Trio of biosimilars have good showing

Biosimilars for three widely used oncology drugs showed efficacy and safety in lung cancer and breast cancer similar to those of the reference products, according to findings reported at the 2018 annual meeting of the American Society of Clinical Oncology in Chicago.

Oncology biosimilars for bevacizumab (Avastin), trastuzumab (Herceptin), and filgrastim (Neupogen and others) have yielded positive results in various patient populations and clinical settings, investigators reported at the annual ASCO meeting. The findings advance the promise of new agents that have no clinically meaningful differences in efficacy and safety when compared with their reference drugs but have substantially lower cost.

“Biosimilars are here,” said Michael A Thompson, MD, PhD, of Aurora Health Care in Milwaukee, Wisconsin, “[although] issues remain, including clinical decision support and pathway adoption, naming differences across the world, competition and lower prices versus the illusion of a free market, and adoption to decrease costs and increase value to our patients.” Dr Thompson was commenting during an invited discussion at the meeting. He is the medical director of the Early Phase Cancer Research Program and the Oncology Precision Medicine Program at Aurora Health (also see Commentary at end of article).

Bevacizumab biosimilar

The REFLECTIONS trial (NCT02364999) was a multinational, first-line, randomized, controlled trial among 719 patients with advanced nonsquamous non–small-cell lung cancer (NSCLC). Patients were randomized to paclitaxel and carboplatin chemotherapy plus either bevacizumab (sourced from the European Union) or the candidate bevacizumab biosimilar PF-06439535 on a double-blind basis, followed by monotherapy with the same assigned agent.

The overall response rate by week 19, confirmed by week 25 – the trial’s primary endpoint – was 45.3% with the biosimilar and 44.6% with bevacizumab, reported lead author Mark A Socinski, MD, executive medical director of the Florida Hospital Cancer Institute in Orlando. The confidence interval (CI) for the risk difference fell within the equivalence margins set by European Union regulators (-13% and +13% for the 95% CI). And the confidence interval for the risk ratio fell within the equivalence margins set by the US Food and Drug Administration (0.73 and 1.37 for the 90% CI) and Japanese regulators (0.729 and 1.371 for the 95% CI).

Median progression-free survival (PFS) was 9.0 months with the biosimilar and 7.7 months with bevacizumab (hazard ratio [HR], 0.974; P = .814), and corresponding 1-year rates were 30.8% and 29.3%, respectively, Dr Socinski reported. Median overall survival was 18.4 months and 17.8 months (HR, 1.001; P = .991), and corresponding 1-year rates were 66.4% and 68.8%.

Rates of grade 3 or higher hypertension, cardiac disorders, and bleeding did not differ significantly with the 2 agents. Patients also had similar rates of grade 3 or higher serious adverse events (AEs) and of fatal (grade 5) serious AEs with the biosimilar and bevacizumab (5.3% and 5.9%, respectively).

“Similarity between PF-06439535 and bevacizumab-EU was demonstrated for the primary efficacy endpoint of overall response rate. ... There were no clinically meaningful differences in safety profile shown in this trial, and similar pharmacokinetic and immunogenicity results were seen across treatment groups,” Dr Socinski summarized. “These results confirm the similarity demonstrated in earlier analytical, nonclinical, and clinical studies of PF-06439535 with bevacizumab-EU.”