Subcutaneous rituximab when used in induction followed by a short maintenance improves progression-free survival (PFS) in patients with low-tumor burden follicular lymphoma (FL), according to research published in the Journal of Clinical Oncology.
Researchers conducted a randomized phase 3 clinical trial (ClinicalTrials.gov Identifier: NCT02303119) comparing the use of a short subcutaneous rituximab maintenance after a subcutaneous rituximab induction vs standard 4 weekly intravenous rituximab infusions in patients with histologically confirmed CD20+ low-tumor burden FL.
In the control arm, 102 patients (median age, 59.5 years; range, 33-80; 44% male and 56% female) received standard intravenous rituximab (375 mg/m2 once daily on Day (D) 1, D8, D15, and D22; control arm). In the experimental arm, 100 patients (median age, 59.0 years; range, 32-85; 56% male and 44% female) received intravenous rituximab (375 mg/m2) on D1 followed by 7 administrations of subcutaneous rituximab once daily on D8, D15, and D22, with maintenance at months 3, 5, 7, and 9 (1400 mg total dose; experimental arm).
The primary endpoint was PFS. Secondary endpoints included safety, overall response rates, time to next treatment (TTNT), and overall survival (OS).
The study met its primary endpoint with a 4-year PFS of 58.1% (95% CI, 47.5-67.4) in the experimental arm compared with 41.2% (95% CI, 30.6-51.6) in the control arm (hazard ratio, 0.585; 95% CI, 0.393-0.871; P =.0076).
The complete response rate was higher in the experimental arm than in the control arm (59.0% vs 36.3%; P =.001). No significant differences in TTNT and OS were observed between the arms.
The study found high rituximab exposure during the first 3 months was independently associated with higher CR, PFS, and TTNT.
“Our study clearly demonstrates that rituximab exposure during the first 3 months is an independent parameter influencing response and survival outcomes. In this regard, SC rituximab used as induction allows us to improve rituximab exposure and can be considered by physicians and patients as an optimal option for low–tumor burden FL,” the study authors concluded in their report.
Limitations of the study included that it was likely underpowered to detect a difference in TTNT; the influence rituximab in the first 3 months on CR at month 12, PFS, and TTNT was observed independently to treatment, suggesting rituximab maintenance may not be useful if rituximab induction is dosed appropriately.
Additionally, the investigators noted that increased exposure to rituximab observed in the experimental arm may be related to the dosage allowed by the subcutaneous route than by the route itself, and thus similar results may be achievable with appropriate dosage using the intravenous route.
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of authors’ disclosures.
Cartron G, Bachy E, Tilly H, et al. Randomized phase III trial evaluating subcutaneous rituximab for the first-line treatment of low-tumor burden follicular lymphoma: Results of a LYSA study. J Clin Oncol. Published online April 18, 2023. doi:10.1200/JCO.22.02327