• Study addresses key U.S. Food and Drug Administration (FDA) requirement, keeping SHP465 on track for potential 2017 U.S. launch

• Topline data revealed SHP465 met primary endpoint, showing ADHD symptom improvement in children and adolescents (p<0.001)

• Key secondary endpoint also met, showing higher proportion of patients were rated improved (p<0.001)

• Data add to overall robust clinical development program for SHP465

LEXINGTON, MA, USA I April 4, 2016 I Shire plc (LSE: SHP, NASDAQ: SHPG) today announces positive topline results from a four-week Phase 3, randomized, double-blind, multi-center, placebo-controlled, dose-optimization, safety and efficacy study, SHP465-305, in children and adolescents aged 6-17 years with Attention-Deficit/Hyperactivity Disorder (ADHD). SHP465 (triple-bead mixed amphetamine salts – MAS) is an investigational oral stimulant medication being evaluated in the U.S. as a potential treatment for ADHD, a therapeutic area with significant need for additional treatment options.

The primary efficacy analysis of study 305 demonstrated that SHP465, administered as a daily morning dose, was superior to placebo on the change from baseline in ADHD-RS-IV (ADHD rating scale) total score, with a Least Squares (LS) mean difference from placebo at Week 4 of -9.9 (95% CI: -13.0 to -6.8, p<0.001), suggesting a significant improvement in ADHD symptoms. SHP465 was also superior to placebo in the key secondary efficacy analysis on the clinical global impression improvement scale (CGI-I), with an LS mean difference from placebo at Week 4 of -0.8 (95% CI: -1.1 to -0.5, p<0.001), indicating a significantly higher proportion of patients were rated improved on the CGI-I rating scale. The CGI-I is a standardized assessment tool that allows clinicians to rate the severity of ADHD illness, change over time and efficacy of medication.

Treatment-emergent adverse events ≥ 5% for SHP 465-305 were decreased appetite, headache, insomnia, irritability, nausea, weight decrease and dizziness. Adverse events were generally mild to moderate in severity and similar to those observed in previous SHP465 studies and with other amphetamine compounds.

The completion of SHP465-305 addresses an FDA requirement to evaluate the safety and efficacy of SHP465 in children and adolescents prior to filing a Class 2 resubmission of the medicine for FDA approval.

“We are pleased with the positive results of the SHP465-305 study,” said Philip J. Vickers, Ph.D., Head of Research & Development, Shire. “These results represent an important step toward a new treatment option for patients with ADHD. Shire looks forward to including these data as part of the FDA resubmission and is eager to continue advancing this clinical program.”

Dr. Matthew Brams, M.D., Clinical Assistant Professor at Baylor College of Medicine and principal investigator for study 305, added: “The study of SHP465 in children and adolescents is an essential next step to progressing the clinical program. I’m excited about these positive data from SHP465-305 because of the benefit that this potential new treatment option may provide for patients with ADHD.”

Overall Robust SHP465 Clinical Development Program to Support Class 2 Resubmission

Including study 305 and previous studies, Shire now has a robust database of 15 clinical studies evaluating SHP465 in more than 1,100 subjects. Once the pharmacokinetic study and an additional safety and efficacy Phase 3 trial in adults currently under way are complete later this year, Shire plans to add these study results to its existing SHP465 data set to submit a Class 2 resubmission for FDA approval of the medicine for treatment of ADHD. SHP465 remains on track for potential U.S. launch in the second half of 2017.

In previous adolescent and adult clinical studies, SHP465 demonstrated a statistically significant difference versus placebo at 16 hours post dosing, with onset of action starting 4 hours post dosing, as measured by the Permanent Product Measure of Performance (PERMP). PERMP was not measured in the SHP465-305 study.

Protection for Shire’s ADHD Franchise Extends to 2029

There are patents supporting Shire’s overall ADHD franchise in the U.S. that extend to 2029. With a launch planned for the second half of 2017, Shire expects that SHP465, following potential FDA approval, will have three years of Hatch-Waxman exclusivity and at least three patents listed in the FDA Orange Book expiring as late as May 2029.

NOTES TO EDITORS

Shire enables people with life-altering conditions to lead better lives.

Our strategy is to focus on developing and marketing innovative specialty medicines to meet significant unmet patient needs.

We focus on providing treatments in Rare Diseases, Neuroscience, Gastrointestinal and Internal Medicine and we are developing treatments for symptomatic conditions treated by specialist physicians in other targeted therapeutic areas, such as Ophthalmics.

SOURCE: Shire