Biosimilars in Oncology: From Development to Clinical Practice

Biologics play an integral role in the treatment of cancer not only for their therapeutic effects and ability to improve outcomes, but also as supportive care agents. Biologics are more complex to manufacture and take longer to bring to market. Because biologics are considerably more costly than small-molecule drugs, their use has placed an increasing economic demand on healthcare systems worldwide. Biosimilars are designed to be highly similar to existing branded biologics, but because biologics cannot be exactly copied, biosimilars should not be referred to as generic, exact versions of the innovator biologic. Biosimilars have the potential to increase access and provide lower cost options for cancer care as patent protection for some of the most widely used biologics begins to expire. Regulatory requirements for biosimilars are evolving, as are global harmonization and/or standardization strategies that can facilitate their robust clinical development. This review highlights critical factors involved with the integration of biosimilars into oncology treatment paradigms and practices. Clinicians will likely seek out practice guidelines and position statements from established scientific societies to help evaluate key information regarding biosimilars, such as efficacy, safety, comparability, and interchangeability with the reference biologic. Automatic substitution, nomenclature, extrapolation of clinical data from one indication to another, as well as parameters for ongoing pharmacovigilance are evolving considerations. Education of physicians and other healthcare providers, payers, and patients about biosimilars may facilitate informed decision making, promote acceptance of biosimilars into clinical practice, increase accessibility, and expedite associated health and economic benefits

Capivasertib in Hormone Receptor-Positive Advanced Breast Cancer.

Background: AKT pathway activation is implicated in endocrine-therapy resistance. Data on the efficacy and safety of the AKT inhibitor capivasertib, as an addition to fulvestrant therapy, in patients with hormone receptor-positive advanced breast cancer are limited. Methods: In a phase 3, randomized, double-blind trial, we enrolled eligible pre-, peri-, and postmenopausal women and men with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer who had had a relapse or disease progression during or after treatment with an aromatase inhibitor, with or without previous cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor therapy. Patients were randomly assigned in a 1:1 ratio to receive capivasertib plus fulvestrant or placebo plus fulvestrant. The dual primary end point was investigator-assessed progression-free survival assessed both in the overall population and among patients with AKT pathway-altered (PIK3CA, AKT1, or PTEN) tumors. Safety was assessed. Results: Overall, 708 patients underwent randomization; 289 patients (40.8%) had AKT pathway alterations, and 489 (69.1%) had received a CDK4/6 inhibitor previously for advanced breast cancer. In the overall population, the median progression-free survival was 7.2 months in the capivasertib-fulvestrant group, as compared with 3.6 months in the placebo-fulvestrant group (hazard ratio for progression or death, 0.60; 95% confidence interval [CI], 0.51 to 0.71; P<0.001). In the AKT pathway-altered population, the median progression-free survival was 7.3 months in the capivasertib-fulvestrant group, as compared with 3.1 months in the placebo-fulvestrant group (hazard ratio, 0.50; 95% CI, 0.38 to 0.65; P<0.001). The most frequent adverse events of grade 3 or higher in patients receiving capivasertib-fulvestrant were rash (in 12.1% of patients, vs. in 0.3% of those receiving placebo-fulvestrant) and diarrhea (in 9.3% vs. 0.3%). Adverse events leading to discontinuation were reported in 13.0% of the patients receiving capivasertib and in 2.3% of those receiving placebo. Conclusions: Capivasertib-fulvestrant therapy resulted in significantly longer progression-free survival than treatment with fulvestrant alone among patients with hormone receptor-positive advanced breast cancer whose disease had progressed during or after previous aromatase inhibitor therapy with or without a CDK4/6 inhibitor. (Funded by AstraZeneca and the National Cancer Institute; CAPItello-291 ClinicalTrials.gov number, NCT04305496.)