Abstract P1-14-01: Final analysis of overall survival (OS) for the epoetin alfa (EPO) phase 3 study, EPO-ANE-3010, of EPO plus standard supportive care (SOC) versus SOC in anemic patients with metastatic breast cancer (MBC) receiving standard chemotherapy

Background: In the interim analysis of study EPO-ANE-3010, for the primary endpoint of progression-free survival (PFS), the non-inferiority objective in ruling out a 15% increased risk in progressive death (PD) or death per investigator-determined PD was not achieved (JCO 34:1197-1207, 2016). PFS, based on independent review committee (IRC)-determined PD, however, met the non-inferiority criteria. At the interim analysis, OS with 1,337 deaths was reported; we now report the final analysis at 1,653 deaths and the updated PFS.

Methods: This multinational (19 countries and 132 participating sites), phase 3, randomized, open-label noninferiority study included anemic (≤11.0 g/dL hemoglobin) women receiving first- or second-line standard chemotherapy for MBC (Eastern Cooperative Oncology Group performance status of 0 or 1). Subjects were randomized (1:1) to receive either standard SOC for treatment of anemia plus EPO (40,000 IU subcutaneous) weekly up to 4 weeks after the last dose of cytotoxic chemotherapy, or SOC alone. The primary endpoint was PFS (using Cox's regression model). Secondary endpoints included OS, time to tumor progression (TPP), overall response rate (ORR) and safety assessments.

Results: A total of 2,098 subjects were enrolled (EPO plus SOC: n=1,050; SOC alone: n=1048). Demographic and baseline characteristics were well-balanced across the groups; median age was 52 years, most were white (67.5%) or Asian (30.5%) and median BMI was 26.0 kg/m2. Primary efficacy analysis (based on investigator-determined PD) showed a median PFS of 7.4 months for both groups (hazard ratio [HR], 1.094; 95% CI: 0.996, 1.201);upper bound exceeded prespecified noninferiority margin of 1.15. A 9% increased risk for PD/death in the EPO plus SOC group was observed and did not statistically rule out a 15% increased risk. Median PFS per IRC-determined PD was 7.6 months in both groups (HR, 1.028; 95% CI: 0.922, 1.146), this met pre-defined non-inferiority margin of 1.15 with a 3% risk increase in PD/death in EPO plus SOC group. At the final analysis for OS, median OS was 17.8 months in the EPO plus SOC group and 18.0 months in the SOC group; HR: 1.073 (95% CI: 0.974, 1.182); median TPP was 7.5 months in both groups (HR, 1.099; 95% CI, 0.998 to 1.210), and ORR was 50% in the EPO plus SOC group and 51% in the SOC group (odds ratio, 0.939; 95% CI, 0.789, 1.117). Red blood cell (RBC) transfusions were 5.8% versus 11.5% (P<0.001), and thrombotic vascular events were 2.8% versus 1.4% (P=0.038), respectively, in EPO plus SOC group and SOC group. The incidence of death due to PD were similar in both groups (EPO plus SOC: 93%; SOC: 91%).

Conclusion:The primary endpoint, PFS based on investigator-determined PD, did not meet noninferiority criteria but for PFS based on IRC-determined PD, noninferiority criteria was met. Overall, this study did not statistically rule-out a 15% increased risk in PD/death. The final analysis did not show statistically different OS in the EPO plus SOC group versus the SOC group. No new safety signals were noted with EPO treatment and the results are consistent with the known safety profile of EPO.

Citation Format: Leyland-Jones B, Bondarenko I, Nemsadze G, Smirnov V, Litvin I, Kokhreidze I, Abshilava L, Janjalia M, Li R, Lakshmaiah KC, Samkharadze B, Tarasova O, Shparyk Y, Polenkov S, Vladimirov V, Han J, Safonov I, Appiani C, Leitz G. Final analysis of overall survival (OS) for the epoetin alfa (EPO) phase 3 study, EPO-ANE-3010, of EPO plus standard supportive care (SOC) versus SOC in anemic patients with metastatic breast cancer (MBC) receiving standard chemotherapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-14-01.

A Randomized, Open-Label, Multicenter, Phase III Study of Epoetin Alfa Versus Best Standard of Care in Anemic Patients With Metastatic Breast Cancer Receiving Standard Chemotherapy

PURPOSE

An open-label, noninferiority study to evaluate the impact of epoetin alfa (EPO) on tumor outcomes when used to treat anemia in patients receiving chemotherapy for metastatic breast cancer.

METHODS

Women with hemoglobin ≤ 11.0 g/dL, receiving first- or second-line chemotherapy for metastatic breast cancer, were randomly assigned to EPO 40,000 IU subcutaneously once a week or best standard of care. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, time to tumor progression, overall response rate, RBC transfusions, and thrombotic vascular events.

RESULTS

In 2,098 patients randomly assigned, median PFS (based on investigator-determined disease progression [PD]) was 7.4 months in both groups (hazard ratio [HR], 1.089; 95% CI, 0.988 to 1.200); upper bound exceeded prespecified noninferiority margin of 1.15. Median PFS per independent review committee-determined PD was 7.6 months in both groups (HR, 1.028; 95% CI, 0.922 to 1.146); upper bound did not exceed prespecified noninferiority margin. Median overall survival at clinical cutoff (1,337 deaths) was 17.2 months in the EPO and 17.4 months in the best standard of care group (HR, 1.057; 95% CI, 0.949 to 1.177), median time to tumor progression was 7.5 months in both groups (HR, 1.094; 95% CI, 0.991 to 1.209), and overall response rate was 50% versus 51% (odds ratio, 0.950; 95% CI, 0.799 to 1.130). RBC transfusions were 5.8% versus 11.4% (P < .001), and thrombotic vascular events were 2.8% versus 1.4% (P = .038), respectively.

CONCLUSION

The primary end point, PFS based on investigator-determined PD, did not meet noninferiority criteria. As a consistency assessment with the primary finding, PFS based on independent review committee-determined PD met noninferiority criteria. Overall, this study did not achieve noninferiority objective in ruling out a 15% increased risk in PD/death. RBC transfusion should be the preferred approach for the management of anemia in this population.