Radioimmunotherapy as Front-Line Treatment for Follicular Lymphoma

New research suggests that frontline radioimmunotherapy would benefit patients with follicular lymphoma.

United Kingdom researchers recruited 74 patients with a median age of 61 (ranging from 28 to 80 years of age) who required initial therapy.

Among these research subjects:

• 78 percent had stage III-IV disease
• 32 percent intermediate disease
• 44 percent high-risk disease (according to FL International Prognostic Index).

Treatment consisted of two doses of 90Y-IT (11.1 MBq/kg, also known as Zevalin) administered 8 to 12 weeks apart. Patients with more than 20 percent lymphoma infiltration of bone marrow received one infusion per week for four consecutive weeks of rituximab (375 mg/m2) and proceeded to fractionated radioimmunotherapy only if a repeat bone marrow biopsy demonstrated clearing of lymphoma to less than 20 percent involvement.

The primary end point was end of treatment response of the intention-to-treat population. Secondary objectives were safety and progression-free survival.

Results encouraging

The initial overall response rate was 94.4 percent (68 of 72 patients) with combined complete response (CR/CRu) of 58.3 percent(42 of 72 patients).

Nine patients subsequently improved response, making an ORR of 95.8 percent (69 of 72 patients) and CR/CRu of 69.4 percent (50 of 72 patients).

At a median follow-up of 3.1 years, estimated three-year PFS is 58 percent, treatment-free survival is 66 percent, and overall survival is 95 percent.

However, the median PFS is 40.2 months, and 30 patients have experienced disease progression and 24 have required further treatment.

Side effects were extremely low compared to other studies involving combination chemotherapy.

"This was the first study to look at giving two fractions of radioimmunotherapy as an initial treatment in follicular lymphoma," said Tim Illidge, MRCP, FRCR, FRCPath, Ph.D., of the University of Manchester in the United Kingdom. "We wanted to assess its safety and effectiveness in a group of high-risk patients who conventionally have done less well."

While encouraged by many of the outcomes, Illidge said further studies are needed "in larger numbers of patients to fully compare this treatment to the standard treatment of six to eight cycles of chemotherapy."

The findings appeared in the Journal of Clinical Oncology.

Source: JCO