827P - Comparison of efficacy and safety between glofitamab and real-world regimens among Chinese patients with 3L+ relapsed/refractory diffuse large B-cell lymphoma: An external control study

Background

Treatment options are scarce for relapsed/refractory diffuse large B-cell lymphoma (DLBCL) that fails to respond to ≥2 lines of systemic therapy (3L+). The safety and efficacy of glofitamab has been reported in Chinese patients with 3L+ DLBCL in a single-arm trial.

Methods

We compare the efficacy and safety data from that Glofitamab cohort with frequently used therapies in Chinese practice (RWD cohort). The primary endpoint was the complete response rate (CRR); secondary endpoints were the overall response rate (ORR) and time-to-next treatment (TTNT); and an exploratory endpoint was the incidence of hematologic adverse events (AEs). Propensity score with inverse probability weighting was used to balance baseline covariates (age, sex, Ann Arbor stage, number of prior therapy lines, and refractory to last prior therapy). Average treatment effect on the treated weights were calculated. The odds ratio (OR) of the CRR and ORR and hazard ratio (HR) of TTNT and corresponding 95% confidence interval (CI) were obtained.

Results

In the Glofitamab and RWD cohorts, median treatment duration was 24.9 and 4.0 weeks and follow-up time was 15 and 7 months, respectively. CRR in the Glofitamab cohort was 51.9% (32.0%–71.3%), and unweighted and weighted CRRs in the RWD cohort were 9.9% (5.8%–15.5%) and 10.1% (0.0%–21.4%), respectively (weighted OR 0.104, 95% CI 0.024–0.447, P=0.0024 vs. Glofitamab cohort). In the Glofitamab and weighted RWD cohorts, ORRs were 66.7% (46.0%–83.5%) and 31.1% (13.7%–48.5%), respectively (OR 0.226, 95% CI 0.072–0.706, P=0.0105). In the Glofitamab cohort, median TTNT was not reached; 12-month probability of not initiating next treatment was 56.8% (95% CI 37.5%–76.2%). In weighted RWD cohort, median TTNT was 3.6 (2.6–5.6) months, with a 12-month probability of 28.5% (18.0%–38.9%) (HR 2.159, 95% CI 1.018–4.580, P=0.0449 vs. Glofitamab). In the Glofitamab and weighted RWD cohorts, hematologic AE incidence was 56.7% (37.4%–74.5%) and 60.9% (43.5%–78.3%).

Conclusions

Glofitamab had better efficacy and a lower percentage of hematologic AEs than frequently used therapies in Chinese patients with 3L+DLBCL.

Clinical trial identification

Editorial acknowledgement

Emily Woodhouse, PhD, of Edanz provided editorial assistance.

Legal entity responsible for the study

Shanghai Roche Pharmaceuticals Ltd was responsible for the governance, coordination, and running of this study.

Funding

Shanghai Roche Pharmaceuticals Ltd.

Disclosure

Y. Lan, J. Xu, X. Zhou: Financial Interests, Institutional, Other, Employee: Shanghai Roche Pharmaceuticals. All other authors have declared no conflicts of interest.