Rituximab has been an effective treatment for chemotherapy-refractory low-grade non-Hodgkin’s lymphoma (NHL). The integration of rituximab(Drug information on rituximab) (Rituxan) into standard first-line oral chemotherapy for low-grade NHL was initiated in order to evaluate the response rate and toxicity of this non-cross-resistant combination.
Chemotherapy-naive patients with low-grade non-Hodgkin’s lymphoma requiring treatment were eligible for study. All patients were treated with six cycles of chlorambucil(Drug information on chlorambucil) (Leukeran) at 0.1 mg/kg po days 1-5 and prednisone(Drug information on prednisone) at 100 mg po days 1-5. Cycles were repeated at 28-day intervals. Rituximab at 375 mg/m2 was administered intravenously on days 2, 9, 16, and 23 of the first cycle only. Between June 1999 and May 2000 20 patients were entered.
Patients included 10 males and 10 females, with an age range of 39 to 87 years. Histology was as follows: follicular cell carcinoma (FCC) small cleaved (8), FCC mixed (8), FCC large (2), and FCC unspecified (2). Patients were classified as stage I (2), II (7), III (7), or IV (4). Median time on study is 171 days (range: 55 to 386 days). Response evaluation is done prior to cycle 3 and 1 month following the completion of therapy.
All patients have completed at least two cycles of therapy and are evaluable for response. The overall response rate is 80% (4 complete responses [CR], 12 partial responses [PR], 2 stable disease, 2 inevaluable). One inevaluable patient had non-neutropenic sepsis and death at day 8 of cycle 1, and the other had a severe anaphylactoid reaction to rituximab necessitating discontinuation of therapy. Other grade III toxicities include one deep-vein thrombosis, one septicemia during cycle 6, and one central nervous system (CNS) bleed with normal platelet count.
To date only one objective responder has progressed. Additionally, there was one death on treatment, and 5 patients are alive and off study (1 rituximab reaction, 1 CNS bleed, 3 progressive disease). Fourteen patients are alive and on study (6-month follow-up: 5 CR, 1 PR, 8 too early to assess).
CONCLUSION: Combination biological and chemotherapy in this setting will require long-term follow-up and formal comparison to chemotherapy alone in the treatment of low-grade NHL.