estimated Glomerular Filtration Rate Source: Alfakih K et al, J Magn Reson Imaging, 2003 EF: Ejection Fraction; LV: Left Ventricular Reference Range Mean Values

Male 40-49 years 55-65% 58-91 g/m2 Baseline Month 12 Normal Range mGFR/eGFR Average 99 mL/min/1.73 m2 Male (40-49 years) CARDIAC FUNCTION remains within normal range *Reference Value: 2.4 nM; Reference Value: 4961 nM; Note:

Patient #2 has normal substrate, consistent with late-onset cardiac variant phenotype Lyso-Gb3: Globotriaosylsphingosine; Gb3: Globotriaosylceramide Note: As patient #2 is a cardiac variant of Fabry disease, this patient had a skin biopsy score of 0

(trace or no accumulation) at baseline and at 6 months Leukocyte + Plasma AGA Enzyme Activity Vector Copy Number (VCN) Plasma Lyso-Gb3 and Total Gb3 FAB-201 FABRY PHASE 2 - Cardiac Variant Total Gb3 Lyso-Gb3 Note: Visualization of multiple

biomarkers adjusted to utilize the same statistical scaling ratio across biomarkers (as compared to prior presentation) * Latest data points for this patient are at the 1-year follow-up which = 48 weeks per protocol

FAB-201 FABRY PHASE 2 Infuse

AVR-RD-01 Day 0 Drug Product VCN: 1.4 Vector Copy Number (VCN) *Data from Rupar Laboratory; Reference Range: 24-56 nmol/hr/mg; Reference Range: 5.1-9.2 nmol/hr/mL; AGA: -galactosidase A VCN: Vector Copy Number; PBMCs:

Peripheral Blood Mononuclear Cells Plasma Lyso-Gb3 and Total Gb3 Total Gb3 Lyso-Gb3 *Reference Value: 2.4 nM; Reference Value: 4961 nM; Lyso-Gb3: Globotriaosylsphingosine; Gb3: Globotriaosylceramide Infuse AVR-RD-01 Day 0 Infuse AVR-RD-01 Day

0 Skin Biopsy Score (Patient 3) Baseline 2 6 months 2 Plasma AGA Enzyme Activity Patient 3: Data up to 1 year* suggest trend towards durable engraftment Plasma AGA Leukocyte AGA Infuse AVR-RD-01 Day 0 Leukocyte + Plasma AGA Enzyme Activity Patient 1

Patient 2 Patient 3 Reference Range: 5.1-9.2 nmol/hr/mL; AGA: -galactosidase A New data point Note: Visualization of multiple biomarkers adjusted to utilize the same statistical scaling ratio across biomarkers (as compared to prior

presentation) *1-year follow-up = 48 weeks per protocol

Leukocyte AGA (nmol/hr/mg protein)

Plasma AGA (nmol/hr/mL protein) Patient 1 Patient 2 Patient 3 Patient 4 AGA: -Galactosidase A FAB-201 FABRY PHASE 2 Patients 1-4: Plasma and leukocyte enzyme activity sustained up to 22 months Patient #4 dosed using platoTM New data point

New data point Lyso-Gb3:

Globotriaosylsphingosine Note: Patient #2 has normal substrate, consistent with late-onset cardiac variant phenotype Reduction from Baseline to Last Observation Patient 1 88% Patient 2 NA Patient 3 50% Patient 4 43% Patient 1 Patient 2 Patient 3

Patient 4 FAB-201 FABRY PHASE 2 Patients 1-4: Plasma lyso-Gb3 reduction sustained up to 18 months

Two AVR-RD-01 Fabry clinical trials

9 patients dosed across Phases 1 and 2 PHASE 1 Investigator-Sponsored Trial* Patients Patients Key Objectives Key Objectives n = 5 (fully enrolled) On ERT > 6 months prior to enrollment 18-50 year-old males n = 8-12 (4 patients dosed to-date}

Treatment-naive 16 - 50 year-old males Safety and preliminary efficacy Safety and efficacy PHASE 2 AVRO - FAB-201 Trial FAB-201 = AVRO-RD-01-201 Study * Sponsored by FACTs team (Fabry Disease Clinical Research and Therapeutics) in Canada ERT:

Enzyme Replacement Therapy

Gene Tx + Off ERT Gene Tx + ERT ERT

No ERT Gene Tx Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 26% reduction from baseline ERT OFF ERT 18.8 14.0 33.3 10.0 35.7 25.3 26.1 58.5 29.1 15.8 * As of April 27, 2020 (update) Lyso-Gb3: Globotriaosylsphingosine; ERT: Enzyme Replacement

Therapy; Tx: Therapy 47% reduction from baseline ERT ON ERT 43% reduction from baseline ERT OFF ERT 23% increase from baseline ERT OFF ERT 37% reduction from baseline ERT ON ERT Patients 1-5: Plasma lyso-Gb3 reduction sustained up to 32 months All

patients who have discontinued ERT remain off ERT* FABRY PHASE 1

Patient 1 Patient 2 Patient 3

Patient 4 Patient 5 Plasma AGA Activity (nmol/hr/mL) Infuse AVR-RD-01 Day 0 = Leukocyte AGA Activity (nmoles/hr/mg protein) 150 100 50 0 300 250 350 = Infuse AVR-RD-01 Day 0 AGA: -Galactosidase A FABRY PHASE 1 Patients 1-5: Leukocyte and

plasma enzyme activity sustained up to 32 months Consistent trends across all patients, 4 patients > 1 year

Drug Product VCN Patient 1 0.7

Patient 2 1.4 Patient 3 0.8 Patient 4 1.4 Patient 5 1.2 Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 VCN (per cell) Infuse AVR-RD-01 Day 0 Note: 0.1 VCN is indicative of approx. 5-10% of all nucleated cells having an average of 1-2 copies of

the transgene VCN: Vector Copy Number FABRY PHASE 1 VCN stable at 32 months with consistent trend across all other patients 4 patients with 1+ years data

ERT ERT + Gene Therapy Gene Tx Gene

Therapy Normal Kidney Function Mild CKD Moderate CKD Severe CKD No ERT eGFR: Estimated Glomerular Filtration Rate; ERT: Enzyme Replacement Therapy; TX: Therapy; CKD: Chronic Kidney Disease FABRY PHASE 1 Patient 1: Kidney function stable at 32

Anti-AGA antibodies Pre-existing low

titers detected in 4 patients AEs and SAEs reported Phase 1 Fabry (5 patients) and FAB-201 (4 patients) No unexpected safety events or trends identified No SAEs related to AVR-RD-01 drug product Phase 1 AEs (n = 128): Generally consistent with

myeloablative conditioning, underlying disease or pre-existing conditions Phase 1SAEs (n = 2): Febrile neutropenia (grade 3) Thrombophlebitis (grade 2) Note: Safety data cut November 26, 2019 AE: Adverse Event; SAE: Serious Adverse Event NOTE:

AVR-RD-01 is an investigational gene therapy FAB 201 AEs (n = 98): Generally consistent with myeloablative conditioning, underlying disease or pre-existing conditions Grade 1 or 2 (n = 72) Grade 3 or 4 (n = 30) FAB 201 SAEs: (n = 4) Pre-treatment

and prior to conditioning Seizure (grade 2) Post-treatment Dehydration, nausea, vomiting (grade 3) Febrile neutropenia (2 patients, grade 3 & 4)

Cystinosis AVR-RD-04

Goals for gene therapy in cystinosis

UNMET NEEDS: Kidney function Unmet needs: renal Fanconi syndrome, proteinuria, chronic kidney disease, kidney failure Vision Unmet needs: corneal cystine accumulation, photophobia, involuntary eyelid closure CNS complications Unmet needs: myopathy,

hypotonia, tremors, difficulty swallowing, neurodevelopmental issues (speech and walking delay and cognitive impairment) Endocrine disorders Unmet needs: softening/weakening of bones, bone pain, rickets, long bone deformations, hypophosphatemia,

delayed growth, hypothyroidism, pancreatic insulin insufficiency, diabetes, infertility Everyday burden of illness and life expectancy Unmet needs: medications multiple times per day that cause GI discomfort and sulfur body and breath smell,

shortened lifespan Sources: Ariceta G et al, Nephrol Dial Transplant, 2015; Elmonem M et al, Orphanet Journal of Rare Diseases, 2016; Gahl et al, NEJM, 2002; Bois et al, J Med Genet, 1976 CNS: Central Nervous System; GI: Gastrointestinal