Presence of constipation predicts the therapeutic efficacy of pembrolizumab in metastatic urothelial cancer patients

OBJECTIVES

To study bowel function in urothelial cancer patients treated with pembrolizumab and to assess its association with treatment efficacy.

METHODS

This retrospective study was analyzed for patients with metastatic urothelial cancer who received immune checkpoint inhibitor treatment between December 2017 and June 2019 at Nagoya University and affiliated hospitals in Japan. The association between bowel dysfunction (defined as constipation or need for laxatives) and treatment efficacy was investigated.

RESULTS

We retrospectively enrolled 73 patients with metastatic urothelial cancer who received immune checkpoint inhibitor treatment. All patients received pembrolizumab at 200 mg per bodyweight administered intravenously every 3 weeks. Performance status was 0-1 in 58 patients (79.5%), and liver metastasis was detected in 22 patients (30.1%). The median age was 72 years (range 40-89 years). A total of 45 patients had constipation. The median progression-free survival and overall survival from the start of immune checkpoint inhibitor treatment was 4.0 months (95% confidence interval 1.0-17.3) and 6.6 months (95% confidence interval 1.0-18.0), respectively. Patients with constipation had a significantly higher risk of disease progression (P = 0.005). There was no significant association between constipation and overall survival (P = 0.131). However, complete response was observed among two patients treated with immune checkpoint inhibitor, both of whom did not present constipation.

CONCLUSION

The presence of constipation might be a prognostic factor for urothelial cancer patients undergoing immune checkpoint inhibitor treatment.

Impact of bowel movement condition on immune checkpoint inhibitor efficacy in patients with advanced non-small cell lung cancer

Background

Cancer immunotherapy is under development as a promising alternative strategy for treating advanced non‐small cell lung cancer (NSCLC). However, the development of novel biomarkers to optimize the use of immune checkpoint inhibitors (ICIs) is still ongoing. Gut microbiota are known to regulate a host's immunity and are associated with the response to ICIs in melanoma. Therefore, we analyzed the association between ICI treatment efficacy and bowel movement condition in patients with NSCLC.

Methods

This retrospective study analyzed patients with advanced NSCLC who were treated with ICIs between December 2015 and March 2018 at University Hospital Kyoto Prefectural University of Medicine in Kyoto, Japan. The association between stool abnormalities and ICI efficacy was investigated. We defined patients with constipation or those who used a laxative as the stool abnormality group.

Results

We retrospectively enrolled 40 patients with advanced NSCLC who were treated with ICIs. The median age was 69.5 years; 20 patients had a stool abnormality and 20 patients did not. The disease control rates were lower in NSCLC patients with stool abnormalities than in those without stool abnormalities (20% vs. 77.8%, respectively; P = 0.0016). The time to treatment failure with ICI treatment was shorter in NSCLC patients with stool abnormalities compared with those without stool abnormalities (P = 0.003; odds ratio, 3.09; 95% confidence interval 1.41–6.78).

Conclusion

Stool abnormality might be a predictive biomarker for the clinical benefit of ICI treatment in patients with NSCLC. Further investigations are warranted to validate our findings.