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STAINES-UPON-THAMES, United Kingdom, April 12, 2019 /PRNewswire/ -- Mallinckrodt plc (NYSE: MNK), a leading global specialty pharmaceutical company, today announced that Stratatech, a Mallinckrodt company, has completed patient enrollment in its ongoing pivotal Phase 3 clinical trial of StrataGraft^®, an investigational regenerative skin tissue. The multicenter study is evaluating the efficacy and safety of StrataGraft in the promotion of autologous skin regeneration of complex skin defects due to severe thermal burns that contain intact dermal elements (also known as deep partial-thickness burns). The safety and effectiveness of StrataGraft have not yet been established by the U.S. Food and Drug Administration (FDA). Investigators enrolled 71 patients across 12 clinical sites.

"This is an exciting milestone for StrataGraft, an investigational therapy that has the potential to revolutionize the standard of care for patients with severe burns," said Steven Romano, M.D., Executive Vice President and Chief Scientific Officer at Mallinckrodt. "We believe that StrataGraft, if approved, will advance the treatment of these severe injuries by providing patients with an alternative to autograft."

Autograft, the current standard of care, involves surgically removing a sheet of healthy skin from an uninjured site on the patient and using it to cover the original burn wound. Patients and clinicians report significant morbidity associated with the resulting donor site wounds, which are created during surgical removal of healthy skin. Donor site wounds are extremely painful, and can create risks of additional scarring and infection.

As a result of achieving this important enrollment milestone, Mallinckrodt expects top-line data to be available by the end of 2019, following collection of follow-up data on the study's co-primary endpoints. The company anticipates submitting a Biologics License Application (BLA) in 2020 with the FDA if data from the Phase 3 trial of StrataGraft regenerative skin tissue are supportive. The FDA has granted StrataGraft orphan drug status, and it was also among the first products designated by the Agency as a Regenerative Medicine Advanced Therapy under the provisions of the 21st Century Cures Act.

About the Phase 3 Clinical Trial
The open-label, controlled, randomized Phase 3 trial is evaluating the efficacy and safety of StrataGraft in promoting autologous skin tissue regeneration of complex skin defects due to thermal burns. The trial is fully enrolled, and all study participants are ages 18 years and older with 3 to 49 percent total body surface area complex skin defects caused by thermal burns that contain intact dermal elements for which surgical excision and autografts are clinically indicated. The study design uses a within-patient control, with two sites randomly assigned to either standard of care (autograft) or StrataGraft treatment.

The trial's primary endpoints include:

• Autograft sparing, measured as the difference in the percent area of the StrataGraft treatment site and the control autograft treatment site, that is autografted by three months; and
• Durable wound closure, measured as the proportion of study participants achieving durable wound closure of the StrataGraft treatment site at three months without subsequent autograft placement.

For more information about the Phase 3 trial, visit www.clinicaltrials.gov (identifier: NCT03005106).

About StrataGraft Regenerative Skin Tissue
StrataGraft is an engineered, bilayer human skin substitute in development for patients with severe burns or other complex skin defects. Designed to mimic natural human skin with both inner dermis-like and outer epidermis-like layers, StrataGraft is being developed to be sutured, stapled or secured with an adhesive and initially provide coverage during the wound healing process. StrataGraft tissues are cryopreserved in order to deliver viable cells upon application.

StrataGraft regenerative skin tissue is produced using Near-Diploid Immortal Keratinocytes (NIKS^®) cells and human dermal fibroblasts grown in accordance with Good Manufacturing Practice. StrataGraft tissue, as well as the NIKS cells and dermal fibroblasts, have been thoroughly characterized, helping to ensure consistent delivery of tissue that is virus-free, non-tumorigenic, and consistent genetically batch to batch. StrataGraft is an investigational product. The safety and effectiveness of StrataGraft have not yet been established by FDA.

In addition to the current Phase 3 trial, the company is evaluating StrataGraft in an ongoing Phase 2 trial for the treatment of adults with full-thickness complex skin defects resulting from burns and select other etiologies. There are also plans to study the safety and efficacy of StrataGraft in pediatric populations.

Funding and technical support for the development of StrataGraft regenerative skin tissue is being provided by the Biomedical Advanced Research and Development Authority (BARDA), under the Assistant Secretary for Preparedness and Response, within the U.S. Department of Health and Human Services, under Project BioShield Contract No. HHSO100201500027C. These efforts are part of BARDA's strategy to build emergency preparedness in response to mass casualty events involving trauma and thermal burns by developing novel medical countermeasures for adult and pediatric populations. In the case of a mass casualty thermal burn event, the Government Accountability Office estimates that more than 10,000 patients might require thermal burn care.¹ The limited number of specialized burn centers and related medical infrastructure in the U.S. creates a public health need for therapies that could be deployed quickly for use in these and other care sites.

About Serious Thermal Burns Containing Intact Dermal Elements
Serious thermal burns containing intact dermal elements, also known as deep partial-thickness burns, are complex skin injuries in which the entire epidermis and more than two thirds of the dermis are destroyed.

Current standard of care for severe complex skin wounds involves the surgical harvesting of healthy skin tissue from an uninjured site on the patient and transplanting the autologous skin graft to the injury. While this process can be effective in providing closure of the original wound, it has significant limitations related to the donor site wounds created during surgical removal of autologous skin tissue for grafting. Donor site wounds are extremely painful and can create risks of additional scarring and infection. In addition, the amount of healthy skin available for harvesting is frequently limited in large burns, necessitating sequential re-harvesting of available donor sites. As a result, there is an urgent need for alternatives to donor site harvesting for treatment of severe burns and other complex skin defects.

About Mallinckrodt
Mallinckrodt is a global business consisting of multiple wholly owned subsidiaries that develop, manufacture, market and distribute specialty pharmaceutical products and therapies. The company's Specialty Brands reportable segment's areas of focus include autoimmune and rare diseases in specialty areas like neurology, rheumatology, nephrology, pulmonology and ophthalmology; immunotherapy and neonatal respiratory critical care therapies; and analgesics. Its Specialty Generics and Amitiza reportable segment includes specialty generic drugs, active pharmaceutical ingredients and AMITIZA^® (lubiprostone). To learn more about Mallinckrodt, visit www.mallinckrodt.com.

Mallinckrodt uses its website as a channel of distribution of important company information, such as press releases, investor presentations and other financial information. It also uses its website to expedite public access to time-critical information regarding the company in advance of or in lieu of distributing a press release or a filing with the U.S. Securities and Exchange Commission (SEC) disclosing the same information. Therefore, investors should look to the Investor Relations page of the website for important and time-critical information. Visitors to the website can also register to receive automatic e-mail and other notifications alerting them when new information is made available on the Investor Relations page of the website.

CAUTIONARY STATEMENTS RELATED TO FORWARD-LOOKING STATEMENTS
This release includes forward-looking statements concerning StrataGraft regenerative skin tissue, including expectations with regard to related clinical data and regulatory filings, its potential impact on patients and anticipated benefits associated with its use. The statements are based on assumptions about many important factors, including the following, which could cause actual results to differ materially from those in the forward-looking statements: clinical trial results; satisfaction of regulatory and other requirements; actions of regulatory bodies and other governmental authorities; changes in laws and regulations; issues with product quality, manufacturing or supply, or patient safety issues; and other risks identified and described in more detail in the "Risk Factors" section of Mallinckrodt's most recent Annual Report on Form 10-K and other filings with the SEC, all of which are available on its website. The forward-looking statements made herein speak only as of the date hereof and Mallinckrodt does not assume any obligation to update or revise any forward-looking statement, whether as a result of new information, future events and developments or otherwise, except as required by law.

CONTACTS
Investor Relations
Daniel J. Speciale, CPA
Vice President, Investor Relations and IRO
314-654-3638
daniel.speciale@mnk.com

Media
Daniel Yunger
Kekst CNC
212-521-4879
mallinckrodt@kekstcnc.com

Mallinckrodt, the "M" brand mark and the Mallinckrodt Pharmaceuticals logo are trademarks of a Mallinckrodt company. Other brands are trademarks of a Mallinckrodt company or their respective owners. © 2019 Mallinckrodt. US-1900506 4/19

¹https://www.gao.gov/assets/590/588738.pdf. Accessed April 4, 2019.

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SOURCE Mallinckrodt plc