Mallinckrodt Announces Interim Analysis Results for Therakos(R) Platform Phase 3 Clinical Trial in Treatment of Pediatric Patients with Steroid Refractory…

— Overall response rate exceeded specified study midpoint target (n=25); company elects to discontinue further patient enrollment as allowed by protocol —

Mallinckrodt plc (NYSE:MNK), a leading global specialty pharmaceutical company, today announced interim analysis results of its company-sponsored, Phase 3, single-arm, open-label, multi-center study assessing the efficacy of treating steroid-refractory, acute Graft-versus-Host Disease (aGvHD) in pediatric patients with the Therakos(R) Photopheresis platform in conjunction with liquid methoxsalen. Given the overall response rate exceeded the specified target at the study midpoint, the company is electing not to proceed with further enrollment of additional patients in the clinical trial.

The planned interim analysis occurred at the midway point of enrollment (n=25) when pediatric patients (ages 1-21 years) reached four weeks of therapy to assess response rates. The analysis found an overall response rate of 74%. The company also performed an ad hoc 12-week analysis showing an overall response rate of 48%. The study protocol allows for discontinuation of the study if the treatment overall response rate at the four-week interim analysis is at least 48%. Eleven serious adverse events were reported, leading to two subject withdrawals and two deaths; none were considered related to the Therakos photopheresis therapy. The safety and effectiveness of THERAKOS CELLEX Photopheresis System for use in treating pediatric patients with steroid-refractory aGvHD has not been evaluated by any regulatory body.

“Mallinckrodt is pleased to have been able to partner with the pediatric transplant community concerning this fragile patient population,” said Steven Romano, M.D., Executive Vice President and Chief Scientific Officer, Mallinckrodt. “We believe the full details from the study’s interim analysis — which will be made public — will make a meaningful contribution to the body of data related to this critical condition.”

More details on the study (NCT02524847) can be found here on http://www.clinicaltrials.gov.

About Therakos Immunotherapy

Therakos immunotherapy is delivered through CELLEX systems to harness the power of the patient’s immune system to treat the skin manifestations of CTCL, and is used by academic medical centers, hospitals, and treatment centers in more than 25 countries. Therakos photopheresis systems are fully integrated closed systems indicated for the administration of photopheresis.

CAUTION: READ THE THERAKOS UVAR XTS or THERAKOS CELLEX PHOTOPHERESIS

SYSTEMS’ OPERATOR’S MANUAL PRIOR TO PRESCRIBING OR DISPENSING THIS MEDICATION.

For the THERAKOS(R) UVAR XTS(R)/CELLEX(R) Photopheresis Procedure:

INDICATIONS

The THERAKOS(TM) UVAR XTS(TM) and THERAKOS(TM) CELLEX(TM) Photopheresis Systems are indicated for the administration of photopheresis.

IMPORTANT SAFETY INFORMATION

Contraindications

THERAKOS(TM) Photopheresis is contraindicated in patients possessing a specific history of a light sensitive disease. THERAKOS(TM) Photopheresis is contraindicated in patients who cannot tolerate extracorporeal volume loss or who have white blood cell counts greater than 25,000 mm3. THERAKOS(TM) Photopheresis is contraindicated in patients who have coagulation disorders or who have previously had a splenectomy.

Warnings and Precautions

THERAKOS(TM) Photopheresis treatments should always be performed in locations where standard medical emergency equipment is available. Volume replacement fluids and/or volume expanders should be readily available throughout the procedure. Both men and women should take adequate contraceptive precautions both during and after completion of photopheresis therapy. Safety in children has not been established.

Adverse Events

— Hypotension may occur during any treatment involving extracorporeal

circulation. Closely monitor the patient during the entire treatment

for hypotension.

— Transient pyretic reactions, 37.7-38.9 degrees C (100-102 degrees F),

have been observed in some patients within six to eight hours of

reinfusion of the photoactivated leukocyte-enriched blood. A

temporary increase in erythroderma may accompany the pyretic

reaction.

— Treatment frequency exceeding labelling recommendations may result in

anaemia.

— Venous access carries a small risk of infection and pain.

Please see the appropriate THERAKOS Photopheresis System Operator’s Manual for full product information.

ABOUT MALLINCKRODT

Mallinckrodt is a global business that develops, manufactures, markets and distributes specialty pharmaceutical products and therapies. 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; analgesics and gastrointestinal products.

/Public Release.