Congress Abstracts 2004

84

SECOND-LINE THERAPY WITH ZEVALIN^® PRODUCES HIGHER RESPONSE RATES AND MORE DURABLE RESPONSES IN PATIENTS WITH B-CELL NHL: IMPLICATIONS FOR NURSING PRACTICE. Kathy Byar, RN, BSN, University of Nebraska, Omaha, NE, and Donna Fernando, RN, RT, MAOM, University of California Los Angeles Lymphoma Program, Los Angeles, CA.

Zevalin^®, a second-generation radioimmunoconjugate, was the first radiolabeled monoclonal antibody approved by the FDA for the treatment of patients with cancer.

Zevalin is indicated for the treatment of patients with relapsed or refractory low-grade, follicular, or transformed B-cell non-Hodgkin lymphoma (NHL), including patients with rituximab-refractory NHL. This analysis was conducted to determine whether the number of prior therapies affects the response to Zevalin in the indicated population.

An integrated analysis of 211 patients in four clinical trials of Zevalin was performed. Results for patients who had received one therapy prior to Zevalin (second-line) were compared to those for patients who had received Y2 therapies (range: 2–9) prior to Zevalin (third-line+).

Sixty-three patients in the four trials received second-line Zevalin, and 148 received third-line+ Zevalin. Patient groups were similar, except for greater bone marrow involvement in second-line patients (57% versus 39%; P = .023) and a trend toward bulkier disease in third-line+ patients. The overall response rate (ORR) was higher in second-line patients than in third-line+ patients (86% versus 72%; P = .051), as was the complete response/complete response, unconfirmed rate (CR/CRu) (49% versus 28%; P = .004). Median time to progression (TTP) (12.6 versus 7.9 months; P = .038) and duration of response (DR) (13.7 versus 8.2 months; P = .163) were significantly longer in second-line patients. In the follicular NHL subgroup (n = 169), ORR was higher in second-line patients (90.6% versus 79.3%; P = .0815); CR/CRu was significantly higher in second-line patients (54.7% versus 30.2%; P = .0035); and median TTP (14.9 versus 9.2 months; P = .038) and DR (14.2 versus 8.2 months; P = .093) were longer in second-line patients. Adverse events in second-line and third-line+ patients were primarily hematologic. Rates of grade 3/4 neutropenia (21.6% versus 19%; P = .54), thrombocytopenia (68.3% versus 65.5%; P = .75), and anemia (12.7% versus 20.9%; P = .18) were similar in both subgroups. Nonhematologic adverse events were primarily grade 1 or 2. Zevalin is more effective when used earlier in the course.

Oncology nurses will be seeing more patients treated with Zevalin after the failure of first-line therapy, and should be familiar with the administration and tolerability profile to educate patients.