Presentation (CTI)

OBJECTIVES: As high-cost biologics expand, biosimilars can contribute to healthcare sustainability, but uptake depends not only on price and regulatory confidence but also on prescribing decisions and patient acceptance. This study compared biosimilar initiation in new patients with switching among existing biologic users and evaluated physicians’ perceptions and expected impact of proposed policy alternatives to promote biosimilar prescribing.
METHODS: A cross-sectional survey was conducted among 45 Korean physicians with biologic-prescribing experience. Outcomes included current biosimilar share, baseline initiation rate, and baseline switching rate. Fisher’s exact tests and Firth penalized logistic regression explored associated factors. Physicians estimated future percentage-point changes under nine options. Paired t-tests compared expected changes between initiation and switching; two-sample t-tests compared lower- and higher-baseline physicians within each context.
RESULTS: Baseline use was higher for initiation than switching (55.6% vs 24.7%; p<0.0001). Firth logistic regression suggested context-specific patterns: current share and initiation were related to clinical experience and specialty, whereas switching was related to confidence in biosimilar equivalence and regulatory review. For all nine policy options, expected increases were greater for switching than initiation. Notable switching-initiation differences were for biosimilar-first prescribing for new patients (+10.36%p), linkage to healthcare quality assessment indicators (+9.53%p), originator-biosimilar price-gap expansion (+9.16%p), prescribing incentives (+8.42%p), and patient out-of-pocket cost reduction (+7.60%p). Within initiation, lower-baseline physicians showed greater responsiveness to out-of-pocket cost reduction than higher-baseline physicians (23.82%p vs 12.29%p; p=0.0089). Within switching, lower-baseline physicians showed greater responsiveness to quality assessment linkage (33.33%p vs 16.25%p; p=0.0349).
CONCLUSIONS: Biosimilar initiation and switching showed distinct drivers and policy responsiveness. Switching remained limited despite favorable initiation and confidence, suggesting positive perceptions alone may not translate into switching among existing users. Demand-side measures that reduce patient burden and support prescriber decision-making, including incentives and quality assessment linkage, may be needed alongside supply-side price policies, particularly for lower-uptake physicians.