Pier Luigi Zinzani, MD, PhD
Nearly three-fourths of patients with relapsed/refractory primary mediastinal large B-cell lymphoma (PMBCL) responded to a combination of nivolumab (Opdivo) plus brentuximab vedotin (Adcetris), according to results from the phase I/II CheckMate-436 trial that were presented at the 15th
International Conference on Malignant Lymphoma.
At a median follow-up of 11.1 months (IQR, 9-16), 25 of 30 treated patients were eligible for response evaluation. Results showed that the overall response rate (ORR) was 73%, including 11 patients with a complete response (CR), and 10 who achieved a partial response (PR).
Reduction of target lesion was observed in 23 (92%) patients and 13 (52%) patients had a reduction >50%. Two (8%) patients had no reduction in target lesion tumor burden.
“These results suggest that brentuximab vedotin and nivolumab work synergistically to target CD30 expression and PD-L1 to provide a greater response,” said lead study author Pier Luigi Zinzani MD, PhD.
In a presentation during the meeting, Zinzani,
professor of hematology, head of Lymphoma Group, Institute of Hematology, University of Bologna in Bologna, Italy underscored the need for new treatments for relapsed/refractory PMBL.
“These patients have poor outcomes; the response to salvage chemotherapy is approximately 25% and the rate of 2-year survival after diagnosis is 15%,” he said, adding that there are no standard therapies available.
The efficacy and safety of nivolumab in combination with brentuximab vedotin have been established in phase I/II studies in relapsed/refractory classical Hodgkin lymphoma, which shares genetic features with PMBL, Zinzani explained.
“In relapsed/refractory PMBL, brentuximab vedotin and PD-1 blockade alone are associated with an ORR of 13% and 41%, respectively,” he said, noting that a combination of the 2 agents would be tolerated in patients with PMBL, and could even work synergistically to provide a greater response than seen with either drug separately.
In the open-label, phase I/II CheckMate-436 trial (NCT02581631), investigators evaluated nivolumab plus brentuximab vedotin in 30 patients with relapsed/refractory PMBL and measurable disease who had received either high-dose conditioning chemotherapy and autologous hematopoietic stem cell transplantation (AHSCT) or ≥2 multi-agent chemotherapy regimens. Since brentuximab vedotin targets CD30, patients were also required to have CD30 expression ≥1% on the tumor or on tumor-infiltrating lymphocytes.
The median age was 36 years (range, 19-83) and 57% were female. The median lines of prior therapies was 2 (range, 2 to 5), including rituximab (Rituximab; 100%), radiotherapy (27%), and AHSCT (13%). At enrollment, the majority (67%) of patients had refractory disease, 20% were relapsed, and 13% were both.
Twenty-nine patients were treated with oral nivolumab at 240 mg IV plus brentuximab vedotin at 1.8 mg/kg IV every 3 weeks; 1 patient received only brentuximab vedotin until disease progression or unacceptable toxicity.
The primary endpoints were investigator‐assessed ORR according to Lugano 2014 criteria, and safety; secondary endpoints included duration of response (DOR), CR rate, duration of CR, progression-free survival (PFS), and overall survival (OS). Assessments were made by the investigator and by blinded independent central review (BICR) as a post-hoc analysis.
At a median follow-up of 11 months, results showed that the investigator-assessed PFS was not reached (NR) and the 6-month PFS rates via investigator and BICR were 63.5% (95% CI, 42.5%-78.6%) and 73.3% (95% CI, 52.0%-86.3%), respectively.
The median DOR and duration of CR were NR. The median time to first objective response was 1.3 months (IQR, 1.3-1.6) and the median time to CR was 3.2 months (IQR, 2.5-5.6).
Of the 5 patients who were not evaluable for response, 2 had died, 1 had inconsistent tumor codes, and 2 had measurements after progression.
Subsequent to this study, 11 (50%) of the responders proceeded to undergo stem cell transplant. At the time of transplant, 6 patients remained in CR and 5 were in PR; at 100 days post-transplant, 10 (100%) patients experienced a CR and there were no PRs. One patient underwent transplant <100 days prior to the assessment and could not be included.
At the time of data cut-off, a median 5 doses of nivolumab (range, 1-22) and 5 doses of brentuximab vedotin (range, 1-20) were given. Four (13%) patients remain on treatment and 26 (87%) patients discontinued. Ten (33%) patients discontinued due to their maximum benefit being reached; other cases were due to disease progression in (27%) and toxicity (7%). One patient requested discontinuation and 3 patients stopped treatment for other reasons.