Formosa Pharmaceuticals Targets First ADC Biosimilar Launch in US and Europe with TSY-110
核心洞察
Formosa Pharmaceuticals (搜索) and EirGenix (搜索) have submitted a European Clinical Trial Application for TSY-110 (搜索), a Kadcyla (trastuzumab emtansine) biosimilar, with clinical trials expected to begin this year.
Regulatory consultations with the FDA and EMA indicate PK and bioequivalence comparability are the primary review criteria, and Phase 3 efficacy trials may be waived.
Licensing discussions with large global pharmaceutical companies are in an advanced stage, targeting completion for US and European markets by 2026 and launch by 2029.
Formosa Pharmaceuticals (搜索) is positioning itself to become the first company to launch an antibody-drug conjugate (ADC) biosimilar in the United States and Europe, with its Kadcyla biosimilar TSY-110 (搜索) advancing toward clinical trials and a licensing deal that could be the largest transaction in the company's history.
The TSY-110 (搜索) program, co-developed with EirGenix (搜索), submitted its European Clinical Trial Application (CTA) in late August and has completed regulatory consultations with both the US FDA and the European EMA. Chief Business and Strategy Officer Wei Jingcheng disclosed that clinical trials will be led jointly by Formosa Pharmaceuticals (搜索) and EirGenix, with trials expected to start this year.
Regulatory Pathway and Potential Phase 3 Waiver
The most consequential regulatory development centers on whether Phase 3 efficacy trials can be avoided. According to Wei, while regulators "didn't give a definitive answer," they clearly indicated that the primary review focus would be on PK (pharmacokinetic) and BE (bioequivalence) comparability, and that Phase 3 efficacy trials "have a chance of being waived."
When analysts pressed on this ambiguity, Wei conveyed cautious optimism: "EirGenix (搜索) has successful experience in this area, and the team has carefully confirmed the regulatory requirements." He emphasized that in communications with the FDA and EMA, the joint team with EirGenix had asked "very, very clearly" about "what to compare and what to look at."
Licensing Strategy and Market Opportunity
Licensing progress appears to be the most advanced element of the TSY-110 (搜索) program. Wei disclosed that the primary negotiation counterparties are "very, very large global pharmaceutical companies," with licensing territories covering the US, Europe, and other major markets, and that "one party is in a relatively advanced stage of negotiation."
The company's objectives are explicit: complete licensing for major US and European markets by 2026, launch in the US and Europe by 2029, and secure the position of "the first ADC biosimilar to launch in the US and Europe." The originator drug Kadcyla posted global sales of approximately $2.5 billion in 2025 and has entered the late stage of its product lifecycle, creating a maturing window for biosimilar entry.
Wei noted that after the main deal concludes, "there's actually still a strong opportunity to achieve a multi-point licensing arrangement," with multiple smaller licensing deals running in parallel for regions not covered by major partners, including the Middle East, Southeast Asia, and Latin America.
Tripartite Division of Labor
A structural advantage lies in the three-way collaboration underpinning the program. EirGenix (搜索)'s Trastuzumab antibody is already commercially manufactured at scale in Taiwan and the EU, Formosa Laboratories provides large-scale CDMO production capability for ADCs, and Formosa Pharmaceuticals (搜索) leads development and external licensing. Wei emphasized: "From CMC development to clinical trials and external licensing, the collaboration and advancement have been extremely close."
TSY-310 and the ADC Pipeline
Beyond TSY-110 (搜索), the company is advancing TSY-310 (搜索), a dual-target ADC that has demonstrated efficacy in both lung adenocarcinoma (搜索) and squamous lung cancer (搜索). In a triple-negative breast cancer (搜索) model, TSY-310's anti-tumor efficacy "outperformed Merck (搜索)'s VLS-101, which is in clinical development," with no toxicity-related weight loss observed in animals during treatment, corroborating its tolerability.
On licensing strategy, the company has chosen a deliberately conservative value-maximization path, planning to complete Phase 2 before pursuing licensing. Wei explained two core considerations: "the closer to market stage, the greater the licensing value," and CMC stability and data package completeness directly enhance licensing value. However, he left room for flexibility: "Early-stage licensing is possible. Of course, collaboration is also possible—it could be with large pharmaceutical companies or additional co-development partners."
For the 2027 IND filing, the Phase I trial will primarily explore safety and starting dose, enrolling patients with solid tumors without restricting to specific indications. The team expects to discover "unexpected" indications in the basket trial.
BYQLOVI Supply Recovery
On the commercial front, BYQLOVI (搜索)—the company's already-approved ophthalmic product—has resumed production after contract manufacturing disruptions. Wei was candid about the situation: "In terms of supply, I can only say yes, but not much," noting that "relative to the orders we've received, the delivery ratio so far is still very low. So we're in a situation where customers are chasing us."
The root cause lay with the backend contract manufacturer. Starting in early 2026, orders from US and Canadian customers had been steadily coming in, but production issues stalled both production and delivery. Production has now resumed, with "capacity running at full throttle" to clear the backlog, while a second production facility is being prepared to meet global demand.
The financial impact was severe: Formosa Pharmaceuticals (搜索) posted zero revenue for four consecutive months from April through July 2026. The last month with recorded revenue was March, at NT$40 million (approximately $1.3 million), representing a year-over-year surge of over 32-fold. Q2 revenue was zero, bringing first-half total revenue to just NT$50 million (approximately $1.6 million).
The Taiwan market is poised to become the first commercialization battleground, with BYQLOVI (搜索) launching on a self-pay basis in late September through hospital-affiliated and in-hospital pharmacies. Clinician feedback has centered on two selling points: twice-daily dosing (versus four to six times daily for conventional ophthalmic steroids) and homogeneous dispersion without sedimentation, which improves patient compliance.
APNT Platform Expansion
The company is also positioning its APNT nanoparticle formulation technology as a long-term value engine. In collaboration with the Singapore Eye Research Institute (SERI), the APNT formulation increased drug exposure in the ocular aqueous humor by 5 to 10 times. In posterior segment delivery validation, the APNT suspension formulation achieved drug concentration improvements of 40% (at 0.2% concentration) to 80% (at 0.5% concentration) compared to the DMSO solution formulation originally used by the partner.
Wei acknowledged that collaborations with national-level research institutions like SERI "may not generate large amounts initially," with substantive returns materializing only when co-development projects advance to the licensing stage.