Pembrolizumab (Head and Neck SCC)

Verbatim §4.2: 'The recommended dose of KEYTRUDA in adults is either 200 mg every 3 weeks or 400 mg every 6 weeks administered as an intravenous infusion over 30 minutes.' Source product is KEYTRUDA 25 mg/mL concentrate for solution for infusion (intravenous formulation only; not to be substituted for or with subcutaneous pembrolizumab, which has different recommended dosages and routes). Therapy must be initiated and supervised by specialist physicians experienced in the treatment of cancer. HNSCC-SPECIFIC REGIMEN (§4.2): for the neoadjuvant and adjuvant treatment of resectable locally advanced HNSCC, treat with neoadjuvant pembrolizumab as monotherapy for 2 doses of 200 mg every 3 weeks or 1 dose of 400 mg, or until disease progression that precludes definitive surgery or unacceptable toxicity; followed by adjuvant pembrolizumab in combination with radiation with or without concomitant cisplatin for 3 doses of 200 mg every 3 weeks or 2 doses of 400 mg every 6 weeks; followed by pembrolizumab as monotherapy for 12 doses of 200 mg every 3 weeks or 6 doses of 400 mg every 6 weeks, or until disease recurrence or unacceptable toxicity. Patients who experience disease progression precluding definitive surgery, or unacceptable toxicity related to neoadjuvant monotherapy, should not receive the adjuvant combination. For use in combination, see the SmPC for the concomitant therapies. Otherwise treat until disease progression or unacceptable toxicity (and up to the maximum duration of therapy if specified for the indication); continue treatment in clinically stable patients with initial evidence of progression until progression is confirmed. Patient selection by tumour PD-L1 expression (and by MSI-H/dMMR status) must be confirmed by a validated test where specified in the indication. NO DOSE REDUCTIONS are recommended - withhold or permanently discontinue to manage adverse reactions per Table 1 (e.g. pneumonitis Grade 2 withhold until recovery to Grade 0-1, Grades 3 or 4 or recurrent Grade 2 permanently discontinue; colitis Grades 2 or 3 withhold, Grade 4 or recurrent Grade 3 permanently discontinue; nephritis Grade 2 with creatinine >1.5 to <=3 x ULN withhold, Grade >=3 with creatinine >3 x ULN permanently discontinue; Grade 2 adrenal insufficiency and hypophysitis withhold until controlled by hormone replacement). Table 1 is truncated in the fetched extract - consult the full SPC. When given with intravenous chemotherapy, pembrolizumab should be administered first. Elderly: no dose adjustment in patients aged 65 years and over. PAEDIATRIC (deliberately NOT structured, off-indication for this page): §4.2 states 'The recommended dose of KEYTRUDA as monotherapy in paediatric patients aged 3 years and older with cHL or patients aged 12 years and older with melanoma is 2 mg/kg bodyweight (bw) (up to a maximum of 200 mg), every 3 weeks administered as an intravenous infusion over 30 minutes.' That per-kg dose applies ONLY to cHL and melanoma - §4.2 also states 'The safety and efficacy of KEYTRUDA in children below 18 years of age have not been established except in paediatric patients with melanoma or cHL', so it must not be applied to head and neck SCC; refer to the specialist paediatric oncology protocol. §4.5 (interactions) is not present in the fetched bundle, so no interactions list is given here. || PRIOR HOLD (adversarial verify pass, retained): that pass judged the ADULT dose clean on all axes ('200 mg every 3 weeks or 400 mg every 6 weeks administered as an intravenous infusion over 30 minutes' is verbatim §4.2; correct drug, correct IV route, mg units, single agent) and held only on the paediatric field being populated with an off-indication 2 mg/kg cHL/melanoma dose, stating that nulling paedDose and redirecting to the specialist protocol would clear the hold. paedDose is null here.