Biosimilars Month in Review: August 2024

The biosimilars month in review highlights the new data on biosimilars demonstrating their therapeutic equivalence to reference drugs for the treatment of pulmonary disease and rheumatic diseases. New research and announcements also emphasize the need to improve their access for patients.

New Therapeutic Equivalence Data

This month, new data were released supporting therapeutic equivalence of biosimilars for etanercept for treating moderate-to-severe rheumatoid arthritis (RA), teriparitide for treating osteoporosis in post-menopausal women, and omalizumab for treating severe allergic asthma.

Etanercept Biosimilar Demonstrates Bioequivalence in Phase 3 Study

Among a cohort of patients with moderate to severe RA, an etanercept biosimilar showed bioequivalence to the reference drug regarding safety, efficacy, and immunogenicity, according to findings from a phase 3 clinical randomized trial.

No significant difference across treatment arms were observed (P = .16) and no significant differences in adverse reactions or adverse events were reported, regardless of severity. Antibody development was observed in 5.1% (n = 4) of patients at visit 6, 5.0% (n = 4) at visit 9, and 3.8% (n = 3) at visit 11. Results were similar in the reference drug cohort, with 6.4% (n = 5) developing antibodies at visit 6, 6.5% (n = 5) at visit 9, and 4.1% (n = 3) at visit 11. These differences were not significant (P > .99).

Teriparatide Biosimilar Demonstrates Therapeutic Equivalence in Postmenopausal Women With Osteoporosis

RGB-10, a teriparatide biosimilar, recently demonstrated therapeutic equivalence to reference teriparatide in treating osteoporosis in postmenopausal women at very high risk of fracture in a retrospective study of a real-world experience data.

The investigators did not find any significant differences between the treatment groups on any measured parameters at any timepoints. At all timepoints, both treatment groups experienced significant improvements in measured parameters from baseline, although these were not all statistically significant and statistical significance sometimes differed between treatment groups. They noted that the major limitations of the study are its nature as a retrospective analysis, its single center source, and its relatively small number of patients included.

Omalizumab Biosimilar Equivalent to Reference Drug in Children With Severe Allergic Asthma
P043, an omalizumab biosimilar, was found to be equivalent to reference omalizumab in reducing exacerbations and managing asthma, with no significant differences in efficacy and safety parameters.

The P043 cohort had a 0.150 exacerbation rate (95% CI, 0.079-0.220) and the omalizumab cohort had a 0.190 exacerbation rate (95% CI, 0.079-0.220; per-protocol). The least squares mean differences of predicted Forced Expiratory Volume in the First second (FEV1) were -2.51% (95% CI, -7.17-2.15; P = .29) pre-bronchodilator use and -3.87% (95% CI: -8.79-1.04; P = .12) post-bronchodilator use. In the P043 group, mean Asthma Control Test (ACT) scores at screening were 10.62 (standard deviation [SD], 2.93) and 20.93 (SD, 4.26) at last visit. In the omalizumab group, mean ACT scores were 11.09 (SD, 2.75) at screening and 20.46 (SD, 5.11) at the last visit.

Improved Access for Biosimilars Needed

A paper published in August highlighted the slow uptake of biosimilars, looking specifically at infliximab, and emphasized the need to improve uptake and access. Making some progress on that front, a Humira biosimilar was added last month to Costco's member prescription program.

More Biosimilars, New Policy Levers Needed to Speed Biosimilar Adoption

New research into uptake and insurance coverage of infliximab biosimilars has suggested that 1 or 2 biosimilars may not generate enough competition to speed adoption rates and policy levers are needed to speed up Medicare adoption.

biosimilar uptake rose slowly with the first and second biosimilar releases, with small average annual increases in Medicare (3.2%), Medicaid (5.2%), and private insurance (1.8%) uptake from 2016 to June 2020. After the third biosimilar was released in July 2020, Medicaid (13%) and private insurance (16.4%) uptake increased greatly but Medicare uptake (5.6%) remained low. Medicare uptake continued to lag and by September 2022 was 24%, while Medicaid uptake was 43.8% and private insurance uptake was 38.5%.

Humira Biosimilar Added to Costco Member Prescription Program
Adalimumab-aaty (Celltrion USA), a Humira biosimilar, has been added to the Costco member prescription program, allowing eligible members and their dependents to obtain the drug at a substantial discount.

"We are pleased to partner with Costco, the largest warehouse club and third-largest retailer in America," Francine Galante, Vice President, Market Access, Celltrion USA, said in a statement. "We are committed to increasing patient choice through access to biosimilars. The inclusion of adalimumab-aaty to the Costco Member Prescription Program will expand patients' treatment options and help reduce healthcare costs."