Abagovomab

Cytoreductive surgery and chemotherapy continue to be the mainstay of ovarian cancer treatment. However, as mortality from advanced ovarian cancer remains very high, novel therapies are required to be integrated into existing treatment regimens. Immunotherapy represents an alternative and rational therapeutic approach for ovarian cancer based on a body of evidence supporting a protective role of the immune system against these cancers, and on the clinical success of immunotherapy in other malignancies. Whether or not immunotherapy will have a role in the future management of ovarian cancer is too early to tell, but research in this field is active. This review will discuss recent clinical developments of selected immunotherapies for ovarian cancer which fulfil the following criteria: (i) they are antibody-based, (ii) target a distinct immunological pathway, and (iii) have reached the clinical trial stage. Specifically, the focus is on Catumaxomab (anti-EpCAM×anti-CD3), Abagovomab, Oregovomab (anti-CA125), Daclizumab (anti-CD25), Ipilimumab (anti-CTLA-4), and MXD-1105 (anti-PD-L1). Catumaxomab has reached phase III clinical trials and exhibits promise with reports, showing that it can cause a significant and sustained reduction in ascites. Phase I-III clinical trials continue to be conducted on the other antibodies, some of which have had encouraging reports. We will also provide our perspective on the future of immunotherapy for ovarian cancer, and how it may be best employed in treatment regimens.

To determine whether abagovomab maintenance therapy prolongs recurrence-free (RFS) and overall survival (OS) in patients with ovarian cancer in first clinical remission.

Patients with International Federation of Gynecology and Obstetrics stage III to IV ovarian cancer in complete clinical remission after primary surgery and platinum- and taxane-based chemotherapy were randomly assigned at a ratio of 2:1 in a phase III, double-blind, placebo-controlled, multicenter study. Abagovomab 2 mg or placebo was administered as 1-mL suspension once every 2 weeks for 6 weeks (induction phase) and then once every 4 weeks (maintenance phase) until recurrence or up to 21 months after random assignment of the last patient. The primary end point was RFS; secondary end points were OS and immunologic response.

Characteristics of the 888 patients included: mean age, 56.3 years; Eastern Cooperative Oncology Group performance status, ≤ 1 in > 99% of patients; serous papillary subtype, 81.5%; stage III, 85.9%; and cancer antigen 125 ≤ 35U/mL after third cycle, 80.9%. Mean exposure to study treatment (± standard deviation) was 449.7 ± 333.08 days. Hazard ratio (HR) of RFS for the treatment group using tumor size categorization (≤ 1 cm, > 1 cm) was 1.099 (95% CI, 0.919 to 1.315; P = .301). HR of OS using tumor size categorization (≤ 1 cm, > 1 cm) was 1.150 (95% CI, 0.872 to 1.518; P = .322). The most frequently reported type of adverse event was an injection site reaction in 445 patients (50.2%), followed by injection site erythema and fatigue in 227 (25.6%) and 212 patients (23.9%), respectively. By the final visit, median anti–anti-idiotypic antibody level was 493,000.0 ng/mL, indicating a robust response.

Abagovomab administered as repeated monthly injections is safe and induces a measurable immune response. Administration as maintenance therapy for patients with ovarian cancer in first remission does not prolong RFS or OS.