From the AGA Journals

Two-thirds with microscopic colitis respond to bile acid sequestrants

Publish date: October 11, 2023
By
Will Pass
MDedge News

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Despite being increasingly recognized and diagnosed, there remains a scantiness of studies addressing therapeutic options in microscopic colitis (MC). Oral budesonide is recommended as first-line option; however, there is a high relapse rate after budesonide discontinuation, some patients are intolerant, and there is concern for steroid toxicity associated with long-term exposure.

While the cause of MC remains elusive, there is a rationale to suggest that bile acids may play a role in disease pathogenesis. Not only are BA important signaling molecules, acting in inflammation and metabolism, but also prior small studies reported on BA malabsorption co-existing in MC, with variable response rates to BA sequestrants.

This retrospective large study of 282 patients with MC showed that almost two-thirds of patients will present a complete or partial response to BA sequestrant therapy (cholestyramine, colesevelam, and colestipol). For those that relapsed following BA therapy discontinuation, re-treatment was successful in the majority of cases.

Therapy was well tolerated, however caution is needed, as it can interfere with absorption of other medications, and in the long-term also with fat-soluble vitamins. It remains to be determined which patients could benefit the most from BA therapy, since no predictors of response were identified, nor was response associated with BA malabsorption. Nonetheless, this study shows that BA therapy could be an attractive option for steroid-dependent, steroid refractory or intolerant MC patients potentially worth trying before embarking on immunosuppressive or biological therapy. It also highlights the need for carefully conducted clinical trials exploring other options beyond budesonide for this chronic and debilitating condition.

Joana Torres, MD, PhD, is a consultant gastroenterologist at Hospital Beatriz Angelo and Hospital da Luz in Portugal and assistant professor in Uniersidade de Lisboa, Portugal. She has no conflicts.


 

FROM CLINICAL GASTROENTEROLOGY AND HEPATOLOGY

Approximately two out of three patients with microscopic colitis respond to bile acid sequestrants (BAS), and therapy is generally well tolerated, based on a recent retrospective study from the Mayo Clinic.

The findings support use of BAS in patients with microscopic colitis who fail first-line therapy, or have intolerance to those agents, wrote researchers who were led by Darrell S. Pardi, MD, AGAF, a gastroenterologist with Mayo Clinic, Rochester, Minn. To date, the American Gastroenterological Association (AGA) has refrained from issuing any recommendations for BAS monotherapy in microscopic colitis (MC), the study authors wrote, citing a lack of relevant data.

The AGA recommends budesonide as first-line therapy for patients with moderate to severe symptoms of microscopic colitis. However, the treatment is associated with a high rate of relapse (40%-81%) once the patient stops taking the drug. Its long-term use is associated with a risk of side effects.

“At present, there are no randomized controlled trials that have evaluated the efficacy of BAS monotherapy for MC,” the investigators wrote in Clinical Gastroenterology and Hepatology. “Studies investigating the role of BAM [bile acid malabsorption] in MC are comprised of small cohorts and have shown inconsistent results. Patients without BAM may also respond to BAS therapy. Therefore, the role of BAM and treatment with BAS in MC merits further investigation.”

The study analyzed data from 282 patients (88.3% women) with microscopic colitis treated between 2010 to 2020. Bile acid malabsorption was defined by elevated serum 7⍺-hydroxy-4-cholesten-3-one or by fecal testing. After a median follow-up of 4.5 years, cholestyramine was the most prescribed BAS (64.9%), followed by colesevelam (21.6%) and colestipol (13.5%). Approximately half of the patients achieved a complete response (49.3%), while 16.3% had a partial response. Nonresponders accounted for 24.8% of the population, and 9.6% of patients did not tolerate BAS therapy. These outcomes were not significantly impacted by BAS dose or combination with other agents. Additional logistic regression analysis revealed no predictors of response.

After discontinuing BAS, 41.6% of patients had recurrence in a median of 21 weeks, ranging from 1 to 172 weeks.

“Consistent with prior studies evaluating the clinical course of MC and similar to the high rate of recurrence after discontinuation of budesonide, relapse was common after cessation of BAS therapy,” the investigators noted.

Still, the findings suggest that BAS is a valid second-line option with a favorable risk-benefit profile, and an elevated dose appears unnecessary to achieve clinical response.

“These results suggest that BAS may be considered as a treatment option in those that do not respond to first-line options or have intolerance to these agents,” the researchers wrote.

They suggested that BAS may be particularly useful as long-term maintenance therapy for patients wishing to avoid prolonged corticosteroid exposure.

“However, BAS have the potential to interfere with the administration and absorption of other medications, particularly in older populations with polypharmacy,” the researchers wrote. “Patients should thus be closely monitored for drug interactions, especially those taking concurrent medications. BAS should be administered separately from other medications to avoid the potential for drug interactions.”

Ideally, prospective studies will be conducted to confirm these findings, and to identify the subset of patients who are most likely to respond to BAS, the investigators concluded.

Dr. Pardi has grant funding from Pfizer, Vedanta, Seres, Finch, Applied Molecular Transport, and Takeda; and has consulted for Vedanta, Seres, Phantom Pharmaceuticals, Abbvie, Immunic, and Otsuka.

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