WASHINGTON – , according to Yinghong Wang, MD.
In two patients who developed severe, refractory, immune-mediated colitis (IMC), FMT led to recovery, Dr. Wang of M.D. Anderson Cancer Center, Houston, reported at the annual meeting of the Society for Immunotherapy of Cancer.
Patient 1 was a woman with renal cell cancer who developed grade 2+ IMC within 1 month of initiation of treatment with combined ipilimumab and nivolumab. Infectious etiology was ruled out, and her symptoms and ulcers persisted despite 3 months of treatment with corticosteroids, two doses of infliximab, and one dose of vedolizumab.
A single FMT delivered via colonoscopy led to complete symptom resolution within 10 days, and a repeat colonoscopy showed “very nice healing of inflammation and ulcers,” Dr. Wang said.
Patient 2 was a man with prostate cancer who developed grade 2+ IMC 3 months after receiving two doses of ipilimumab. Infectious etiologies were ruled out, and like patient 1, his symptoms and mucosal ulcerations persisted despite 5 months of immunosuppression with corticosteroids, two doses of infliximab, and three doses of vedolizumab. He underwent two FMTs via colonoscopy.
“The first fecal transplant achieved partial response, and the second fecal transplant achieved complete clinical response, and this remission was sustained for a total of 8 months,” Dr. Wang said.
Immune checkpoint inhibitor–related IMC is typically treated with immunosuppressive therapy that is associated with significant morbidity, including a possible adverse impact on the antitumor effects of checkpoint inhibitors, Dr. Wang said.
However, studies have suggested that “the microbiome in healthy people potentially plays a very important and synergistic role for tumor regression in combination with immunotherapy,” and animal models also suggest that patients who develop IMC have differential bacterial signatures in their gut microbiome, she said.
“Based on that preliminary information, we performed fecal transplant as a compassionate treatment for cases refractory to all immunosuppression in June 2017 at M.D. Anderson,” she said.
Stool microbiome analyses showed successful engraftment of donor microbiome in recipient stool samples, and microbiome taxonomy showed increases in specific Escherichia species that “we think potentially play a role in this colitis recovery,” she said.
“Fecal transplant is safe and effective based on our preliminary study,” she said, adding that restoration of a healthy microbiome seems to reverse IMC. “Future large-scale studies are needed to evaluate this finding.”
Dr. Wang reported having no disclosures.
SOURCE: Wang Y et al. SITC 2018, Abstract P194.