CHICAGO – A six-drug combination produced complete responses in previously untreated, high-risk diffuse large B-cell lymphoma (DLBCL) patients in a phase 2 trial.
Induction with durvalumab and R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) produced complete response rates of 54% in the entire cohort and 41% in patients with double- or triple-hit lymphoma. Immune-related adverse events (AEs) were common with this regimen, but no unexpected AEs occurred, according to researchers.
of the Mayo Clinic in Rochester, Minn., and colleagues presented these results in a poster at the annual meeting of the American Society of Clinical Oncology.
The phase 2 trial () was designed to assess durvalumab plus R-CHOP as well as durvalumab plus R-CHOP and lenalidomide (R2-CHOP) in patients with previously untreated, high-risk DLBCL. However, the R2-CHOP arm was closed early.
In cycle one, all patients received durvalumab plus R-CHOP. For subsequent cycles, patients with activated B-cell (ABC) DLBCL were assigned to durvalumab plus R2-CHOP, while patients with non-ABC DLBCL continued on durvalumab plus R-CHOP.
The R2-CHOP arm was closed early due to safety issues observed in trials combining checkpoint inhibitors with immunomodulatory agents. A partial clinical hold was placed on the R2-CHOP arm, but patients could continue on the regimen if they experienced a clinical benefit. Any patients with ABC DLBCL who were enrolled after the partial hold received treatment with durvalumab plus R-CHOP.
Induction was given for up to eight cycles and was followed by consolidation with durvalumab alone for up to 12 months from the start of induction.
The researchers presented data on 43 patients in the durvalumab plus R-CHOP arm. The patients’ median age was 62 years, and 61% were men.
“I think it’s worth noting that 46% of patients in the durvalumab plus R-CHOP group had very high-risk features, including double-hit or triple-hit genetic features,” said, of the University of Chicago Medicine who reviewed this study in a poster discussion session.
Specifically, 30% of patients had double-hit lymphoma, and 16% had triple-hit lymphoma. Most patients had a high-intermediate-risk (49%) or high-risk (21%) International Prognostic Index score, and 79% of patients had Ann Arbor stage IV disease.
As of Aug. 2, 2018, 70% of patients had completed induction, 2% had completed consolidation, 44% remained on treatment, and 54% had discontinued therapy. The most common reasons for stopping treatment were progression (16%), AEs (14%), and consent withdrawal (12%).
“The combination of durvalumab plus R-CHOP demonstrated encouraging response rates … in subjects with high-risk DLBCL, including double- and triple-hit lymphomas,” Dr. Kline said.
The complete response rate was 54% (20/37) at the end of induction and 68% (n = 25) at the end of consolidation. The partial response rate at the end of consolidation was 30% (n = 11).
In patients with double- or triple-hit lymphoma, the complete response rate at the end of induction was 41% (7/17). The overall response rate in this group was 88% (n = 15).