This is a two-part study of pembrolizumab (MK-3475) in paediatric participants who have any of the following types of cancer:
- advanced melanoma (6 months to <18 years of age),
- advanced, relapsed or refractory programmed death-ligand 1 (PD-L1)-positive malignant solid tumour or other lymphoma (6 months to <18 years of age),
- relapsed or refractory classical Hodgkin lymphoma (rrcHL) (3 years to <18 years of age) or
- advanced relapsed or refractory microsatellite-instability-high (MSI-H) solid tumours (6 months to <18 years of age) or
- advanced relapsed or refractory tumour-mutational burden-high ≥10 mutation/Mb (TMB-H) solid tumours (6 months to <18 years of age)
Part 1 will find the maximum tolerated dose (MTD)/maximum administered dose (MAD), confirm the dose and find the recommended Phase 2 dose (RP2D) for pembrolizumab therapy. Part 2 will further evaluate the safety and efficacy at the paediatric RP2D.
The primary hypothesis of this study is that intravenous (IV) administration of pembrolizumab to children with either advanced melanoma; a PD-L1 positive advanced, relapsed or refractory solid tumour or other lymphoma; advanced, relapsed or refractory MSI-H solid tumour; or rrcHL, will result in an Objective Response Rate (ORR) greater than 10% for at least one of these types of cancer. The 10% assessment does not apply to the MSI-H and TMB-H cohorts.
With Amendment 8, enrolment of participants with solid tumours and participants aged 6 months to <12 years with melanoma were closed. Enrolment of participants aged ≥12 years to ≤18 years with melanoma continues. Enrolment of participants with MSI-H and TMB-H solid tumours also continues.