Press Release: Shire, New River Pharmaceuticals Announce FDA Approval of VYVANSE

Shire Pharmaceuticals and New River Pharmaceuticals Announce FDA Approval of The First and Only Stimulant Prodrug VYVANSE(TM) as a Novel Treatment for ADHD Basingstoke, U.K., Philadelphia, PA and Radford, VA – FEBRUARY 23, 2007 – Shire plc and its collaborative partner New River Pharmaceuticals Inc. announced today that the U.S. Food and Drug Administration (FDA) has granted marketing approval for VYVANSE (lisdexamfetamine dimesylate, formerly known as NRP104), for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). On February 20, 2007 Shire and New River announced an agreement whereby Shire will acquire New River for approximately $2.6 billion in an all cash transaction unanimously recommended by the Boards of both companies. The transaction is the subject of another press release issued February 20, 2007. VYVANSE is a prodrug that is therapeutically inactive until metabolized in the body. In clinical studies designed to measure duration of effect, VYVANSE provided significant efficacy compared to placebo for a full treatment day, up through and including 6:00 pm. Furthermore, when VYVANSE was administered orally and intravenously in two clinical human drug abuse studies, VYVANSE produced subjective responses on a scale of “Drug Liking Effects” (DLE) that were less than d-amphetamine at equivalent doses. DLE is used in clinical abuse studies to measure relative preference among known substance abusers. “The FDA approval of VYVANSE is exciting news for Shire as well as for patients, their families, and healthcare providers as it’s an important, novel approach for the treatment of ADHD,” said Matthew Emmens, Shire Chief Executive Officer. “The label we received with the approval letter includes information about the extended duration of effect and abuse-related drug liking characteristics of VYVANSE which illustrate benefits that differentiate this compound from other ADHD medicines. The addition of VYVANSE to our ADHD portfolio reaffirms Shire’s commitment to continue to address unmet medical needs and advance the science of ADHD treatment. Beginning with product launch in Q2 2007, Shire will make VYVANSE our top promotional priority within our ADHD portfolio.” Randal J. Kirk, New River’s Chairman and Chief Executive Officer, remarked, “VYVANSE’s approval signals a new era in the treatment of ADHD. Upon product launch, patients will have a novel treatment option combining the effectiveness of a stimulant – long considered the gold standard in ADHD medicines – with other potential benefits.” The FDA has proposed that VYVANSE be classified as a Schedule II controlled substance. This proposal was submitted to and accepted by the U.S. Drug Enforcement Administration (DEA). A final scheduling decision is expected from the DEA following a 30-day period for public comment. Once VYVANSE receives final scheduling designation, the label will be available. Pending final scheduling designation, product launch is anticipated in Q2 2007. VYVANSE will be available in three dosage strengths: 30 mg, 50 mg and 70 mg, all indicated for once-daily dosing.1 New River developed VYVANSE as a new ADHD medication designed to provide lower potential for abuse, in which d-amphetamine is covalently linked to l-lysine, a naturally occurring amino acid. The combination is rapidly absorbed from the gastrointestinal tract and converted to d-amphetamine, which is responsible for VYVANSE’s activity. Joseph Biederman, MD, director of Pediatric Psychopharmacology at Massachusetts General Hospital, was lead investigator on the pivotal clinical studies testing lisdexamfetamine dimesylate for the treatment of ADHD. These large multi-site studies showed that the drug significantly reduced ADHD symptoms throughout the day with a predictable tolerability profile. “Our studies showed that this next-generation stimulant medication's unique chemical profile offers an option for physicians and their patients in the treatment of ADHD, with outstanding efficacy and duration of action” said Dr. Biederman. Additional information about VYVANSE and other Shire treatments for ADHD is available at www.ShireADHDTreatments.com. VYVANSE Significantly Controls ADHD Symptoms Data from phase II and phase III clinical trials demonstrated statistically significant improvements in ADHD symptoms for patients aged 6 to 12 years treated with VYVANSE compared to patients treated with placebo. These studies demonstrated that all doses of VYVANSE (30 mg, 50 mg and 70 mg) provided significant efficacy at all time points tested, including 6pm.2 In the phase II, analog classroom study, patients demonstrated significantly improved behavior when receiving either VYVANSE or ADDERALL XR® (mixed salts of a single-entity amphetamine product) as measured by the Swanson, Kotkin, Agler, M. Flynn and Pelham (SKAMP) deportment rating scale, a standardized, validated classroom assessment tool used for evaluating the behavioral symptoms of ADHD.3 Both treatments resulted in significantly improved behavior versus a placebo (P <.0001 for both patients also demonstrated significantly improved academic productivity with treatments compared to placebo medications as measured by permanent product measure of performance an age-adjusted collection math problems that measures a child ability pay attention and stay on task increase in the number attempted successfully completed problems.4 phase iii randomized double-blind placebo-controlled study all three doses vyvanse significant improvements adhd rating scale scores after four weeks once-daily treatment. adhd-rs-iv is standardized validated test assessing symptoms children their response treatment.6 this which contains items based diagnostic criteria defined apa statistical manual mental disorders fourth edition text revision publication american psychiatric association. additionally presented october at major scientific meeting yielded percent improvement primary aged years who received six months treatment open-label study. results taking produced or much clinical global impressions score.9 about adderall xr tell your doctor any heart conditions including structural abnormalities you family member may have. inform immediately if develops suggest such chest pain fainting. should not be taken have advanced disease blood vessels symptomatic moderate severe high pressure overactive thyroid gland known allergy unusual reactions drugs called sympathomimetic amines example pseudoephedrine seizures glaucoma history alcohol agitated states monoamine oxidase inhibitor within last days. before using are being treated depression worthlessness hopelessness bipolar disorder abnormal thoughts visions hear sounds been diagnosed psychosis had eegs exhibit aggressive behavior hostility. these develop while xr. abuse amphetamines lead dependence. misuse amphetamine cause sudden death serious cardiovascular adverse events. events reported rarely use. were generally well tolerated studies. most common side effects studies included: decreased appetite difficulty falling asleep stomachache irritability. emotional lability adolescents loss weight adults dry mouth headache loss. aggression new mania growth suppression worsening motion verbal tics tourette syndrome associated use type. blurred vision collaboration agreement january river pharmaceuticals signed collaborative shire commercialize vyvanse. details available previous filings u.s. securities exchange commission. planned acquisition additional information tender offer described press release has yet commenced neither purchase nor solicitation sell stock. investors security holders urged read statement regarding report when they become because will contain important information. filed subsidiary commission sec. obtain free copy statements other documents sec website maintained www.sec.gov. related materials obtained directing requests hampshire international business park chineham basingstoke england rg24 attention: investor relations. grove avenue radford virginia director corporate communications.>