Seagen Inc. announced updated efficacy and safety results from Part C of a phase 2 single-arm trial (SGN35-027) evaluating the antibody-drug conjugate ADCETRIS® (brentuximab vedotin) in combination with the PD-1 inhibitor nivolumab and standard chemotherapy agents doxorubicin and dacarbazine (AN+AD) for the frontline treatment of patients with early-stage classical Hodgkin lymphoma (cHL). Also, to be presented in a late-breaking session, are three-year results from a 1,500-patient phase 3 trial from the German Hodgkin Study Group (HD21) evaluating non-inferiority efficacy and potential for reduced toxicity of an ADCETRIS regimen (BrECADD) compared to the highly efficacious yet chemotherapy intensive escalated BEACOPP regimen, commonly used outside of the U.S. The study will be presented on June 17, 2023. ADCETRIS + AVD chemotherapy (Adriamycin, vinblastine, dacarbazine) is a U.S. standard of care in advanced-stage cHL based on national treatment guidelines and is the only targeted therapy inclusive regimen that has a proven statistically significant overall survival benefit at 6-years of follow-up, reducing risk of death by 41% for these patients.

ADCETRIS is approved for seven indications in the U.S. and five indications in Europe, where Takeda has commercialization rights. Of 154 patients with early-stage disease in Part C of the study, 150 were included at the time of efficacy assessment, showing: A 98% ORR (95% CI: 94.3, 99.6) and a 93% CR rate (95% CI: 87.3, 96.3) at end of treatment (EOT). Follow-up is ongoing and progression-free survival (PFS) results are not yet available.

The most frequently reported treatment-related treatment-emergent adverse events (TRAEs) of any grade occurring in more than 30% of patients were nausea (65%), peripheral sensory neuropathy (47%) and fatigue (44%). Peripheral sensory neuropathy was primarily low grade (3% Grade =3). There were no cases of febrile neutropenia.

Immune-mediated AEs observed to date are consistent with the individual safety profile of nivolumab. There were no grade 5 adverse events. Updated data results from Part B of the study in patients with advanced-stage disease (n=57) were presented at the European Hematology Association 2023 Congress in Frankfurt, Germany June 8-11, which showed an estimated 95% 12-month PFS rate and 93% 18-month PFS rate, an ORR of 95% and CR rate of 89% at EOT.

The most frequently reported TRAEs of any grade occurring in more than 30% of patients were nausea (65%), fatigue (49%), peripheral sensory neuropathy (44%) and alopecia (35%).