GlaxoSmithKline and Adolor Present Positive Results from a Clinical Study of Alvimopan (Entereg(R))

Patients Report Statistically Significant Improvement inOpioid-Induced Gastrointestinal Side Effects and Health-RelatedQuality of Life in Phase 2b Entereg Trial

GlaxoSmithKline (LSE and NYSE:GSK) and Adolor Corporation(NASDAQ:ADLR) today presented at the American Pain Society Meeting inSan Antonio, Texas, positive results from a Phase 2b clinical study ofalvimopan (Entereg), an orally administered investigational drug thatblocks peripheral mu-opioid receptors.(1) In this large study,evaluating alvimopan for the treatment of opioid-inducedgastrointestinal side effects, patients reported a significantimprovement in common and bothersome gastrointestinal (GI) symptomsassociated with opioid use, including constipation, abdominal pain andbloating.

"Millions of people worldwide take opioids chronically to treatmoderate to severe pain and about half of them will suffer fromassociated constipation, abdominal pain, discomfort and bloating.(2)Constipation can lead to serious complications and in some cases canbe life threatening. Often patients cannot receive enough opioid tomanage their pain due to constipation. The findings from this studysuggest that alvimopan may play an important role in treating these GIside effects in patients by blocking the effects opioids have on thegut without adversely impacting the effect on pain control," said Dr.Lynn Webster, Lifetree Clinical Research and Pain Clinic, Salt LakeCity, Utah, USA.

This large double-blind study (SB-767905/011) randomized 522patients taking opioids for persistent non-cancer pain to:

-- alvimopan 0.5mg twice a day (BID) (group 1) or

-- alvimopan 1mg once a day (QD) (group 2) or

-- alvimopan 1mg twice a day (BID) (group 3) or

-- placebo

for 6 weeks. The average increase in spontaneous bowel movements(defined as a bowel movement in the absence of laxatives within theprevious 24 hours) per week was approximately:

-- 3.5 in groups 1 and 2 (p less than 0.001) and

-- 4.3 in group 3 (p less than 0.001) compared with

-- 1.7 in placebo group

The increase in spontaneous bowel movements for each alvimopandose group was double that of placebo, became apparent within 1 weekand was sustained throughout the 6-week treatment period, returningtowards baseline promptly after discontinuation of study therapy.

All groups reported an average frequency of 1 spontaneous bowelmovement a week at baseline. During treatment, 63-68% ofalvimopan-treated patients reported 3 or more spontaneous bowelmovements a week, compared with 39% receiving placebo. In addition toseeing improvements in typical measures of constipation (reduction instraining, improved stool consistency, and greater frequency ofcomplete evacuation), patients taking alvimopan also showedimprovements in other measures of GI function such as abdominal painand bloating.

The most common adverse events reported in the trial wereabdominal pain, nausea and diarrhea. The frequency of these adverseevents was similar between placebo and alvimopan treated patients atthe 0.5mg BID dose. There was an increase in frequency at the 1mg doseof alvimopan for the three most common adverse events.

The baseline characteristics and opioid induced GI symptoms of the522 patients who were enrolled into the study were also reported atthe meeting. The patients, on average, were approximately 50 yearsold, and had taken opioids for more than 6 years for variousconditions, including back pain (58%), neuralgia (42%), fibromyalgia(8%) and arthritis (7%). Despite 80% of patients reporting use oflaxatives and/or stool softeners, those entering the study reportedtypical constipation symptoms including, straining (83%), hard stools(87%) and incomplete evacuation (87%). Other GI symptoms reportedconsistently were bloating (79%), discomfort (80%) and abdominal pain(65%).(3)

The effect of alvimopan on the health-related quality of life(HRQOL) of patients in the study was also reported at the meeting.HRQOL was assessed using the Patient Assessment of ConstipationQuality of Life (PAC-QOL) instrument, which consists of 28 questionson physical discomfort (4 questions), psychosocial discomfort (8questions), worries/concerns (11 questions) and satisfaction (5questions). At baseline the patients' scores, ranging from 1.87 to2.1, indicated that their HRQOL was moderately impaired. Alvimopansignificantly improved PAC-QOL total scores after 6 weeks in alltreatment groups compared with placebo (p less than 0.02). Changes inoverall scores from baseline to week 6 were 2 to 1.61 for placebo, 1.9to 1.27 for alvimopan 0.5mg twice a day, 1.87 to 1.26 for alvimopan1mg once a day, and 2.1 to 1.33 for alvimopan 1mg twice a day.Statistically significant improvements were observed on thesatisfaction subscale (p less than 0.05), physical discomfort andpsychosocial discomfort subscales (p less than 0.05, alvimopan twicedaily only) and the worries and concerns subscale (p less than0.05).(4)

About Opioid Gastrointestinal Side Effects

Opioids, such as morphine, are highly effective in the treatmentof pain and are widely used to treat moderate to severe pain such aspain associated with or as a result of back pain, arthritis and otherpain conditions. However, the use of opioids is associated withpersistent GI side effects such as constipation, characterized byinfrequent, difficult or incomplete bowel movements, abdominal painand discomfort, and bloating.(5) Other GI side effects related toopioids include acid reflux and loss of appetite.

Opioids reduce pain by binding to opioid receptors in the brain.However, there are also opioid receptors in the GI tract. GI sideeffects occur because opioids also bind to mu-opioid receptors in thegut, reducing GI motility and secretions.

Constipation is the most common, persistent and debilitating ofthe GI side effects(6) although its prevalence and impact areseriously under-recognized by healthcare professionals.(7) It isranked by most cancer patients as an even more common source ofdistress than pain, impacting quality of life.(8) Studies have shownthat constipation is experienced by between 50-90% of patients whotake opioids.(2, 9, 10, 11)

GI side effects can be distressing for patients causing asignificant burden of illness and reduced quality of life. Somepatients receiving long-term opioid treatment for pain would ratherendure their pain than the severe, incapacitating constipation thatopioids may cause.(10)

There is currently no approved drug specifically for the treatmentof gastrointestinal side effects associated with opioid use forpersistent pain. Taking stool softeners, bowel stimulants, increasingdaily fluid and fiber intake and increasing exercise are methods oftenused to manage this condition. Laxatives may provide limited relieffor some patients, but can also be associated with side effects suchas abdominal cramping, bloating and unpredictability of effect, andare not recommended for long-term use.

About Alvimopan (Entereg(R))

Alvimopan is an investigational peripherally acting mu-opioidreceptor (PAM-OR) antagonist designed to inhibit the negative effectsof opioids, like morphine or codeine, on the gastrointestinal systemwithout interfering with the analgesic effects on the central nervoussystem. Alvimopan is the first of this new class of compounds with aNew Drug Application (NDA) that has been accepted for review by theU.S. Food and Drug Administration (FDA) for postoperative ileus (POI).

Adolor Corporation and GlaxoSmithKline are collaborating on theworldwide development and commercialization of alvimopan for POI andgastrointestinal side effects associated with the use of opioids totreat persistent pain. As previously announced, GSK is conductingstudies investigating efficacy and safety in non-cancer and cancerpatients taking opioids for treatment of persistent pain.

About GlaxoSmithKline

GlaxoSmithKline is one of the world's leading research-basedpharmaceutical and healthcare companies and is committed to improvingthe quality of human life by enabling people to do more, feel betterand live longer. For more information, visit GlaxoSmithKline on theWorld Wide Web at www.gsk.com.

About Adolor Corporation

Adolor Corporation (NASDAQ:ADLR) is a biopharmaceutical companyspecializing in the discovery, development and commercialization ofnovel prescription pain management products. Entereg(R) (alvimopan) isAdolor's lead product candidate under development for the managementof the gastrointestinal side effects associated with opioid use.Adolor is developing a sterile lidocaine patch which is in Phase 2clinical development for post-surgical incisional pain. Adolor alsohas a number of discovery research programs focused on theidentification of novel compounds for the treatment of pain. Byapplying its knowledge and expertise in pain management, along withingenuity, Adolor is seeking to make a positive difference forpatients, caregivers and the medical community. For more information,visit www.adolor.com.

GlaxoSmithKline Forward-Looking Statements

Under the safe harbor provisions of the US Private SecuritiesLitigation Reform Act of 1995, the company cautions investors that anyforward-looking statements or projections made by the company,including those made in this announcement, are subject to risks anduncertainties that may cause actual results to differ materially fromthose projected. Factors that may affect the Group's operations aredescribed under 'Risk Factors' in the Operating and Financial Reviewand Prospects in the company's Annual Report on Form 20-F for 2005.

Adolor Corporation Forward-Looking Statements

This release, and oral statements made with respect to informationcontained in this release, constitute forward-looking statementswithin the meaning of the Private Securities Litigation Reform Act of1995. Such forward-looking statements include those which expressplan, anticipation, intent, contingency, goals, targets or futuredevelopment and/or otherwise are not statements of historical fact.These statements are based upon management's current expectations andare subject to risks and uncertainties, known and unknown, which couldcause actual results and developments to differ materially from thoseexpressed or implied in such statements. Such known risks anduncertainties relate to, among other factors: the risk that theresults of the alvimopan (Entereg(R)) Phase 3 Studies in opioidinduced gastrointestinal side effects are not positive; the risk thatregulatory approvals for use of alvimopan in patients taking opioidsfor persistent pain are not achieved; the risk that Adolor may notobtain FDA approval for the new drug application for Entereg(R) inpostoperative ileus (POI); the risk that further studies of Entereg(R)are not positive or have adverse safety findings; the costs, delaysand uncertainties inherent in scientific research, drug development,clinical trials and the regulatory approval process; Adolor's historyof operating losses since inception and its need for additional fundsto operate its business; Adolor's reliance on its collaborators,including GlaxoSmithKline in connection with the development andcommercialization of Entereg(R); market acceptance of Adolor'sproducts, if regulatory approval is achieved; competition; andsecurities litigation.

Further information about these and other relevant risks anduncertainties may be found in Adolor's Reports on Form 8-K, 10-Q and10-K filed with the U.S. Securities and Exchange Commission. Adolorurges you to carefully review and consider the disclosures found inits filings, which are available in the SEC EDGAR database athttp://www.sec.gov and from Adolor at http://www.adolor.com. Given theuncertainties affecting pharmaceutical companies in the developmentstage, you are cautioned not to place undue reliance on any suchforward-looking statements, any of which may turn out to be wrong dueto inaccurate assumptions, unknown risks, uncertainties or otherfactors. Adolor undertakes no obligation to (and expressly disclaimsany such obligation to) publicly update or revise the statements madeherein or the risk factors that may relate thereto whether as a resultof new information, future events, or otherwise.
References

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