Trial-in-Progress: Brentuximab Vedotin in Combination with Lenalidomide and Rituximab in Subjects with Relapsed or Refractory Diffuse Large B-Cell Lymphoma (DLBCL)

Background

Majority of patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who relapse after HSCT, or who are not candidates for HSCT have poor outcomes and are in need of novel therapies. Preclinical data provides a strong rationale for combining brentuximab vedotin, lenalidomide, and rituximab in the treatment of R/R DLBCL. In a phase 1 trial, 37 subjects with R/R DLBCL were treated with brentuximab vedotin in combination with lenalidomide. The objective response rate (ORR) (proportion of subjects with complete response [CR] or partial response [PR]) for all subjects was 56.7% (21 of 37 subjects). For the CD30-positive population, the ORR was 73.3% (11 of 15 subjects), whereas the ORR for the CD30 <1% population was 45.6% (10/22). The median follow-up time was 14.3 months (range: 1 to 56.7 months). The median duration of remission for subjects with CR or PR was 13.2 months (range: 3.2 to 55.2 months). For subjects with CR, PR, or stable disease (SD) >6 months, the median duration of remission was 11.70 months (range: 3.2 to 55.2 months). The progression-free survival (PFS) and overall survival (OS) results appear similar in both the CD30-positive and CD30 <1% groups. The PFS in the combined population is 10.2 months and the median OS is 14.2 months (manuscript in preparation).

Study Design and Methods

This is a randomized, double-blind, placebo-controlled, active-comparator, multicenter phase 3 study designed to evaluate the efficacy of brentuximab vedotin in combination with lenalidomide and rituximab versus placebo in combination with lenalidomide and rituximab for the treatment of subjects with R/R DLBCL (NCT04404283).

Key eligibility criteria include the following: subjects aged 18 and older with R/R DLBCL with an eligible subtype; subjects must have ≥2 prior lines of therapy and must be ineligible for, or have declined, stem cell transplant, and chimeric antigen receptor T-cell (CAR-T) therapy; subjects must have an ECOG performance status score of 0 to 2; subjects must have a fluorodeoxyglucose-avid disease by PET and bidimensional measurable disease of at least 1.5 cm by CT, as assessed by the site radiologist.

Subjects (n=400) will be randomized 1:1 to receive either brentuximab vedotin or placebo in combination with lenalidomide and rituximab and will be stratified by CD30 expression (positive [ ≥1%] versus <1%), prior allogeneic or autologous stem cell transplant therapy (received or not), prior CAR-T therapy (received or not), and cell of origin (germinal-center B-cell-like (GCB) or non‑GCB). Cell of origin (GCB or non-GCB) will be histologically determined by local pathology assessment.

Disease response will be assessed by a blinded independent central review (BICR) and the investigator according to the Lugano Classification Revised Staging System. Radiographic disease evaluations, including contrast-enhanced CT scans and PET/CT, will be assessed at baseline, then every 6 weeks from randomization for 12 months, then every 12 weeks (±3 days). PET/CTs will be discontinued if negative.

For the primary efficacy analyses of PFS per BICR in the intent-to-treat population and in CD30‑positive subjects, the stratified log-rank test will be used to compare PFS between the 2 treatment groups. The hazard ratio will be estimated using a stratified Cox regression model. PFS will also be summarized using the Kaplan-Meier method. Similar methods will be used for the secondary efficacy endpoint of OS, and other time-to-event efficacy endpoints.

The trial will have sites open in the US and multiple countries in Europe and Asia, with enrollment planning to begin in the second half of 2020.