A phase 2 trial of extended induction epratuzumab and rituximab for previously untreated follicular lymphoma: CALGB 50701.
BACKGROUND
Rituximab combined with chemotherapy has improved the survival of previously untreated patients with follicular lymphoma (FL). Nevertheless, many patients neither want nor can tolerate chemotherapy, leading to interest in biological approaches. Epratuzumab is a humanized anti-CD22 monoclonal antibody with efficacy in relapsed FL. Because both rituximab and epratuzumab have single-agent activity in FL, the antibody combination was evaluated as initial treatment of patients with FL.


METHODS
Fifty-nine untreated patients with FL received epratuzumab 360 mg/m2 with rituximab 375 mg/m2 weekly for 4 induction doses. This combination was continued as extended induction in weeks 12, 20, 28, and 36. Response assessed by computed tomography was correlated with clinical risk factors, [18F]fluorodeoxyglucose positron emission tomography findings at week 3, Fcγ polymorphisms, immunohistochemical markers, and statin use.


RESULTS
Therapy was well-tolerated, with toxicities similar to expected with rituximab monotherapy. Fifty-two (88.2%) evaluable patients responded, including 25 complete responses (42.4%) and 27 partial responses (45.8%). At 3 years follow-up, 60% of patients remain in remission. Follicular Lymphoma International Prognostic Index (FLIPI) risk strongly predicted progression-free survival (P = .022).


CONCLUSIONS
The high response rate and prolonged time to progression observed with this antibody combination are comparable to those observed after standard chemoimmunotherapies and further support the development of biologic, nonchemotherapeutic approaches for these patients.
Division of Hematology-Oncology, University of Vermont Medical Center, Burlington, Vermont.
Barbara W
BW
Grant
Sin-Ho
SH
Jung
Jeffrey L
JL
Johnson
Lale
L
Kostakoglu
Eric
E
Hsi
John C
JC
Byrd
Jeffrey
J
Jones
John P
JP
Leonard
S Eric
SE
Martin
Bruce D
BD
Cheson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage* / Q000009:adverse effects; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage* / Q000009:adverse effects; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000009:adverse effects / Q000379:methods*; D008224:Lymphoma, Follicular / Q000378:metabolism / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012074:Remission Induction; D000069283:Rituximab; D016896:Treatment Outcome
D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; C448700:epratuzumab; D000069283:Rituximab
FLIPI score; epratuzumab; follicular lymphoma; monoclonal antibody; rituximab