Radioimmunotherapy Tops ASCT in R/R Follicular Lymphoma

TOPLINE:

With lower toxicity and equal efficacy, radioimmunotherapy is a better option than autologous stem cell transplant (ASCT) for relapsed /refractory follicular lymphoma consolidation, new data show.

METHODOLOGY:

• ASCT and radioimmunotherapy with rituximab are both widely used for relapsed/refractory follicular lymphoma consolidation.
• Some guidelines recommend ASCT as more effective, but the assertion is based largely on a 2003 trial conducted in the pre-rituximab era.
• To help settle which option is best, the FLAZ12 trial randomly assigned 70 patients to receive ASCT and 71 to receive radioimmunotherapy between 2012 and 2019; radioimmunotherapy included rituximab and 90Y-ibritumomab tiuxetan.
• Patients had had relapse after or were refractory to three courses of conventional chemoimmunotherapy that included rituximab; after consolidation, they all received rituximab maintenance therapy. More than half of the patients had stage IV disease, and the mean age was 57 years.

TAKEAWAY:

• At a median follow-up of 77 months, the estimated 3-year progression-free survival was 62% in both groups.
• Overall survival at 3 and 6 years was also similar in the two groups — 87% with ASCT vs 86% with radioimmunotherapy at 3 years and 76% with ASCT vs 78% with radioimmunotherapy at 6 years.
• Grade 3 or worse hematologic toxicity occurred in 94% of patients who received ASCT compared with only 46% of those who received radioimmunotherapy; specifically, grade 3 or worse neutropenia occurred in 94% of the ASCT group and 41% of the radioimmunotherapy group.
• More patients receiving ASCT developed secondary cancers — 9 vs 3 receiving radioimmunotherapy (P = .189).

IN PRACTICE:

“Our study indicates that in a modern setting (which includes rituximab in both induction and maintenance) results achieved with ASCT are not superior to those achievable with radioimmunotherapy,” which is “considerably less toxic and demanding,” the research team concluded. “This finding suggests that radioimmunotherapy should be favorably considered” and that the use of ASCT “appears no longer justified, particularly considering its toxicity.”

SOURCE:

The work, led by Marco Ladetto, MD, of the University of Eastern Piedmont, Novara, Italy, was published on November 3, 2023, in Annals of Oncology.

LIMITATIONS:

Investigators aimed for 105 participants in each arm, but the study was closed early owing to slow accrual.

DISCLOSURES:

The work was funded by the Agenzia Italiana del Farmaco and others. Investigators reported numerous ties to pharmaceutical companies, including Roche, maker of rituximab, as well as Amgen and Pfizer, makers of rituximab biosimilars.

M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape. Alex is also an MIT Knight Science Journalism fellow. Email: [email protected]