ASCO Posters Reflect on Reimbursement Trends, Combination Therapies Involving Biosimilars

Two posters from the American Society of Clinical Oncology Annual Meeting examined Medicare reimbursement trends for both originator and biosimilar biologics,¹ as well as the use of a combination therapy incorporating a pegfilgrastim biosimilar in patients with advanced hepatocellular carcinoma (HCC).²

In the first study, oncology biosimilars effectively drove down health care costs and drug reimbursement rates by breaking the upward price trend of reference agents, with the authors highlighting that more research needs to investigate the impact of rebates, payer policies, 340B programs, and discounts on average sales price (ASP) and Medicare reimbursement.

CMS used ASP as a benchmark for determining Medicare drug reimbursement (MCR) in the US, updating it quarterly. The study examined the trends in ASP and MCR reimbursement rates for 7 reference agents (rituximab, bevacizumab, trastuzumab, pegfilgrastim, filgrastim, infliximab, and epoetin alfa) and their 25 biosimilars over a 2-year period before and 5 years after the launch of the biosimilars.

The study utilized publicly available CMS data to compare the MCR trends of the reference products and their biosimilars. Results showed that, on average, the MCR for all reference agents increased by 9.2% in the 2 years before the launch of biosimilars. However, in the 5 years following the introduction of biosimilars, the MCR for reference agents decreased by 32.7%, while the MCR for biosimilars dropped by 50.3%. Additionally, biosimilar MCR rates declined more rapidly than those of reference agents.

Notably, 76% of biosimilars entered the market with an MCR lower than their reference agents, while 20% had a higher MCR. Subsequent biosimilars for reference agents typically launched with a higher MCR than the first biosimilar. Despite the overall decrease in MCR, reference agents still had rates double those of their corresponding biosimilars in the most recent quarter, except for pegfilgrastim, which experienced an 87% drop in MCR, resulting in a price lower than 5 out of its 6 biosimilars. This is likely due to Amgen, the company behind reference pegfilgrastim, prioritizing sales for its on-body pegfilgrastim device (Neulasta Onpro) over the original reference agent.³

The other study concluded that the combination of SCT-I10A, an anti-PD-1 monoclonal antibody, and SCT510, a bevacizumab biosimilar, offered significant clinical benefits compared with sorafenib and has an acceptable safety profile, supporting its use as a first-line treatment option for advanced HCC.

HCC is a major health issue in China and a leading cause of cancer-related deaths. The preferred initial therapy for advanced HCC involves combining immunotherapy with anti-vascular growth therapy. This study aimed to assess the safety and efficacy of SCT-I10A combined with SCT510 (a bevacizumab biosimilar) compared with sorafenib for first-line treatment of advanced HCC.

During the open-label, multicenter, phase 3 trial (NCT04560894) in China, patients with advanced HCC who had not previously received systemic therapy were enrolled. They were randomized to receive either SCT-I10A (200 mg every 3 weeks) plus SCT510 (15 mg/kg every 3 weeks) or sorafenib (400 mg orally twice daily). The primary end points were overall survival (OS) and progression-free survival.

By the interim analysis cutoff date of November 2, 2023, a total of 346 patients were enrolled and received at least 1 dose of the study drug (n = 230 in the SCT-I10A/SCT510 group; n = 116 in the sorafenib group), with a median follow-up of 19.7 months. The SCT-I10A/SCT510 group showed a significantly longer median OS (22.1 months) compared to the sorafenib group (14.2 months), with a hazard ratio (HR) of 0.60 (95% CI, 0.44-0.81; P = .0008).

Median PFS was also significantly longer in the SCT-I10A/SCT510 group (7.1 months) vs the sorafenib group (2.9 months; HR, 0.50; 95% CI, 0.38-0.65; P < .0001). The objective response rate was higher in the SCT-I10A plus SCT510 group (32.8%) compared to the sorafenib group (4.3%).

Grade 3 or higher treatment-related adverse events (TRAEs) were more common in the SCT-I10A/SCT510 group than in the sorafenib group (42.6% vs 33.6%), with hypertension being the most common grade 3 or higher TRAE (7.8% in the SCT-I10A/SCT510 group vs 4.3% in the sorafenib group). Three drug-related deaths occurred in the SCT510 group due to unknown causes, intracranial hemorrhage, or upper gastrointestinal hemorrhage.

References

1. Albaugh J, Indurlal P. Medicare reimbursement trends of biological agents and their biosimilars. Presented at: ASCO; May 31-June 4, 2024; Chicago, IL. Abstract 11155.

2. Xu J, Zhang Y, Wang G. SCT-I10A combined with a bevacizumab biosimilar (SCT510) versus sorafenib in the first-line treatment of advanced hepatocellular carcinoma: A randomized phase 3 trial. Presented at: ASCO; May 31-June 4, 2024; Chicago, IL. Abstract 4092.

3. Bangia I. Contributor: Drug delivery devices help originator companies retain market share. The Center for Biosimilars®. September 19, 2020. Accessed June 19, 2024. https://www.centerforbiosimilars.com/view/contributor-drug-delivery-devices-help-originator-companies-retain-market-share