The following article features coverage from the 2021 Annual Meeting of the Society of Hematologic Oncology (SOHO). Click here to read more of Hematology Advisor‘s conference coverage.

According to updated results of an ongoing study, glofitamab monotherapy resulted high preliminary response rates in patients with relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL). The results were presented by Cyrus Khan, MD, of Allegheny Health Network Cancer Institute, Pittsburgh, PA, at the Annual Meeting of the Society of Hematologic Oncology (SOHO).

Glofitamab is a T-cell-engaging, bispecific, full-length antibody with bivalent binding to CD20 of B-cells and monovalent binding to CD3 of T-cells. The updated results derive from NP30179 (ClinicalTrials.gov Identifier: NCT03075696), a multicenter, phase 1/2, dose-escalation and expansion study evaluating safety and efficacy of glofitamab in addition to obinutuzumab in patients with R/R NHL.  

Patients received obinutuzumab (1000 mg) 7 days before the initial dose of glofitamab. Intravenous glofitamab monotherapy step-up dosing was administered on day (D) 1 and D8 of cycle (C) 1, then at the target dose from C2D1, either 2.5/10/16 mg or 2.5/10/30 mg, for up to 12 cycles, every 21 days. Response rates were assessed based on the Lugano criteria.


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At the data cut-off date (December 1, 2020), 52 patients had received glofitamab step-up dosing (2.5/10/16 mg regimen: n=17; 2.5/10/30 mg regimen: n=35). The median age was 68 years (range, 44-85). Approximately half of the patients had either aggressive NHL (aNHL; 53.8%) or indolent NHL (iNHL; 46%). The median number of prior lines of therapy was 3 (range, 1-12). Most patients were refractory to their most recent (76.9%) and any prior CD20 therapy (73.1%).

At a median follow-up duration of 6.3 months, the best overall response (OR) and complete metabolic response (CMR) rates for the aNHL cohort were 64.3% and 57.1%, with 13/16 CMRs ongoing (8 CMRs lasting >3 months; 5 CMRs lasting >6 months), and 79.2% and 70.8% for the iNHL cohort, with 16/17 CMRs ongoing (10 CMRs lasting >3 months; 3 CMRs lasting >6 months). Within the aNHL cohort, 80% of patients with mantle cell lymphoma (4/5; 2.5/10/16 mg regimen: n=2; 2.5/10/30 mg regimen: n=2) achieved CMR. Antitumor activity was observed across all NHL subtypes.

Treatment-related adverse events (TRAEs) and serious TRAEs occurred in 90.4% and 61.5% of patients. Grade 3-4 TRAEs occurred in 40.4% of patients. Common AEs/TRAEs included cytokine release syndrome (CRS) (63.5%; typically of grade 1 during C1), neutropenia (38.5%), and pyrexia (32.7%). No grade 5 events were reported.

“This step-up dosing updated analysis shows impressive responses and that partial responses can translate into a complete responses in a very heavily pretreated population, and these seem to be durable, as well as [with] manageable toxicity,” concluded Dr Khan.

Disclosure: This research was supported by F. Hoffmann-La Roche Ltd. Please see the original reference for a full list of disclosures.

Read more of Hematology Advisor’s coverage of SOHO 2021 by visiting the conference page.

Reference

Carlo-Stella C, Khan C, Hutchings M, et al. Glofitamab step-up dosing (SUD): updated efficacy data show high complete response rates in heavily pretreated relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL) patients (Pts). Paper presented at: Annual Meeting of the Society of Hematologic Oncology (SOHO); September 8-11, 2021. Abstract ABCL-360.