Daw, Stephen

ImportanceRetrieval strategies for children, adolescents, and young adults with relapsed classic Hodgkin lymphoma (cHL) aim to maintain efficacy while minimizing long-term toxic effects. Children, adolescents, and young adults with low-risk, relapsed cHL may benefit from replacing high-dose chemotherapy and autologous stem cell transplant with less intensive involved-site radiotherapy (ISRT).ObjectiveTo evaluate a risk-stratified, response-adapted, transplant-free approach for treatment of children, adolescents, and young adults with low-risk relapsed cHL with nivolumab plus brentuximab vedotin (BV) followed by BV plus bendamustine for patients with suboptimal response and ISRT (30.0 to 30.6 Gy).Design, Setting, and ParticipantsCheckMate 744 (R1 cohort) was a phase 2, nonrandomized, single-arm study enrolling children, adolescents, and young adults aged 5 to 30 years with low-risk cHL between September 25, 2017, and December 16, 2020, across the US, Canada, and Europe. Data were analyzed from September 2017 to November 2022.ExposuresPatients received 4 cycles of nivolumab plus BV induction; patients with complete metabolic response (CMR) received an additional 2 cycles of nivolumab plus BV while patients with suboptimal response received 2 cycles of BV plus bendamustine intensification. Patients with CMR after induction or intensification received ISRT consolidation.Main Outcomes and MeasuresPrespecified coprimary end points were CMR rate (Lugano 2014 classification) any time before ISRT and 3-year event-free survival (EFS) rate, per blinded independent central review (BICR).ResultsOf 28 included patients treated in the low-risk cohort, 18 (64%) were female, and the median (range) age was 17 (6-27) years. At a median (range) follow-up of 31.9 (2.2-55.3) months, CMR per BICR any time before ISRT was 93% (26 of 28; 90% CI, 79.2-98.7; objective response rate [ORR], 100%), and 23 of 28 (82%) achieved CMR per BICR after 4 cycles of nivolumab plus BV (ORR, 96.4%). Kaplan-Meier estimates of EFS and progression-free survival rates at 3 years were 87% (3 of 18; 90% CI, 69.5-94.7) and 95% (1 of 18; 90% CI, 76.7-99.0), respectively. During induction, 22 patients (79%) had treatment-related adverse events, including 7 with grade 3 or 4 adverse events, 2 with anemia, 1 with neutropenia, and 6 with immune-mediated adverse events. Serious adverse events leading to discontinuation occurred in 2 patients.Conclusions and RelevanceThis nonrandomized clinical trial found that for children, adolescents, and young adults with low-risk, relapsed cHL, a transplant-free, risk-adapted, response-based approach with nivolumab plus BV and ISRT offered high CMR rates and high 3-year EFS rate, with a safety profile consistent with that of each agent used.Trial RegistrationClinicalTrials.gov Identifier: NCT02927769

Background: Overall survival rates now exceed 90% for children, adolescents, and young adults with cHL, but patients with slow early response (SER) to front-line chemotherapy are at an increased risk of relapse. The approaches used historically to treat patients with SER included dose intensification and radiotherapy (RT), which can be associated with long-term toxicity. The open-label, phase 2 KEYNOTE-667study (NCT03407144) is designed to evaluate the efficacy and safety of consolidation with pembrolizumab plus chemotherapy with or without RT followed by pembrolizumab maintenance in patients with cHL and SER to front-line chemotherapy. The study includes 2 groups: patients with low-risk cHL (stage IA, IB, or IIA without bulky disease) and patients with high-risk cHL (stage IIEB-IVB). Prior analysis of the high-risk group showed that consolidation with pembrolizumab plus cyclophosphamide, vincristine, prednisone/prednisolone, and dacarbazine (COPDAC-28) followed by pembrolizumab maintenance had manageable safety and promising activity in patients with high-risk cHL and SER to front-line vincristine, etoposide, prednisone/prednisolone, and doxorubicin (OEPA). Here, we present updated results for patients with high-risk cHL and SER to OEPA. Methods: Patients eligible for the high-risk group were aged 3-25 years and had newly diagnosed stage IIEB, IIIEA, IIIEB, IIIB, IVA, or IVB cHL; measurable disease; and a Lansky Play-Performance Scale (aged <16 years) or a Karnofsky Performance Status (aged ≥16 years) score of ≥50. All patients in the high-risk group received 2 cycles of OEPA followed by early response assessment (PET and CT/MRI). Patients with a rapid early response (ie, Deauville score [DS] 1-3) received nonstudy therapy. Patients with a SER (ie, DS 4 or 5) received consolidation therapy with pembrolizumab 2 mg/kg up to 200 mg (aged 3-17 years) or 200 mg (aged 18-25 years) IV Q3W plus COPDAC-28 for 4 cycles. Patients then underwent late-response assessment (LRA; PET and CT/MRI). Patients with PET-positive disease at LRA (ie, DS 4 or 5) received RT (28.8 Gy) to late PET-positive residua. Patients with PET-negative disease (ie, DS 1-3) received no RT. All patients received maintenance pembrolizumab for up to 17 cycles. The primary end point was objective response rate (ORR) by blinded independent central review (BICR) per Cheson 2007 IWG criteria. Secondary end points included the rate of PET negativity after consolidation and safety. Results: 84 patients with high-risk cHL and SER to front-line OEPA received consolidation with pembrolizumab plus COPDAC-28. Median time from treatment allocation to data cutoff (Feb 29, 2024) was 24.3 months (range, 5.7-48.4). As of the data cutoff, 55 patients had completed consolidation and maintenance therapy, 20 were ongoing, and 9 had discontinued treatment (due to adverse events [AE], n = 3; progressive disease, n = 2; withdrawal by patient, n = 2; complete response [CR], n = 1; physician decision, n = 1). Patients received a median of 17 doses of pembrolizumab (range, 2-17) and the median time on pembrolizumab was 11.1 months (range, 0.5-11.8). The median age of patients was 14 years (range, 4-22), 78 (93%) were aged 3-17 years, 45 (54%) were male, 44 (52%) had bulky disease, and 53 (63%) had Ann Arbor stage IV disease. Of 84 patients who received consolidation, 80 (95%) had an LRA. The ORR among these patients was 99% (95% CI, 93-100; 57 CR and 22 partial response). 56 patients (70%) with a LRA were PET negative by BICR; 55 (69%) were PET negative by investigator review and did not receive RT. Treatment-related AEs were reported in 61 patients (73%); grade 3 or 4 treatment-related AEs occurred in 16 patients (19%). Three patients (4%) discontinued treatment due to treatment-related AEs. No patients died due to treatment-related AEs. Immune-mediated AEs occurred in 10 patients (12%). Conclusion: After additional follow up, consolidation with pembrolizumab plus COPDAC-28 with or without RT followed by pembrolizumab maintenance continued to demonstrate promising activity and manageable safety in patients with high-risk cHL and SER to front-line OEPA. Among the 80 patients with an LRA, 70% were PET negative by BICR and 69% were PET negative by investigator review and were spared RT. These results continue to support pembrolizumab plus COPDAC-28 consolidation as a treatment option that may augment response in patients with high-risk CHL and SER to front-line OEPA.

Background: cHL is one of the most curable forms of childhood cancer, but patients (pts) who have a SER to initial chemo are at high risk of relapse. The approaches currently used to treat pts with SER, such as dose intensification and radiotherapy (RT), can cause long-term toxicity.An unmet need remains to optimize treatment in pts with cHL and SER while minimizing long-term toxicity. The open-label, phase 2 KEYNOTE-667 study (NCT03407144) is being conducted to evaluate the efficacy and safety of pembro plus chemo in pediatric pts with cHL and SER to front-line chemo. Early analysis of pts in KEYNOTE-667 with high-risk cHL showed that pembro plus cyclophosphamide, vincristine, prednisone/prednisolone, and dacarbazine (COPDAC-28) consolidation had manageable safety and promising antitumor activity, with 66% of pts being spared RT. We present updated results for pts with high-risk cHL and SER. Methods: Pts eligible for the high-risk group were 3-25 y old and had newly diagnosed stage IIEB, IIIEA, IIIEB, IIIB, IVA, or IVB cHL, measurable disease per investigator assessment, and a Lansky Play-Performance Scale ≥50 (<16 y old) or a Karnofsky score ≥50 (≥16 y old). All pts received 2 cycles of induction therapy with vincristine, etoposide, prednisone/prednisolone, and doxorubicin (OEPA). After induction, response was assessed by PET/MRI/CT (early response assessment). Pts with rapid early response received nonstudy therapy. Pts with SER (Deauville score, 4 or 5) received consolidation with pembro 2 mg/kg up to 200 mg IV Q3W (3-17 y) or 200 mg IV Q3W (18-25 y) plus 4 cycles of COPDAC-28. Response was then assessed by PET/CT/MRI (late response assessment [LRA]). Pts with PET positivity at LRA (Deauville score, 4 or 5) received involved-site RT (28.8 Gy) to late PET-positive residua plus maintenance pembro Q3W for up to 17 cycles; pts with PET negativity received maintenance pembro Q3W for up to 17 cycles without RT. The primary end point was ORR by BICR per Cheson 2007 IWG criteria in pts with SER, determined at any time after starting pembro and before start of new anticancer therapy. Secondary end points included PET negativity after consolidation, EFS, OS, and safety. Results: This analysis included 62 pts with high-risk cHL and SER to frontline OEPA. The median time from enrollment to data cutoff (March 1, 2023) was 16.8 mo (range, 2.3-36.4). At the data cutoff, 34 pts (55%) had completed consolidation and maintenance therapy, 23 (37%) were ongoing on treatment, and 5 (8%) had discontinued because of adverse events (AEs; n = 1), progressive disease (n = 2), or withdrawal by pt (n = 2). Median age was 14 y (range, 5-22), 30 pts (48%) were male, 29 (47%) had bulky disease, and 41 (66%) had Ann Arbor stage IV disease. Pts had received a median of 17 administrations of pembro (range, 1-17); the median time on pembro was 11.0 mo (range, <0.1-11.8). Of 62 pts who received consolidation with pembro plus COPDAC-28, 53 (85%) had a LRA (9 are still in consolidation and have not reached the LRA time point), of whom 35 (66%) were PET negative by BICR (37 [70%] PET negative by investigator review). AEs regardless of causality that occurred during consolidation and maintenance were reported in 54 pts (87%), most commonly (≥15%) headache (n = 11; 18%), nausea (n = 11; 18%), cough (n = 10; 16%), COVID-19 (n = 10; 16%), and pyrexia (n = 10; 16%). Grade 3/4 AEs occurred in 21 pts (34%). 13 pts (21%) had a serious AE. No pts died because of AEs. Treatment-related AEs occurred in 38 pts (61%). Grade 3/4 treatment-related AEs occurred in 10 pts (16%). One pt (2%) discontinued treatment because of a treatment-related AE (grade 3 AST increased). Pembro-related AEs occurred in 23 (37%) pts; most commonly (≥5%) hypothyroidism (n = 4; 6%), nausea (n = 3; 5%), and ALT increased (n = 3; 5%). Three pts (5%) experienced grade 3/4 pembro-related AEs. One serious AE was related to pembro (abdominal pain). Six pts (10%) experienced immune-mediated AEs (hypothyroidism, n = 4 [2 grade 1, 2 grade 2]; colitis, n = 1 [grade 2]; pneumonitis, n = 1 [grade 2]). Conclusion: In this updated analysis, consolidation with pembro plus COPDAC-28 continued to have manageable safety and promising antitumor activity in pediatric pts with high-risk cHL and SER to front-line OEPA. Of pts with a LRA, 66% had a PET-negative response and were spared RT. These findings support the results of prior analyses and suggest that adding pembro to COPDAC-28 consolidation may augment responses in the high-risk cHL population.

7515 Background: Outcomes are poor for patients (pts) with cHL who develop R/R disease after first-line (1L) chemotherapy ± radiotherapy (RT). Salvage tx that attain high event-free survival (EFS) rates and minimize late toxicity by omitting high-dose chemotherapy (HDCT)/auto-HCT are needed. CheckMate 744 (NCT02927769) is the first multicenter phase 2 study evaluating a risk-stratified, response-adapted salvage tx with nivo + BV in CAYA with R/R cHL. In the standard-risk cohort, complete molecular response (CMR) rate before consolidation with HDCT/auto-HCT was 94% (Harker-Murray et al. Blood 2022). With highly active salvage tx, pts in low-risk cohort could achieve high EFS without HDCT/auto-HCT; we report data from this cohort. Methods: Pts were aged 5–30 y and had ≤ 3 cycles (C) of 1L anthracycline-based systemic tx. Risk stratification was described in Harker-Murray et al. Pts received 4C of nivo + BV induction. Pts with CMR received additional 2C nivo + BV before involved-site radiation therapy (ISRT) consolidation (dose, 30–30.6 Gy). Pts with suboptimal response received 2C BV + bendamustine intensification; pts with CMR proceeded to ISRT consolidation. Primary endpoints: CMR rate (Lugano 2014) any time before ISRT and 3-y EFS rate, both per blinded independent central review (BICR). For CMR and overall response rate (ORR), a 90% confidence interval (CI) was used per statistical plan. Results: Among 28 pts treated with nivo + BV, median (range) age was 17 (6–27) y; 64% of pts were aged < 18 y. Most (64%) pts had stage II disease at relapse; 82% had relapse ≥ 12 mo after 1L tx, 2 pts had prior RT. Median (range) follow-up was 31.9 (2.2–55.3) mo. CMR, ORR, 3-y EFS and PFS rates are shown in Table. Median duration of response was not reached; 87% of pts had sustained response at 36 mo’ follow-up. Efficacy outcomes were comparable in the pediatric population (CMR per BICR before ISRT, 88.9%; 3-y EFS rate, 78.3%). During induction, 22 (78.6%) pts had treatment-related adverse events (TRAEs; grade 3/4, 25.0% pts; hematologic, < 10% pts; immune-mediated, 21.4%). Serious AEs leading to discontinuation included rash, pyrexia, and acute kidney injury (1 pt each). Conclusions: The findings demonstrate that most CAYA with low-risk R/R cHL can be salvaged with chemoimmunotherapy with a favorable toxicity profile, and do not require HDCT/auto-HCT. Clinical trial information: NCT02927769 . [Table: see text]

Children, adolescents, and young adults (CAYA) with relapsed/refractory classical Hodgkin lymphoma (cHL) without complete metabolic response (CMR) before autologous hematopoietic cell transplantation (auto-HCT) have poor survival outcomes. CheckMate 744, a phase 2 study for CAYA (aged 5-30 years) with relapsed/refractory cHL, evaluated a risk-stratified, response-adapted approach with nivolumab plus brentuximab vedotin (BV) followed by BV plus bendamustine for patients with suboptimal response. Risk stratification was primarily based on time to relapse, prior treatment, and presence of B symptoms. We present the primary analysis of the standard-risk cohort. Data from the low-risk cohort are reported separately. Patients received 4 induction cycles with nivolumab plus BV; those without CMR (Deauville score &gt;3, Lugano 2014) received BV plus bendamustine intensification. Patients with CMR after induction or intensification proceeded to consolidation (high-dose chemotherapy/auto-HCT per protocol). Primary endpoint was CMR any time before consolidation. Forty-four patients were treated. Median age was 16 years. At a minimum follow-up of 15.6 months, 43 patients received 4 induction cycles (1 discontinued); 11 of whom received intensification, 32 proceeded to consolidation. CMR rate was 59% after induction with nivolumab plus BV, and 94% any time before consolidation (nivolumab plus BV ± BV plus bendamustine). One-year PFS rate was 91%. During induction, 18% of patients experienced grade 3/4 treatment-related adverse events. This risk-stratified, response-adapted salvage strategy had high CMR rates with limited toxicities in CAYA with relapsed/refractory cHL. Most patients did not require additional chemotherapy (bendamustine intensification). Additional follow-up is needed to confirm durability of disease control. ClinicalTrials.gov: NCT02927769.