From the Guidelines
The recommended treatment for this 56-year-old man with small cell lung cancer (SCLC) on pembrolizumab who has developed diarrhea (4-5 stools per day despite loperamide) is prednisone, starting with an initial dose of 1 mg/kg/day, as per the guidelines outlined in the Journal of Clinical Oncology 1.
Key Considerations
- The patient's symptoms are consistent with grade 2 immune-related colitis, which requires immediate attention and treatment with corticosteroids.
- The use of loperamide has not been effective in managing the patient's symptoms, and therefore, prednisone is the next line of treatment.
- Infliximab would be considered only if symptoms persist after 3-5 days of corticosteroid therapy, making it a second-line option, as suggested by the ASCO guideline update 1.
- Cyclophosphamide is not typically used for immune-related colitis and would be inappropriate in this clinical scenario.
Treatment Approach
- The patient should be started on prednisone 1 mg/kg/day, with a gradual taper over 4-6 weeks once symptoms improve, as recommended by the Journal of Clinical Oncology 1.
- The pembrolizumab should be temporarily withheld during treatment of moderate immune-related colitis, as suggested by the Society for Immunotherapy of Cancer (SITC) toxicity management working group 1.
- The patient should be closely monitored for any signs of improvement or worsening of symptoms, and the treatment plan should be adjusted accordingly.
Additional Recommendations
- Consider consult with gastroenterology for grade 2 immune-related colitis, as recommended by the Journal of Clinical Oncology 1.
- Endoscopic evaluation with EGD or colonoscopy is highly recommended for cases grade 2 to stratify patients for early treatment of biologics based on the endoscopic findings, as suggested by the ASCO guideline update 1.
From the Research
Treatment Options for Diarrhea in SCLC Patient Under Pembrolizumab
- The patient has developed diarrhea (4-5 stools per day) despite loperamide, and options include prednisone, infliximab, or cyclophosphamide.
- According to 2, prednisone can be effective in treating gastrointestinal symptoms, but the study focused on acute graft-versus-host disease, not diarrhea induced by pembrolizumab.
- 3 discusses the use of prednisone, cyclophosphamide, and other medications in a metronomic chemotherapy regimen for recurring/refractory lymphoma, but does not specifically address diarrhea treatment.
- Infliximab, a TNF inhibitor, has been used to treat refractory polyarteritis nodosa 4 and may be considered for treating diarrhea, but its effectiveness in this context is unclear.
- 5 notes that prednisone, infliximab, and cyclophosphamide may be associated with an increased risk of interstitial lung disease, but does not provide direct evidence for their use in treating diarrhea.
- 6 describes a combination therapy including cyclophosphamide and prednisone for primary membranous nephropathy, but its relevance to treating diarrhea in SCLC patients under pembrolizumab is limited.
Considerations for Each Option
- Prednisone: may be effective in treating gastrointestinal symptoms, but its use in diarrhea induced by pembrolizumab is not well established 2.
- Infliximab: has been used to treat refractory polyarteritis nodosa 4, but its effectiveness in treating diarrhea is unclear.
- Cyclophosphamide: has been used in combination with prednisone for various conditions 3, 6, but its role in treating diarrhea is not well defined.