SC on par with IV rituximab in CD20+ diffuse large B-cell lymphoma

22 Aug 2023 bởiStephen Padilla
SC on par with IV rituximab in CD20+ diffuse large B-cell lymphoma

In patients with previously untreated CD20+ diffuse large B-cell lymphoma (DLBCL), treatment with subcutaneous (SC) rituximab is not inferior to intravenous (IV) rituximab in terms of serum trough levels, efficacy, and tolerability, as shown in a study presented at EHA 2023.

This finding suggests “that SC rituximab is a viable route of administration, with potential to reduce burden of administration for healthcare professionals and patients,” said the researchers, led by Yan Gao, internal medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.

Gao and colleagues conducted this phase II, randomized, controlled, open-label study in nine centres in China between 24 February 2021 and 23 May 2022 to examine the pharmacokinetics, efficacy, and safety of SC versus IV rituximab, both in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP).

The investigators randomized 50 patients aged between 18‒80 years with untreated CD20+ DLBCL to receive either one cycle of IV rituximab plus seven cycles of SC rituximab (RSCCHOP), or eight cycles of IV rituximab (RIV-CHOP), both in combination with six or eight cycles of CHOP every 3 weeks. They administered IV and SC rituximab at 375 mg/m2 and 1,400 mg doses, respectively.

The ratio of trough rituximab serum concentration of SC to IV formulation (Ctrough,SC/Ctrough,IV) at cycle 7 served as the primary study endpoint. Noninferiority of Ctrough,SC to Ctrough,IV was achieved if the lower limit of the two-sided 90 percent confidence interval (CI) exceeded 0.80.

The Lugano Response Criteria for Malignant Lymphoma was used to determine complete response rate (CRR), reviewed by an Independent Review Committee (IRC). The investigators also assessed other pharmacokinetics and efficacy endpoints, as well as safety, tolerability, and immunogenicity.

Of the 50 patients (median age 61.5 years) enrolled, 26 received RSC-CHOP and 24 RIV-CHOP. No significant difference was observed in baseline characteristics of International Prognostic Index (IPI) scores between the two treatment arms. Twenty-one (42.0 percent) patients had an IPI score of 3‒5. [EHA 2023, abstract PB2307]

Most of the patients in both SC (24/26, 92.3 percent) and IV (19/24, 79.2 percent) arms competed all eight cycles of rituximab. At cycle 7, the geometric mean ratio of Ctrough,SC/Ctrough,IV was 1.52 (90 percent CI, 1.28‒1.79), suggesting the noninferiority of SC to IV rituximab.

The IRC-assessed CRR was comparable between the SC rituximab arm (80.8 percent, 95 percent CI, 60.7‒93.5) and the IV arm (62.5 percent, 95 percent CI, 40.6‒81.2).

Likewise, the safety profile of SC rituximab was similar to that of IV rituximab. No new safety findings were noted, and the incidence of adverse events did not differ between the two treatment arms.

“DLBCL is the most common histologic subtype of non-Hodgkin’s lymphoma (NHL) in China, accounting for approximately 54 percent of B-cell origin NHL cases,” the investigators said.

“The standard of care for DLBCL is eight cycles of IV rituximab combined with six or eight cycles of CHOP. Since March 2014, rituximab has also been available as a solution for SC injection in various countries,” they added.