Improved biosimilar adoption rates drive healthcare cost savings in SG

In Singapore’s public healthcare institutions, value-driven healthcare strategies have contributed to the high adoption rates of biosimilars, leading to lower treatment costs and, subsequently, significant healthcare cost savings, as shown in a retrospective cross-sectional study.

“Biosimilars are biological therapeutic products with proven similarities in physicochemical characteristics, biological activity, safety, and efficacy compared with their reference biological products (RBPs),” the researchers noted.

“Singapore has reached the 5-year mark since the subsidy listing of the first monoclonal antibody (mAb) biosimilar infliximab … Following this listing, the utilization of biosimilars increased steeply, and spending on mAbs significantly declined within a year,” they said.

The study used aggregated drug utilization data from all public healthcare institutions in SG. Five mAbs with biosimilars listed for Ministry of Health subsidy between 2018 and 2022 – infliximab, adalimumab, trastuzumab, rituximab, and bevacizumab – were included. [Pharmacoecon Open 2024;8:679-688]

Within a year of listing, the adoption rate of most biosimilars reached >95 percent. Drugs with more than one approved biosimilar brand at the time of subsidy listing reported marked price reductions of over 80 percent.

Since its listing in 2018, infliximab use has doubled and achieved a steady state in 2022. “Considering infliximab biosimilar was the first mAb biosimilar to be subsidized, a slower adoption rate was expected compared with the other biosimilars,” the researchers explained.

Adalimumab, rituximab, and bevacizumab biosimilars accounted for over 95 percent of their respective market shares within a year of subsidy implementation.

For trastuzumab, total utilization increased post-subsidy listing but dwindled in 2022. “This could be related to the increasing use of new drugs, such as trastuzumab deruxtecan in 2022, which resulted in a drop in total trastuzumab utilization,” they explained. Another factor that could have driven the decline in trastuzumab use is the emergence of new formulations (eg, subcutaneous formulation or trastuzumab in combination with other agents).

Cost savings

Before the five biosimilars entered the SG market, RBPs were only listed for selected registered indications and specific cohorts, given their high cost and budget impact. “Placing these biosimilars on the Standard Drug List and removing any coverage restriction led to improved patient access to treatment,” the researchers shared, noting that the estimated number of patients using these drugs jumped from 1,800 in 2018 to over 4,000 by 2022.

Despite this increase, overall spending dropped from ~$57 million in 2018 to nearly $25 million in 2022. “Based on the difference between simulated spending assuming no biosimilar entry and actual spending for the five drugs, the SG public healthcare system cost savings were estimated to be $74 million in 2022. This further translates to cumulative cost savings of ~$136 million over 5 years,” they explained.

“The sharp drop in spending resulted from the significantly lower price of biosimilars except for trastuzumab, where the lower utilization in 2022 could have partially contributed to the drop in spending,” said the researchers.

A key initiative to keep costs down and sustainable

The researchers noted that increasing healthcare expenditure is a global concern, and keeping the healthcare system sustainable remains a challenge. “Considering the high and growing expenditure on biologics, strategies have been implemented to drive the use of biosimilars.”

Given the emerging real-world data on the efficacy and safety of biosimilars, and as more patented mAbs go off-patent, adopting biosimilars may continue to be one of the key initiatives to keep healthcare costs affordable and sustainable in SG, they said.

“The high adoption rate of biosimilars hinges on disinvestment from non-cost-effective RBPs, ie, delisting of RBPs from subsidy listing and encouraging the use of lower-cost alternatives and the listing of a second biosimilar brand,” the investigators noted.

“Continued monitoring of utilization of biosimilars post-subsidy listing and sharing early signals of suboptimal utilization with relevant stakeholders could further enhance biosimilar uptake,” they said.