Avrobio, Magenta team up to test targeted antibody-drug conjugate for lentiviral gene therapies

Collaboration focuses on advancing innovation with antibody-drug conjugate (ADC)-based conditioning for lentiviral gene therapies

Under the collaboration, AVROBIO and Magenta will jointly evaluate MGTA-117 in conjunction with one or more of AVROBIO’s investigational gene therapies

Each company will retain all commercial rights to their respective programs

CAMBRIDGE, Mass.–(BUSINESS WIRE)–$AVRO—AVROBIO, Inc. (Nasdaq: AVRO) and Magenta Therapeutics (Nasdaq: MGTA) today announced a research and clinical collaboration agreement to evaluate the potential utility of MGTA-117, Magenta’s novel targeted antibody-drug conjugate (ADC) for conditioning patients before they receive one of AVROBIO’s investigational lentiviral gene therapies.

The collaboration will combine AVROBIO’s leadership in lentiviral gene therapies with Magenta’s expertise in ADC-based conditioning and is expected to further the two companies’ shared mission to enable patients to live free from disease. Under the collaboration, AVROBIO and Magenta will jointly evaluate MGTA-117 in conjunction with one or more of AVROBIO’s investigational gene therapies. Magenta will retain all commercial rights to MGTA-117. AVROBIO will retain all commercial rights to its gene therapies and will be responsible for the clinical trial costs related to the evaluation of MGTA-117 with AVROBIO’s gene therapies.

“This agreement with Magenta springs from our strategic focus on maintaining technology leadership in gene therapy,” said Geoff MacKay, AVROBIO’s president and CEO. “AVROBIO has always led by investing early in technological innovations that further the field of lentiviral gene therapy, such as plato™, our proprietary platform designed to optimize the safety, potency and durability of our investigational lentiviral gene therapies. We’re continually assessing new technologies that could be complementary to our plato platform to sustain our cutting-edge advantage and continue to evolve plato’s capabilities.”

“We believe targeted ADCs represent the next generation of medicines to prepare patients for gene therapy or transplant in a targeted, precise way. AVROBIO’s investigational gene therapies complement our platform as well as our focus and commitment to patients. This partnership will allow Magenta to validate our conditioning platform in lentiviral gene therapy applications,” said Jason Gardner, D.Phil., president and chief executive officer, Magenta Therapeutics. “We’ve selected ADCs as the preferred modality for our conditioning programs, as we believe they offer the most promising option for more patients. We have optimized our ADCs for gene therapy and transplant settings and look forward to collaborating with AVROBIO to evaluate MGTA-117 in specific gene therapy settings. Magenta will continue to develop MGTA-117 in other diseases, including blood cancers and genetic diseases.”

MGTA-117, Magenta’s most advanced conditioning program, is a CD117-targeted antibody engineered for the transplant setting and conjugated to amanitin, a toxin in-licensed from Heidelberg Pharma. It is designed to precisely deplete only hematopoietic stem and progenitor cells and has shown high selectivity, potent efficacy, wide safety margins and broad tolerability in non-human primate models, suggesting that it may be capable of clearing space in bone marrow to support long-term engraftment and rapid recovery in humans. Magenta plans to complete IND-enabling studies this year.

AVROBIO currently uses a personalized conditioning regimen with precision dosing of busulfan, an extensively validated conditioning agent generally considered to be the gold standard for ex vivo lentiviral gene therapy, based on decades of general use and administration to hundreds of patients treated with lentiviral gene therapy candidates. The treating clinician uses therapeutic drug monitoring (TDM) to evaluate how quickly the patient metabolizes busulfan and adjusts the dose regimen accordingly with the goal of achieving the optimum result. AVROBIO has reported early clinical data with this precision conditioning regimen with TDM in its own clinical trials, adding to a body of data that suggest busulfan can effectively clear space in the patient’s bone marrow, where stem cells engraft, produce generations of daughter cells carrying the therapeutic gene and make the functional protein the patient needs to maintain cellular health.

About AVROBIO

Our mission is to free people from a lifetime of genetic disease with a single dose of gene therapy. We aim to halt or reverse disease throughout the body by driving durable expression of functional protein, even in hard-to-reach tissues and organs including the brain, muscle and bone. Our clinical-stage programs include Fabry disease, Gaucher disease and cystinosis and we also are advancing a program in Pompe disease. AVROBIO is powered by the plato™ gene therapy platform, our foundation designed to scale gene therapy worldwide. We are headquartered in Cambridge, Mass., with an office in Toronto, Ontario. For additional information, visit avrobio.com, and follow us on Twitter and LinkedIn.

About Magenta Therapeutics

Magenta Therapeutics is a clinical-stage biotechnology company developing medicines to bring the curative power of immune system reset through stem cell transplant to more patients with autoimmune diseases, genetic diseases and blood cancers. Magenta is combining leadership in stem cell biology and biotherapeutics development with clinical and regulatory expertise, a unique business model and broad networks in the stem cell transplant world to revolutionize immune reset for more patients. Magenta is based in Cambridge, Mass. For more information, please visit www.magentatx.com. Follow Magenta on Twitter: @magentatx.

AVROBIO Forward-Looking Statements

This press release contains forward-looking statements, including 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 for and the potential therapeutic benefits of our prospective product candidates, the design, commencement, enrollment and timing of ongoing or planned clinical trials, clinical trial results, product approvals and regulatory pathways, anticipated benefits of our gene therapy platform including potential impact on our commercialization activities, timing and likelihood of success, the expected benefits and results of our implementation of the plato platform in our clinical trials and gene therapy programs, the expected safety profile of our investigational gene therapies, and the potential and expected benefits of MGTA-117, Magenta’s investigational antibody-drug conjugate, including the ability of MGTA-117 to deplete hematopoietic stem and progenitor cells in order to clear space in bone marrow to support long-term engraftment in humans, as well as MGTA-117’s potential application to AVROBIO’s investigational gene therapies. Any such statements in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Results in preclinical or early-stage clinical trials may not be indicative of results from later stage or larger scale clinical trials and do not ensure regulatory approval. You should not place undue reliance on these statements, or the scientific data presented.

Any forward-looking statements in this press release are based on AVROBIO’s current expectations, estimates and projections about our industry as well as management’s current beliefs and expectations of future events only as of today and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, the risk that any one or more of AVROBIO’s product candidates 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, the risk that AVROBIO may not successfully recruit or enroll a sufficient number of patients for our 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 MGTA-117 with respect to AVROBIO’s investigational gene therapies, the risk that our product candidates 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 product candidates, the risk that we will be unable to obtain and maintain regulatory approval for our product candidates, the risk that the size and growth potential of the market for our product candidates 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 product candidates. 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 materially and adversely from those contained in the forward-looking statements, see the section entitled “Risk Factors” in AVROBIO’s most recent Annual or Quarterly Report, 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.

Magenta Therapeutics Forward Looking Statements

This press release may contain forward-looking statements and information within the meaning of The Private Securities Litigation Reform Act of 1995 and other federal securities laws, including, without limitation, statements regarding the research and clinical collaboration agreement between Magenta and AVROBIO, including the timing, progress and success of the collaboration contemplated under the agreement, the successful evaluation MGTA-117 in conjunction with one or more of AVROBIO’s investigational gene therapies under the agreement, the anticipated cost allocation and other commercial terms under the agreement, Magenta’s strategy and business plan, as well as the future development, manufacture and commercialization between AVROBIO and Magenta. The use of words such as “may,” “will,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “seeks,” “endeavor,” “potential,” “continue” or the negative of such words or other similar expressions can be used to identify forward-looking statements. The express or implied forward-looking statements included in this press release are only predictions and are subject to a number of risks, uncertainties and assumptions, including, without limitation, risks set forth under the caption “Risk Factors” in Magenta’s most recent Annual Report on Form 10-K, as updated by Magenta’s most recent Quarterly Report on Form 10-Q and its other filings with the Securities and Exchange Commission, as well as risks, uncertainties and assumptions regarding the impact of the COVID-19 pandemic to Magenta’s business, operations, strategy, goals and anticipated timelines, including, without limitation, Magenta’s ongoing and planned preclinical activities, ability to initiate, enroll, conduct or complete ongoing and planned clinical trials, timelines for regulatory submissions and financial position. In light of these risks, uncertainties and assumptions, the forward-looking events and circumstances discussed in this press release may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements. You should not rely upon forward-looking statements as predictions of future events. Although Magenta believes that the expectations reflected in the forward-looking statements are reasonable, it cannot guarantee that the future results, levels of activity, performance or events and circumstances reflected in the forward-looking statements will be achieved or occur. Moreover, except as required by law, neither Magenta nor any other person assumes responsibility for the accuracy and completeness of the forward-looking statements included in this press release. Any forward-looking statement included in this press release speaks only as of the date on which it was made. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law.

Contacts

AVROBIO
Investor Contact:
Christopher F. Brinzey

Westwicke, an ICR Company

339-970-2843

[email protected]

Media Contact:
Tom Donovan

Ten Bridge Communications

857-559-3397

[email protected]

Magenta Therapeutics:
Manisha Pai, Vice President, Communications & Investor Relations

617-510-9193

[email protected]

Lyndsey Scull, Director, Corporate Communications

202-213-7086

[email protected]