Can Biocon’s Kirsty become the Semglee of rapid-acting insulin in the US market?

Biocon Biologics Limited, the biosimilars-focused subsidiary of Biocon Limited (BSE: 532523; NSE: BIOCON), is looking to replicate its earlier U.S. success story with Semglee (insulin glargine-yfgn) through the launch of Kirsty (Insulin Aspart-xjhz). The U.S. Food and Drug Administration (FDA) granted approval on July 15, 2025, making Kirsty the first and only interchangeable rapid-acting insulin aspart biosimilar in the country. The approval marks Biocon Biologics’ second major milestone in the U.S. diabetes care market and comes at a time when pricing reforms and payer-led cost pressures are reshaping insulin procurement strategies.

How does Kirsty’s market entry compare with Semglee’s PBM coverage milestones and pricing strategies in the United States?

Semglee’s performance in the U.S. between 2021 and 2024 provides a useful benchmark for gauging Kirsty’s potential. Semglee became the first interchangeable insulin glargine approved in the U.S. and gained traction by securing pharmacy benefit manager (PBM) contracts with Express Scripts, CVS Caremark, and OptumRx within months of launch. This early inclusion on major formularies enabled automatic substitution for Sanofi’s Lantus and contributed to a significant shift in basal insulin prescription patterns. By mid-2023, industry data estimated Semglee’s market share at nearly 20% in the U.S. basal insulin segment, demonstrating that an aggressive contracting strategy and interchangeability designation could meaningfully disrupt an entrenched brand.

Kirsty enters the market with a similar strategic advantage. Interchangeability allows pharmacists to substitute it directly for NovoLog, bypassing prescriber intervention, which has traditionally been a key hurdle for biosimilar adoption. Analysts believe Biocon Biologics will likely employ a comparable PBM-driven pricing strategy to secure early formulary access. With the U.S. rapid-acting insulin aspart market estimated at $1.9 billion in 2024, capturing even 10–15% of the market within two years could translate into a strong revenue stream for the Indian biosimilars manufacturer.

Unlike Semglee, which initially faced skepticism from some prescribers, Kirsty could benefit from greater physician familiarity with interchangeable insulins today. The success of Semglee helped establish confidence in biosimilar insulins’ safety and efficacy, potentially shortening the adoption curve for Kirsty. Additionally, Kirsty’s dual formats—a single-patient-use prefilled pen for subcutaneous administration and a multiple-dose vial for subcutaneous and intravenous use—are aligned with U.S. market preferences, further enhancing its competitive edge.

The timing of Kirsty’s entry also coincides with heightened scrutiny of insulin pricing. Under the Inflation Reduction Act’s insulin cost caps, payers and PBMs are under pressure to adopt lower-cost alternatives without compromising care quality. Analysts argue that Biocon Biologics’ proven track record in offering competitive discounts while maintaining production scale will be critical in winning PBM contracts quickly. If major formulary inclusions occur within the next six to nine months, as they did for Semglee, Kirsty could achieve substantial penetration before rival biosimilar insulin aspart products enter the market.

Will Kirsty’s success help Biocon Biologics consolidate its leadership in global insulin biosimilars?

Kirsty’s success could solidify Biocon Biologics’ reputation as a dominant player in affordable insulin biosimilars, building on its existing leadership in recombinant human insulin and insulin glargine, where it supplies over 9.2 billion doses annually. Success in the U.S. rapid-acting insulin segment would extend its credibility beyond basal insulins and showcase its ability to compete with global leaders such as Novo Nordisk in high-value markets.

However, analysts caution that execution will remain the key determinant of success. Securing long-term PBM contracts, managing competitive pricing pressure from Novo Nordisk, and addressing prescriber inertia for rapid-acting insulins will remain major challenges. The U.S. insulin market is politically sensitive, and margin pressures are expected as PBMs aggressively negotiate discounts to maximize cost savings.

Looking ahead, institutional investors see Kirsty’s adoption as a bellwether for Biocon Biologics’ broader biosimilar ambitions. A strong U.S. performance would validate its “lab-to-market” integrated biosimilar strategy and strengthen its negotiating leverage in other therapeutic categories such as oncology and immunology, where higher-margin products are in the pipeline. If Kirsty’s trajectory mirrors or exceeds Semglee’s growth curve, Biocon Biologics could emerge as the first non-Western biosimilar manufacturer to command a meaningful share of the U.S. insulin market.