New Approaches to IBS and IBD, But Concerns About PPIs, Highlighted at DDW
A new test to identify diarrhea-predominant irritable bowel syndrome (D-IBS) and a new class of drugs to treat ulcerative colitis were presented at Digestive Disease Week (DDW) in Washington DC, May 15–19. Researchers also warned that many residents of nursing homes are being inappropriately given proton pump inhibitors (PPIs).
Mark Pimentel (Cedars-Sinai Medical Center, Los Angeles) described development of a test that might allow patients with D-IBS to avoid invasive endoscopies to check for Crohn’s disease or ulcerative colitis.
MedPage Today reported his findings from a study of 2375 patients with D-IBS (according to Rome III criteria), 142 with IBD, 121 with celiac disease, and 43 healthy volunteers (controls).
According to the Washington Post, the test detects antibodies to cytolethal distending toxin B (CdtB) and vinculin, which are released by bacteria that cause food poisoning.
Medpage Today wrote that at cutoffs optimized for specificity, the combined results from anti-CdtB and anti-viculin tests identified patients with IBS-D with over 90% specificity a positive predictive value of 98.6%. The findings were recently published online in PLOS ONE.
US News explained that since there’s no conclusive way to identify IBS, doctors typically perform complex and invasive procedures, such as colonoscopy, to rule out other diseases. The antibody tests could therefore make diagnosis of IBS less complex.
However, the tests could not accurately distinguish IBS from celiac disease (area under the curve values of about 0.6 and specificity values in the range of 80%). Pimentel told MedPage Today that this was not a problem because tests for celiac disease are less burdensome for patients.
Pratik Rane (University of Houston; abstract 497) reported that almost half of elderly residents in nursing homes who are prescribed PPIs are receiving them without an evidence-based indication. He reported findings from a retrospective cross-sectional study that examined data from the National Nursing Home Survey.
Medscape Medical News wrote that of 1.5 million nursing home residents, 355,600 received at least 1 PPI—most commonly for chronic cough—for which evidence of efficacy is lacking.
PPIs are used to treat disorders such as ulcers and acid reflux disease, and are generally considered to be safe. However, risks associated with their use include pneumonia, fractures, and Clostridium difficile infections, which already occur in a high proportion of nursing home residents.
“Among the elderly recipients of PPIs, 44.72% were prescribed the drugs without an appropriate indication,” said Rane.
In the multivariable logistic regression analysis, chronic cough was associated with the highest adjusted odds ratio (OR) for inappropriate use (OR, 2.62). Patients were less likely to receive the drugs inappropriately if they had osteoporosis (OR, 0.59), which Rane said was reassuring.
“Physicians were cautious in prescribing PPIs without an indication for patients with osteoporosis in the current study,” he said.
PPIs were also less likely to be prescribed to patients receiving a selective serotonin reuptake inhibitor (OR, 0.83)—a group that is at increased risk for upper gastroesophageal reflux disease.
John Inadomi (University of Washington) told Medscape Medical news that it’s time to find ways to do something about inappropriate use of PPIs. He explained that that some PPI prescriptions might be part of order sets—if PPIs are taken off the list of inpatient order sets, physicians would have to think about prescribing them.
William Sandborn (University of California, San Diego; abstract 445) reported findings from a phase 2 trial showing that ozanimod, a sphingosine 1-phosphate (SP1) receptor modulator, is safe and effective in the treatment of patients with moderate to severe ulcerative colitis.
Medscape Medical News wrote that an international 8-week induction trial involved 197 patients with moderate to severe ulcerative colitis (Mayo scores of 6–12 and endoscopy subscores ≥2).
According to PM360, 197 adults were randomly assigned to groups given 0.5 mg or 1.0 mg ozanimod or placebo. Doses were titrated through week 1, followed by 8 weeks of full-dose therapy. The primary end point was clinical remission at week 8 (Mayo score of ≤2 and no subscore > 1).
Sandborn said that 1 mg ozanimod induced clinical remission at week 8 and met all 3 of the secondary end points.
Patients receiving 1.0 mg ozanimod had significant improvements in clinical response, remission, mucosal improvement, and Mayo scores, compared with patients given placebo.
The difference between 0.5 mg ozanimod and placebo was significant for mucosal improvement.
Adverse event profiles were comparable among the groups; approximately 31% of patients had an adverse event in each group. Three patients receiving ozanimod had transient increases in level of alanine aminotransferase.
SP1 receptor modulators sequester lymphocytes and prevent their migration to areas of inflammation. These agents are also in phase 3 trials for patients with multiple sclerosis.
“This is a new class of drug that might work differently from current drugs for inflammatory bowel disease,” said Charles Bernstein (University of Manitoba) told Medscape Medical News
The induction portion of the study was completed by 95% of patients, and responders will continue into a maintenance period. A phase 3 trial is being planned, along with a phase 2 study in patients with Crohn’s disease.