Salix Presents New Rifaximin Phase IIB Data Demonstrating Significant and Sustained Improvement in Diarrhea–Associated Irritable Bowel Syndrome (d–IBS)
Results Presented at Digestive Disease Week 2008 Further Support Potential of
Non–absorbed, Gut–selective Antibiotic as Novel Treatment for IBS Symptoms
SAN DIEGO, CA, May 20, 2008 – Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) today announced
findings from two analyses of the Phase IIb clinical
trial of rifaximin, its non–absorbed, gut–selective antibiotic for the treatment of patients with diarrhea–associated irritable
bowel syndrome (d–IBS). Data presented at Digestive Disease Week 2008 showed that patients treated with rifaximin demonstrated statistically
greater clinical improvement in both co–primary endpoints of adequate relief of global IBS symptoms (SGA) and of adequate relief of bloating
(BL) compared to placebo, and the safety profiles were similar between rifaximin and placebo. Improvements were sustained for 12 weeks of follow–up
despite cessation of therapy after 14 days. Data from a supplemental analysis found that the most significant predictors of clinical response
were daily bloating and abdominal pain.
Rifaximin, which Salix markets in the United States under the trade name XIFAXAN® (rifaximin), currently is approved for the treatment of
patients, 12 years of age or older, with travelers' diarrhea caused by non–invasive strains of Escherichia coli.
"These findings provide additional support for the potential sustained benefit of rifaximin – a non–absorbed and gut–selective antibiotic
– as a novel short–term treatment with a long–term response," said Anthony Lembo, MD, Director of the GI Motility Center at the
Beth Israel Deaconess Medical Center in Boston, MA. "Rifaximin appears to prevent the return of d–IBS symptoms to baseline after treatment
is normally stopped."
Dr. Lembo presented data from a Phase IIb multi–center, double–blind, placebo–controlled, randomized trial (Abstract #T1390) that evaluated
the short–term and sustained effectiveness of rifaximin in relieving symptoms of d–IBS compared to placebo as diagnosed by Rome II
criteria. The primary comparison consisted of two groups of adult patients with d–IBS that received rifaximin 550 mg twice daily or placebo
for 14 days, followed by an additional 14 days of placebo in both groups and a 12–week follow–up phase. The results demonstrate that the patients who received rifaximin had significant improvement compared to placebo in both co–primary endpoints of adequate relief of SGA (52% vs. 44% respectively, P=0.03) and adequate relief of BL (46% vs. 40%, P=0.04), with sustained response up to 12 weeks after treatment was discontinued.
Rifaximin was well tolerated, with a safety profile similar to placebo.
"We consider this study – in which rifaximin reached statistical significance in not one, but two, primary endpoints – adequate relief of d–IBS
symptoms and bloating – to be the most demanding assessment of the antibiotic treatment of d–IBS to date," said Bill Forbes, Pharm.D, Vice President, Research and Development, Salix. "These results provide additional support on which to base our pursuit of FDA market clearance
for rifaximin as a new treatment for non–constipating irritable bowel syndrome."
Rifaximin also improved both SGA and BL in equal to or greater than four weeks (p<0.05), during all four weeks (p=0.02), and at week three (p<0.02) and
week four (p<0.02). At week four (end of treatment phase) rifaximin patients achieved relief of SGA (53%) and BL (50%) versus placebo patients (43%)
and (42%), respectively; p=0.01. The beneficial effects of rifaximin compared to placebo were maintained during the 12–week follow–up
period. At the end of the 12–week follow–up, rifaximin treatment resulted in an improvement in SGA versus placebo (62% versus 49%, respectively;
p<0.05) and BL (59% versus 51%, respectively; p<0.05).
Yehuda Ringel, MD, Assistant Professor of Medicine at the University of North Carolina at Chapel Hill School of Medicine and Coordinator of the Center for Functional GI & Motility Disorders, in Chapel Hill, NC presented data (Abstract #T1406) from a supplemental analysis of the Phase IIb study (Abstract
#T1390) that evaluated the potential predictors of clinical response in patients with d–IBS. Rifaximin treatment demonstrated significant
improvement in SGA compared to placebo (52% versus 44%, respectively; p=0.03) and in BL compared to placebo (46% versus 40%, respectively; p=0.04).
The most noted confounders of clinical response were daily bloating, abdominal pain and use of rescue medications.
Adjusting for rescue medication use, the subgroup of patients with mild–to–moderate abdominal pain demonstrated greater improvement with rifaximin
versus placebo for SGA (50% versus 39%; respectively; p=0.04) and for BL (44% versus 35%; respectively; p=0.09). A similar analysis for daily
bloating demonstrated rifaximin achieved a significant clinical response versus placebo for SGA (56% versus 41%, respectively; p=0.006) and BL (47%
versus 36%; respectively; p=0.03). Patient demographics, including age, sex, IBS duration, IBS subtype (d–IBS and a–IBS), diabetes history, screening colonoscopy, as well as use of rescue medications, need for screening colonoscopy and baseline IBS symptoms were evaluated as potential
confounders of response.
About IBS
Among one of the most common chronic conditions, irritable bowel syndrome (IBS) affects approximately 14% of adults in the United States. IBS includes
altered bowel habits with abdominal pain and discomfort. Among other contributors, recent science has shown that alterations in gut flora / bacteria
have been identified as a potentially important contributor to the pathophysiology of IBS. Small intestinal bacterial overgrowth, a condition associated
with excessive numbers of bacteria in the small intestine, may underlie some of the gastrointestinal symptoms associated with IBS.
About XIFAXAN
XIFAXAN® (rifaximin) is a gut–selective antibiotic with negligible systemic absorption (<0.4%) and broad–spectrum activity in
vitro against both gram–positive and gram–negative pathogens. Rifaximin has a similar tolerability profile to that of placebo and has
activity against the most common TD pathogens.
XIFAXAN is under investigation in the United States as a treatment for irritable bowel syndrome. In the United States, the FDA granted marketing clearance
for XIFAXAN tablets 200 mg indicated for the treatment of patients (≥12 years of age) with travelers' diarrhea caused by noninvasive strains of
Escherichia coli. XIFAXAN should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea due to pathogens other than Escherichia coli. XIFAXAN should be discontinued if diarrhea symptoms get worse or persist more than 24–48 hours and alternative antibiotic therapy should be considered. In clinical trials, XIFAXAN was generally well tolerated. The most common side
effects (vs. placebo) were flatulence 11.3% (versus 19.7%), headache 9.7% (versus 9.2%), abdominal pain 7.2% (versus 10.1 %) and rectal tenesmus
7.2% (versus 8.8%).
Rifaximin has been used in Italy for 23 years and is approved in 23 countries. Salix acquired rights to market rifaximin in North America from Alfa Wassermann
S.p.A. in Bologna, Italy. Alfa Wassermann markets rifaximin in Italy under the trade name Normix®.
About Salix
Salix Pharmaceuticals, Ltd., headquartered in Raleigh, North Carolina, develops and markets prescription pharmaceutical products for the treatment of gastrointestinal
diseases. Salix's strategy is to in–license late–stage or marketed proprietary therapeutic drugs, complete any required
development and regulatory submission of these products, and market them through the Company's 150–member gastroenterology specialty sales and
marketing team.
Salix also markets COLAZAL® (balsalazide disodium) Capsules 750 mg, OSMOPREP® (sodium phosphate monobasic monohydrate, USP
and sodium phosphate dibasic anhydrous, USP) Tablets, MOVIPREP® (PEG 3350, Sodium Sulfate, Sodium Chloride, Potassium Chloride, Sodium
Ascorbate and Ascorbic Acid for Oral Solution), VISICOL® (sodium phosphate monobasic monohydrate, USP, and sodium phosphate dibasic
anhydrous, USP) Tablets PEPCID® (famotidine) for Oral Suspension, Oral Suspension DIURIL® (Chlorothiazide), AZASAN®
(azathioprine Tablets, USP, 75/100 mg) , ANUSOL–HC® 2.5% (Hydrocortisone Cream, USP), ANUSOL–HC®
25 mg Suppository (Hydrocortisone Acetate), PROCTOCORT® Cream (Hydrocortisone Cream, USP) 1% and PROCTOCORT® Suppository
(Hydrocortisone Acetate Rectal Suppositories) 30 mg. Balsalazide tablet, encapsulated mesalamine granules, vapreotide acetate, metoclopramide–Zydis® and (XIFAXAN®) rifaximin for additional indications are under development.
For full prescribing information on Salix products, please visit www.salix.com or
contact the Company at 919–862–1000.
Salix trades on the NASDAQ Global Select Market under the ticker symbol "SLXP".
For more information please visit our web site at www.salix.com or contact the Company at 919–862–1000. Information on our web site is not incorporated
in our SEC filings.
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APRISO™ is a locally-acting aminosalicylate indicated for the maintenance of remission of ulcerative colitis in patients 18 years and older.
APRISO is contraindicated in patients with hypersensitivity to salicylates, aminosalicylates, or to any of the components of APRISO capsules.
The recommended dose of APRISO is four 0.375 g capsules once daily in the morning (1.5 g/day) with or without food. Because dissolution of the coating of APRISO
granules depends on pH, APRISO should not be coadministered with antacids. Patients with phenylketonuria should be aware that APRISO contains aspartame,
equivalent to 0.56 mg of phenylalanine. In two well-controlled clinical trials, the most common treatment-related adverse events occurring in at least 3%
of adult patients taking 1.5 g/day of APRISO were headache (11% vs. 8% for placebo), diarrhea (8% vs. 7% for placebo), upper abdominal pain (5% vs 3% for placebo),
nausea (4% vs 3% for placebo), nasopharyngitis (4% vs 3% for placebo), influenza and influenza-like illness (4% vs 4% for placebo) and sinusitis (3% vs 3% for placebo).
For complete Prescribing Information, please click here.
MOVIPREP® (PEG-3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate and ascorbic acid for oral solution) is indicated for cleansing of the
colon as a preparation for colonoscopy in adults 18 years of age or older. MOVIPREP is contraindicated in patients who have had a severe hypersensitivity reaction
to any of its components. MOVIPREP should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities, in patients with known or suspected hyponatremia,
severe ulcerative colitis, ileus, gastrointestinal obstruction or perforation, gastric retention, toxic colitis, toxic megacolon, or glucose-6-phosphate dehydrogenase deficiency. In clinical trials, abdominal
distention, anal discomfort, thirst, nausea, and abdominal pain were the most common adverse reactions to MOVIPREP administration. MOVIPREP contains a maximum of 2.33 mg of phenylalanine per treatment.
Consult with your physician to see if this product is right for you.
For complete Prescribing Information, please click here.
Important Safety Information about OSMOPREP
There have been rare, but serious reports of acute phosphate nephropathy in patients who received oral sodium phosphate products for colon cleansing prior
to colonoscopy. Some cases have resulted in permanent impairment of renal function and some patients required long–term dialysis. While some
cases have occurred in patients without identifiable risk factors, patients at increased risk of acute phosphate nephropathy may include those with
increased age, hypovolemia, increased bowel transit time (such as bowel obstruction), active colitis, or baseline kidney disease, and those using
medicines that affect renal perfusion or function (such as diuretics, angiotensin converting enzyme [ACE] inhibitors, angiotensin receptor blockers
[ARBs], and possibly nonsteroidal anti–inflammatory drugs [NSAIDs]).
It is important to use the dose and dosing regimen as recommended (PM/AM split dose).
OSMOPREP® (sodium phosphate monobasic monohydrate, USP, and sodium phosphate dibasic anhydrous, USP) Tablets are indicated for cleansing
of the colon as a preparation for colonoscopy in adults 18 years of age or older. Considerable caution should be advised before OSMOPREP is used in
patients with severe renal insufficiency, congestive heart failure, ascites, unstable angina, gastric retention, ileus, severe chronic constipation,
bowel perforation, toxic megacolon, gastric bypass or stapling surgery, or hypomotility syndrome. Use with caution in patients with impaired renal
function, patients with a history of seizures or at higher risk of seizure, patients with higher risk of cardiac arrhythmias, known or suspected electrolyte
disturbances (such as dehydration), or people taking drugs that affect electrolyte levels. Patients with electrolyte abnormalities such as
hypernatremia, hyperphosphatemia, hypokalemia, or hypocalcemia should have their electrolytes corrected before treatment with OSMOPREP.
OSMOPREP is contraindicated in patients with a known allergy or hypersensitivity to sodium phosphate salts or any of its ingredients, and in patients with
biopsy–proven acute phosphate nephropathy. In clinical trials, the most commonly reported adverse reactions (reporting frequency >3%) were
abdominal bloating, nausea, abdominal pain, and vomiting. It is recommended that patients receiving OSMOPREP be advised to adequately hydrate before,
during, and after the use of OsmoPrep.
For complete Prescribing Information for OSMOPREP including BOXED WARNING, please click here.
Important Safety Information about XIFAXAN 550 mg
XIFAXAN® 550 mg is indicated for reduction in risk of overt hepatic encephalopathy (HE) recurrence in patients ≥18 years of age. In the trials of XIFAXAN for HE, 91% of the patients were using lactulose concomitantly. XIFAXAN has not been studied in patients with MELD scores >25, and only 8.6% of patients in the controlled trial had MELD scores over 19. There is increased systemic exposure in patients with more severe hepatic dysfunction. Therefore, caution should be exercised when administering XIFAXAN to patients with severe hepatic impairment (Child-Pugh C).
XIFAXAN is contraindicated in patients with a hypersensitivity to rifaximin, any of the rifamycin antimicrobial agents, or any of the components in XIFAXAN. Hypersensitivity reactions have included exfoliative dermatitis, angioneurotic edema, and anaphylaxis.
Clostridium difficile–associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including XIFAXAN, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon which may lead to overgrowth of C difficile. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C difficile may need to be discontinued.
The most common adverse reactions occurring in >8% of patients in the clinical study were edema peripheral (15%), nausea (14%), dizziness (13%), fatigue (12%), ascites (11%), muscle spasms (9%), pruritus (9%), and abdominal pain (9%).
For complete Prescribing Information, please click here.
Important Safety Information about METOZOLV ODT
Treatment with metoclopramide can cause tardive dyskinesia, a serious movement disorder that is often irreversible.
The risk of developing tardive dyskinesia increases with the duration of treatment and the total cumulative dose.
Metoclopramide therapy should be discontinued in patients who develop signs or symptoms of tardive dyskinesia.
There is no known treatment for tardive dyskinesia. In some patients, symptoms may lessen or resolve after metoclopramide treatment is stopped.
Treatment with metoclopramide for longer than 12 weeks should be avoided in all but rare cases where therapeutic benefit is thought to outweigh the risk of developing tardive dyskinesia.
METOZOLV® ODT
(metoclopramide HCl) is indicated as short-term (4 to 12 weeks) therapy for adults with symptomatic, documented gastroesophageal
reflux disease (GERD) who fail to respond to conventional therapy and for the relief of symptoms associated with acute and
recurrent diabetic gastroparesis (diabetic gastric stasis) in adults. Therapy should not exceed 12 weeks in duration. Take on
an empty stomach up to four times daily, at least 30 minutes before eating and at bedtime.
METOZOLV ODT is contraindicated in patients with intestinal obstruction, hemorrhage, or perforation; pheochromocytoma;
known sensitivity or intolerance to metoclopramide; epilepsy; or are receiving concomitant medications with extrapyramidal reactions.
Extrapyramidal symptoms (EPS), manifested primarily as acute dystonic reactions, occur in approximately 1 in 500 patients treated with the
usual adult dosages of 30 to 40 mg/day of metoclopramide. These usually are seen during the first 24 to 48 hours of treatment with metoclopramide,
occur more frequently in pediatric patients and adult patients less than 30 years of age and are even more frequent at higher doses.
Drug-induced Parkinsonism can occur during metoclopramide therapy, more commonly within the first 6 months after beginning treatment,
but also after longer periods. Patients with a history of Parkinson’s disease should be given metoclopramide cautiously, if at all,
since such patients can experience exacerbation of Parkinsonian symptoms when taking metoclopramide.
There have been rare reports of an uncommon but potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) associated
with metoclopramide. Clinical manifestations of NMS include hyperthermia, muscle rigidity, altered consciousness, and evidence of autonomic instability.
The management of NMS should include immediate discontinuation of metoclopramide and other drugs not essential to concurrent therapy.
Depression associated with metoclopramide use has occurred in patients with and without a history of depression.
For those patients with a prior history of depression, metoclopramide should only be given if the expected benefits outweigh the potential risks.
In one study in hypertensive patients, intravenously administered metoclopramide was shown to release catecholamines; hence, caution should be exercised
when metoclopramide is used in patients with hypertension. Any rapid rise in blood pressure associated with METOZOLV ODT use should result in immediate
cessation of metoclopramide use in those patients.
Since metoclopramide produces a transient increase in plasma aldosterone, patients with cirrhosis or congestive heart failure may be at risk of developing
fluid retention and volume overload. If these side effects occur at any time in any patients during metoclopramide therapy, the drug should be discontinued.
Adverse reactions, especially those involving the nervous system, may occur after stopping the use of METOZOLV ODT.
In clinical studies, the most frequently reported adverse events (≥2% occurrence) were headache, nausea, fatigue, somnolence, and vomiting.
Full Prescribing Information for METOZOLV ODT, including BOXED WARNING.