Immune checkpoint inhibitor–related mucositis (pembrolizumab)
Pembrolizumab-associated mucositis should be managed as an immune-mediated adverse event using CTCAE grade to guide interruption of pembrolizumab and initiation and taper of systemic corticosteroids. [1] Systemic corticosteroids are indicated for grade 3 immune-mediated adverse reactions and are stopped or tapered only after clinical improvement to grade 1 or less, with taper over at least 1 month for KEYTRUDA-associated immune-mediated toxicity requiring systemic steroids. [1] Permanent discontinuation of pembrolizumab is recommended for life-threatening (grade 4) immune-mediated adverse reactions and for selected recurrent or corticosteroid-refractory scenarios. [1]
Medication selection algorithm
Mucositis severity should be graded by CTCAE and managed with the following framework. [1]
- Pembrolizumab should be withheld for severe (grade 3) immune-mediated adverse reactions. [1]
- Pembrolizumab should be permanently discontinued for life-threatening (grade 4) immune-mediated adverse reactions. [1]
Supportive care should be provided in parallel with immune-mediated adverse event management. [1]
Key evidence supporting systemic steroid dosing and taper
KEYTRUDA prescribing information recommends systemic corticosteroid therapy at 1 to 2 mg/kg/day prednisone (or equivalent) until improvement to grade 1 or less. [1] After improvement to grade 1 or less, corticosteroid taper is recommended with tapering over at least 1 month. [1] ASCO guidance for severe immune-related cutaneous and mucosal toxicities recommends (methyl)prednisolone 1 to 2 mg/kg with tapering over at least 4 weeks for grade 3 toxicity, and recommends IV (methyl)prednisolone 1 to 2 mg/kg with tapering over at least 4 weeks when grade 4 toxicity requires inpatient-level management. [2]
Monotherapy versus combination therapy
Systemic corticosteroids should be used as initial systemic immunosuppression for immune-mediated toxicities that require systemic therapy. [1] Additional systemic immunosuppressive agents should be considered when immune-mediated adverse reactions are not controlled with corticosteroid therapy. [1]
Treatment initiation thresholds (grade-based criteria)
Pembrolizumab should be withheld for severe (grade 3) immune-mediated adverse reactions. [1] Systemic corticosteroids (prednisone 1 to 2 mg/kg/day or equivalent) should be initiated for immune-mediated adverse reactions requiring interruption or discontinuation of KEYTRUDA. [1]
Criteria for continuation versus interruption
KEYTRUDA should be continued only when mucositis severity is not severe enough to require withholding per grade-based management. [1] For severe (grade 3) immune-mediated adverse reactions, KEYTRUDA should be withheld. [1] Resumption should be considered only after clinical improvement to grade 1 or less following corticosteroid taper. [1]
Systemic corticosteroid use and taper monitoring
Systemic corticosteroid therapy should be administered at 1 to 2 mg/kg/day prednisone (or equivalent) until improvement to grade 1 or less. [1] After improvement to grade 1 or less, corticosteroid taper should be initiated and continued with tapering over at least 1 month. [1] ASCO guidance supports tapering over at least 4 weeks for grade 3 toxicity requiring systemic steroids. [2]
Indications for permanent discontinuation
KEYTRUDA should be permanently discontinued for life-threatening (grade 4) immune-mediated adverse reactions. [1] KEYTRUDA should be permanently discontinued for recurrent severe (grade 3) immune-mediated reactions that require systemic immunosuppressive treatment. [1] KEYTRUDA should be permanently discontinued for inability to reduce corticosteroid dose to 10 mg or less of prednisone (or equivalent) per day within 12 weeks of initiating steroids. [1] KEYTRUDA should be permanently discontinued for failure to achieve complete or partial resolution (grade 0 to 1 response) within 12 weeks of initiating steroids for events managed with the “withhold and resume” pathway in the prescribing information. [1]
Common pitfalls to avoid
Corticosteroids should not be tapered before clinical improvement to grade 1 or less. [1] Corticosteroid taper should not be shortened below a recommended duration of at least 1 month for KEYTRUDA-associated immune-mediated adverse reactions. [1] Pembrolizumab should not be resumed before improvement to grade 1 or less after corticosteroid taper. [1]