Progression is “uncommon” in patients with relapsed/refractory large B-cell lymphoma (LBCL) who are in complete remission (CR) at the end of treatment with glofitamab, according to a presentation at the 2022 ASH Annual Meeting.
“[T]he progression-free survival in patients in CR at the end of treatment is more than 90% after 1 year of follow-up, and the estimated rate of patients with a CR lasting a minimum of 2 years is almost 80%,” said study presenter Martin Hutchings, MD, PhD, of Rigshospitalet in Copenhagen, Denmark.
These results come from a phase 1/2 study (ClinicalTrials.gov Identifier: NCT03075696) that included 291 adults with relapsed/refractory LBCL. Patients were pretreated with obinutuzumab to mitigate the risk of cytokine release syndrome.
The patients received glofitamab at either a fixed dose, ranging from 0.6 mg to 25 mg, or they received step-up dosing during cycle 1, with a target dose of 16 mg or 30 mg. Glofitamab was given every 3 weeks for a maximum of 13 infusions. However, patients could receive retreatment if their disease progressed during follow-up.
The overall response rate was 52.6%, and the CR rate was 35.4%. The median time to first CR was 43 days.
A total of 61 patients who remained in CR at the end of treatment entered the long-term follow-up. These patients had a median age of 67 years (range, 22-85). They had previously received a median of 3 lines of therapy (range, 2-9), 42.6% had primary refractory disease, and 73.8% had disease that was refractory to their last therapy.
Overall, 79% of patients were still in CR at 6 months, and 61% were still in CR at 12 months. However, 13% of patients had not reached 6 months of follow-up, and 28% had not reached 12 months of follow-up.
At 12 months, 1 patient had progressive disease, 2 had a lymphoma-related death, and 4 discontinued the study due to receipt of allogeneic transplant (n=2), physician decision (n=1), or loss to follow-up (n=1).
Of the patients who were still in CR at 12 months, 2 had disease progression after that time point. Both patients restarted glofitamab and achieved a CR again.
Although most patients did not have follow-up beyond 24 months, there was evidence of CR maintenance through 42 months.
Overall, the median duration of CR and median progression-free survival were not reached. The estimated 24-month CR rate was 79.1%, and the estimated 12-month progression-free survival rate was 92.6%.
“Off-treatment progression is uncommon in these heavily pretreated patients who were highly refractory and who are in CR at the end of treatment,” Dr Hutchings said.
Results from this study were also published in The New England Journal of Medicine.2
Disclosures: This research was supported by Hoffmann-La Roche. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
1. Hutchings M, Carlo-Stella C, Morschhauser F, et al. Relapse is uncommon in patients with large B-cell lymphoma who are in complete remission at the end of fixed-course glofitamab treatment. Presented at ASH 2022. December 10-13, 2022. Abstract 441.
2. Dickinson MJ, Carlo-Stella C, Morschhauser F, et al. Glofitamab for relapsed or refractory diffuse large B-cell lymphoma. N Engl J Med. Published online December 11, 2022. doi:10.1056/NEJMoa2206913