The addition of pembrolizumab to consolidation chemotherapy resulted in high response rates and was well-tolerated among pediatric patients with high-risk classic Hodgkin lymphoma (cHL) who had a slow early response (SER) to initial chemotherapy, according to the results of the phase 2 KEYNOTE-667 study presented at the EHA 2022 Hybrid Congress.
“This early data suggests that addition of pembrolizumab potentially may have the ability to augment responses in this high-risk subgroup of patients,” the authors wrote.
The open-label, phase 2 KEYNOTE-667 trial treated 30 patients with high-risk cHL and a SER to induction chemotherapy with consolidation with pembrolizumab plus cyclophosphamide, vincristine, prednisone/prednisolone, and dacarbazine (COPDAC-28).
Patients who were PET positive after completing consolidation received modified involved-site radiation therapy (RT), whereas PET-negative patients did not undergo RT. The primary endpoint was objective response rate by BICR criteria among patients with SER. Secondary endpoints included the rate of PET-negativity and safety.
At baseline, the median age was 15 years, 43% of patients had bulky disease, and 63% had Ann Arbor stage IV disease. During a median follow-up of 9.6 months, the PET-negative rate was 68% among the 25 patients with late response assessment.
Treatment-related adverse events developed among 47% of patients, including 7% developing grade 3 or higher severity. A grade 2 immune-mediated hypothyroidism occurred in 1 patient.
The authors concluded that “in pediatric patients with high-risk cHL and SER to standard OEPA induction, pembrolizumab in combination with COPDAC-28 consolidation therapy was well tolerated and resulted in 68% of patients having a PET-negative response at the end of chemo, and being spared RT.”
Disclosures: Disclosures are not available for this presentation.
Vinti L, Daw S, Alvarez CS, et al. Pembrolizumab in children and young adults with newly diagnosed classical Hodgkin lymphoma with slow early response to frontline chemotherapy: the phase 2, open-label, KEYNOTE-667 study. Presented at EHA 2022; June 9-12, 2022. Abstract S204.