WuXi XDC to Acquire Dongao Pharma for HK$3.091 Billion, Strengthening Global ADC CDMO Leadership

On the evening of January 14, WuXi XDC, WuXi Biologics, and Tot Biopharm jointly announced that Citibank would acquire all issued shares of Tot Biopharm for and on behalf of the offeror, WuXi XDC.(excluding the shares already owned or agreed to be acquired by the Offeror and parties acting in concert with it), and cancel all outstanding share options.

The acquisition price is HK$4.00 per share in cash. As of the date of this announcement, the total number of issued shares of Tot Biopharm was 772,787,887, with a total market capitalization of approximately HK$3.091 billion. The acquisition carries a significant premium, representing a premium of approximately 99% over the closing price on the last unaffected day (December 22, 2025); a premium of approximately 114.67% over the average closing price for the past 30 trading days; and a premium of approximately 280.79% over the audited net asset value per share as of the end of 2024.

The completion of the transaction is subject to multiple conditions precedent, the most critical of which is that valid acceptances for shares must be received by the deadline such that the offeror holds no less than 60% of the voting rights in Tot Biopharm. To ensure the success of the transaction, major shareholders, including Suncare Pharmaceutical Holdings, Vivo Capital, and Chengwei Evergreen Capital, have signed irrevocable undertakings to accept the offer, with these committed shares accounting for exactly 60% of the issued share capital.

Founded in 2010, Tot Biopharm leverages its one-stop industrialization platform to provide end-to-end CDMO services—from early-stage R&D to commercial manufacturing—for protein-based therapeutics (represented by antibodies), biosimilars, and conjugated drugs (represented by ADCs).

In terms of technology,The company owns BDKcell^®Cell Line Development Platform, GL-DisacLink^®Innovative technology platforms such as site-specific conjugation technology and the BDKLyo™ digital lyophilization platform, along with BioDlink, a one-stop platform covering the entire lifecycle of biologics. The BioDlink one-stop platform encompasses key modules including cell line development, process development, analytical method development, and GMP manufacturing, supporting the development and production of various biologics such as monoclonal antibodies, bispecific/multispecific antibodies, fusion proteins, and ADCs/XDCs. Unlike the traditional fragmented model involving multiple sites and suppliers, BioDlink adopts an integrated model that completes the entire process from Drug Substance (DS) to Drug Product (DP) within the same campus. This approach significantly reduces technology transfer steps, lowers the risk of batch variability and quality fluctuations, and is particularly suitable for drug types requiring high consistency across processes, such as ADCs/XDCs.

In terms of production capacity,Tot Biopharm is located in the Suzhou Industrial Park, covering an area of 50,000 m². It operates four complete international commercial production lines (two for antibodies and two for ADCs), comprising five drug substance workshops (including a non-toxic conjugation drug substance workshop) and four drug product workshops. The annual drug substance capacity for antibodies is 300,000 liters, with an annual drug product capacity of 30 million units. The annual drug substance capacity for ADCs is 960 kg, with an annual drug product capacity of 5.3 million vials. The facility offers significant production flexibility, has successfully fulfilled numerous non-standard orders, features high efficiency in production line changeovers, provides customized services, and supports client on-site participation at key testing milestones.

In terms of compliance,Its quality management system is established based on ICH Q10 and the FDA’s six-system inspection model, adhering to the ALCOA+ principles of data integrity. All production and operational processes strictly comply with the Good Manufacturing Practice (GMP) quality management systems of major global regulatory authorities, including the NMPA, FDA, and EMA, ensuring product quality and compliance. Over the past three years, Tot Biopharm has successfully undergone more than 90 regulatory and GMP audits worldwide, meeting GMP standards in China, the United States, and Europe. The company holds GMP certifications from China and PIC/S member countries, as well as certification from Japan’s PMDA, qualifying it to serve the global market.

Leveraging these advantages, Tot Biopharm has established a leading position in the commercialization of ADC CDMO services, exemplified by its successful enablement of the world’s first commercialized EGFR-targeted ADC project. Classified as a “Breakthrough Therapy,” this project demanded exceptionally high standards from the client regarding supply chain stability, CMC quality systems, technology transfer speed, and scale-up capabilities. According to announcements by the Shanghai Medical Products Administration, this product is the eighth domestically developed Class 1 innovative drug approved for marketing in Shanghai in 2025, and the second biologic product included in the pilot program for segmented manufacturing. Furthermore, this project represents the first globally approved EGFR-targeted ADC drug and the first ADC drug approved in China that was manufactured entirely by a CDMO.

In addition, in recent years, Tot Biopharm has cumulatively delivered over 160 biologic drug projects, covering multiple key regulatory and commercialization stages; two additional commercialized products have also been launched. In 2025, Tot Biopharm ranked among the top 20 large-molecule CDMOs in China, achieved an AA rating in Wind ESG assessments, and its production capacity and technological reserves serve as a significant complement to WuXi XDC.

The announcement stated that, in the short term following the completion of this acquisition, Tot Biopharm has no plans for significant business adjustments or changes to its management and staff, ensuring a smooth business transition. Upon completion of the transaction, Tot Biopharm will remain listed on the Hong Kong Stock Exchange and will become a subsidiary of both WuXi XDC and WuXi Biologics, with its financials consolidated into both entities. WuXi Biologics is the controlling shareholder of WuXi XDC. WuXi XDC will continue to monitor Tot Biopharm’s operations and reserves the right to make changes to the latter’s business and operations. Tot Biopharm resumed trading on January 15, 2026; as of 4:00 p.m. on that day, its share price had surged by 67.6% following the resumption of trading.

The global ADC drug market is experiencing explosive growth, spawning opportunities across the entire industry chain. On the transaction front, based on disclosed deal values, the total global transaction amount for ADCs exceeded $140 billion from 2015 to 2025. On the industrial front, as of the end of December 2025, 21 ADCs had been approved globally, with novel bioconjugate drugs rapidly emerging. On the market front, Frost & Sullivan data shows that the global ADC drug market size was only $7.9 billion in 2022, surged to $14.1 billion in 2024, and is projected to surpass $68.5 billion by 2030, representing a compound annual growth rate (CAGR) of 30.1% from 2024 to 2030.

However, the development of antibody-drug conjugates (ADCs) is not merely a triumph of a single technology; rather, it hinges on three critical components: the antibody, the linker, and the payload. An ideal ADC drug functions like a precision-guided strategic missile: the antibody serves as the navigation system, responsible for identifying and locking onto the target; the payload acts as the warhead, tasked with destroying the target; and the linker functions as a sophisticated safety mechanism, ensuring stability during transit and releasing its potency only at the target site. Consequently, the development and industrialization of ADCs impose exceptionally high demands on technical expertise, manufacturing facilities and equipment, and quality control.

This has spurred the rapid development of CDMOs in the ADC field. Relevant data show that the outsourcing rate for ADC drug development is as high as 70%, significantly higher than the 30%–40% outsourcing rate for biologics overall.

In the ADC CDMO sector, WuXi XDC’s market share has surged from 9.9% in 2022 to 22.2% in the first half of 2025, ranking second globally.To meet the rapidly growing capacity demands of the global ADC industry, WuXi XDC has been actively expanding its production capabilities in recent years, in addition to this transaction. From the perspectives of addressing market demand and ensuring supply chain security, the company previously proposed a “global dual-site manufacturing” strategy. Its Singapore facility was completed in June 2025 and is expected to commence GMP production in the first half of 2026. In September 2025, WuXi XDC also completed a $350 million refinancing to prepare for capacity expansion.

WuXi XDC CEO Li Jincai once stated that for CDMOs, the most critical factors are building robust technology platforms and making adequate forecasts regarding production capacity. “It is extremely difficult to secure large orders without expanding production capacity or lacking the capital to do so. This is a very practical issue, which has gradually become a significant competitive moat.”It is evident that for CDMOs, the strategic choice to overcome capacity bottlenecks directly determines their market influence. However, the timeline for companies to build their own production lines typically spans 3–5 years, making it difficult to match the rapidly growing demand in the field of antibody-drug conjugates (ADCs). Through this acquisition, WuXi XDC can swiftly acquire Tot Biopharm’s mature capabilities in drug R&D, manufacturing, and contract production, thereby expanding and securing additional operational capacity and strengthening its overall production prowess.

Regarding the core objective of this acquisition, WuXi XDC stated that it aims to rapidly acquire Tot Biopharm’s established operational capacity, compliance systems, and business resources in China through external integration, thereby further strengthening its overall production capabilities to meet the rapidly growing commercial demand in the bioconjugate drug industry. Meanwhile, by leveraging Tot Biopharm’s project portfolio and customer base in the ADC field, WuXi XDC can enrich its own project pipeline, expand its customer base, and consolidate its leadership position in the ADC CDMO sector.

We look forward to the strong partnership between WuXi XDC and Tot Biopharm, which will enable resource sharing and complementary advantages in R&D, manufacturing operations, and market expansion. This collaboration will further enhance WuXi XDC’s comprehensive strength in the ADC CDMO sector, positioning it as a leading ADC CDMO provider rooted in China and serving the global market.