Oregovomab maintenance monoimmunotherapy does not improve outcomes in advanced ovarian cancer.
OBJECTIVE
This phase III study tested the hypothesis that the CA-125-specific murine monoclonal antibody, oregovomab, administered as a monoimmunotherapy after front-line therapy in a selected ovarian cancer population would prolong time to relapse (TTR) and, ultimately, survival.


METHODS
Patients with stage III to IV ovarian cancer with preoperatively elevated CA-125 and objectively defined characteristics were randomly assigned 4 to 12 weeks after front-line carboplatin and paclitaxel chemotherapy to maintenance monoimmunotherapy in a fully blinded protocol. Two mg of oregovomab or placebo was infused over 20 minutes at weeks 0, 4, and 8 and then 12 weeks until recurrence or up to year 5. Patients were evaluated with serial imaging and clinical evaluation for evidence of recurrence at quarterly visits. TTR was the primary end point.


RESULTS
Three hundred seventy-three patients were accrued at more than 60 centers; 251 patients were assigned to oregovomab and 120 patients were assigned to placebo. The treatment arms were well balanced. There were no differences in the clinical outcomes between treatment groups. Median TTR measured from randomization after completion of chemotherapy for the integrated study was 10.3 months (95% CI, 9.7 to 13.0 months) for oregovomab and 12.9 months (95% CI, 10.1 to 17.4 months) for placebo (P = .29, log-rank test). The treatment was well tolerated. Grade 3 to 4 toxicity was reported in 24.6% of patients in the placebo group and 20.1% of patients in the oregovomab group, respectively.


CONCLUSIONS
Although oregovomab has demonstrated bioactivity, the strategy of monoimmunotherapy is not effective as maintenance therapy after front-line treatment of a favorable subset of patients with advanced ovarian cancer. Future studies of this or other tumor-antigen specific immunization strategies should seek ways to further augment induced immunity.
Berek
Jonathan
J
Division of Gynecologic Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA. jberek@stanford.edu
Taylor
Peyton
P
McGuire
William
W
Smith
L Mary
LM
Schultes
Birgit
B
Nicodemus
Christopher F
CF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D000912:Antibodies, Neoplasm / Q000009:adverse effects / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use; D018394:CA-125 Antigen / Q000276:immunology; D016190:Carboplatin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000009:adverse effects / Q000379:methods*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000401:mortality; D017239:Paclitaxel / Q000627:therapeutic use; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D018394:CA-125 Antigen; D016190:Carboplatin; C107428:oregovomab; D017239:Paclitaxel