Bezlotoxumab Treatment Reduced C diff Recurrence in Cancer Patients, Study Reports

Bezlotoxumab can decrease the incidence of recurrent Clostridioides difficile (C diff) infection among patients with cancer, according to a report published in Open Forum Infectious Diseases.

A multinational team of investigators conducted an exploratory post-hoc analysis of patients, with and without cancer, in order to determine how bezlotoxumab affected the rate of C diff-related outcomes.

Incidence of C diff is reportedly higher in cancer patients and the cure rates are lower, according to the authors. Bezlotoxumab has been approved in the United States and Europe to prevent recurrent C diff in adult patients who are receiving anti-C diff infection antibiotics and who are at a high risk of C diff infection.

As patients with cancer may be immunocompromised, their treatment may include antimicrobial therapy, which can further increase the risk for C diff infection and recurrent infections, the study authors wrote.

Patients in the MODIFY I and II studies—from which the patients were screened for this analysis—received a single 10 mg/kg infusion of bezlotoxumab either alone or in combination with actoxumab. Both treatments reduced recurrent C diff infections over 12 weeks compared to placebo. Because the patients were screened from a phase 3 trial, the results may not be fully representative of a real-world problem, the study authors noted.

From this group, the investigators identified 382 patients who were diagnosed with cancer, or about 25%. There were 190 patients from the bezlotoxumab group and 192 from the placebo cohort. The study authors also noted that of the participants without cancer, 591 and 581 received bezlotoxumab and placebo, respectively.

For the group that received placebo treatment, C diff recurrence was similar among cancer and non-cancer patients at 30% and 34%, respectively. Additionally, those with cancer achieved fewer instances of initial clinical cure than participants without cancer at 72% vs. 83%, respectively, the investigators said.

Among the patients with cancer, receiving the bezlotoxumab treatment had no effect on initial clinical cure rate compared to the placebo treatment, they added, reaching 76% vs. 71%, respectively. However, bezlotoxumab resulted in a statistically significant reduction in recurrent C diff infection versus placebo among the patients with cancer.

“The difference between the bezlotoxumab and placebo groups for the primary endpoint, C diff infection recurrence, and many of the additional endpoints we studied in this post-hoc analysis were similar in cancer patients and non-cancer patients,” said study author Mary Beth Dorr, PhD, Clinical Director Infectious Diseases at Merck & Co. “However, there was one notable difference that was unexpected.”

As Dorr hinted, the study authors discovered a trend for lower mortality rate at 90-days in bezlotoxumab-treated cancer patients compared to those who received placebo: 10.5% vs. 14.5%, respectively.

“While this result is encouraging, this trend was not statistically significant and further study would be needed to confirm this observation,” she continued.

The investigators also wrote that the rate of C diff infection-associated 30-day rehospitalization was lower in cancer patients who received bezlotoxumab compared to those who were treated with placebo.

“Cancer patients that experience an episode of C diff infection are often immunosuppressed and a recurrence could negatively impact their outcomes or delay chemotherapy treatments,” Dorr continued. “Bezlotoxumab is an option to decrease the incidence of C diff infection recurrence in this fragile patient population.”