A Randomized, Double-Blind, Efficacy and Safety Study of PF-05280586 (a Rituximab Biosimilar) Compared with Rituximab Reference Product (MabThera®) in Subjects with Previously Untreated CD20-Positive, Low-Tumor-Burden Follicular Lymphoma (LTB-FL).

BACKGROUND: Biosimilars are highly similar to the licensed biologic ("reference product"), with no clinically meaningful differences in safety, purity, or potency between the two products. OBJECTIVE: This comparative 52-week clinical study evaluated the efficacy, safety, immunogenicity, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-05280586 (Ruxience™ [a rituximab biosimilar]) versus rituximab reference product sourced from the EU (MabThera®; rituximab-EU). PATIENTS AND METHODS: Subjects with CD20-positive, low-tumor-burden follicular lymphoma (LTB-FL) and an Eastern Cooperative Oncology Group performance status 0-1 were randomized (1:1) to PF-05280586 or rituximab-EU (375 mg/m2 intravenously [once weekly for 4 weeks at days 1, 8, 15, and 22]), stratified using the Follicular Lymphoma International Prognostic Index 2 classification. The primary endpoint was overall response rate (ORR) at week 26 (percentage of subjects achieving complete response [CR] or partial response [PR]). Therapeutic equivalence was concluded if the two-sided 95% confidence interval (CI) for the difference in ORR between groups was within the prespecified margin (± 16%). Secondary endpoints included progression-free survival (PFS), CR rate, safety, immunogenicity, PK, and PD. RESULTS: A total of 394 subjects were randomized: PF-05280586 (n = 196) or rituximab-EU (n = 198). ORR at week 26 was 75.5% (PF-05280586) versus 70.7% (rituximab-EU), for a difference of 4.66%; 95% CI (- 4.16 to 13.47), which was entirely within the prespecified equivalence margin. Rates of CR were 29.3% (PF-05280586) versus 31.0% (rituximab-EU). Estimated 1-year PFS rates were 78.2% (95% CI 70.2-84.2) and 83.0% (95% CI 75.0-88.6) for PF-05280586 and rituximab-EU, respectively. Safety, immunogenicity, and mean serum concentrations were similar between groups. CONCLUSIONS: The efficacy, safety, immunogenicity, PK, and PD of PF-05280586 and rituximab-EU were similar up to week 52 in subjects with previously untreated CD20-positive LTB-FL. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02213263 and EudraCT (2014-000132-41).

Will bevacizumab biosimilars impact the value of systemic therapy in gynecologic cancers?

OBJECTIVE: Bevacizumab is an important component in the treatment of various cancers, and despite guidelines recommending its use in both ovarian and cervical cancer, patient access to bevacizumab and other angiogenesis inhibitors is limited. Biosimilars are large, structurally complex molecules that are intended to be highly similar to, and treat the same condition(s) as, an existing licensed or approved (reference) biologic, with no clinically meaningful differences in purity, potency and safety. This article summarizes the role of bevacizumab in the treatment paradigm of ovarian and cervical cancer. We also discuss the potential role of biosimilars to bevacizumab, which may offer more affordable options in the future treatment of gynecologic cancers. METHODS: Literature searches of PubMed and ClinicalTrials.gov databases were conducted. Regulatory and individual pharmaceutical company web pages were also reviewed. Search terms included "biosimilar" and "bevacizumab," and these were used to identify information regarding biosimilar development, reporting results of biosimilar studies or biosimilars in development. RESULTS: At present, four bevacizumab biosimilar candidates are undergoing comparative clinical assessment, with the potential to increase access and offer efficiencies across healthcare systems. CONCLUSIONS: It is anticipated that biologics such as bevacizumab will continue to play a key role in the treatment of an array of gynecologic cancers. Biosimilars to bevacizumab are currently in development and have the potential to increase access to medicines in a variety of settings, including gynecologic cancers.