Xcellon Biologics, a Maryland CRDMO specializing in bioconjugates and complex biologics, has signed a definitive agreement to acquire the GMP biologics manufacturing facility built by NextCure, Inc. in Beltsville. The deal gives Xcellon its first cGMP capacity, completes the company’s transition from a development-stage CDMO into an end-to-end CRDMO, and puts a commissioned domestic bioconjugation suite behind what its new chief executive describes as a bid to build one of the nation’s premier CRDMOs for bioconjugates and complex biologics. Financial terms were not disclosed. GMP operations are expected to begin in December 2026.
The capacity is specific and near-term. The 40,000-square-foot facility includes two 1,000-liter single-use bioreactors, a dedicated bioconjugation suite, high-throughput process development capabilities built around advanced robotics, and analytical and characterization laboratories — a configuration built for clinical-scale supply of complex biologics rather than benchtop work. Xcellon has operated roughly 7,000 square feet of lab space in Rockville since launching in January 2025, so the acquisition represents close to a sevenfold expansion of footprint and extends the company into Prince George’s County, a jurisdiction carrying considerably less biomanufacturing inventory than Montgomery.
It also moves up a clock. When BioBuzz reported in July on Xcellon’s position in the ADC market, the company’s GMP capability was slated to come online in late 2026 or early Q1 2027, supported in part by a TEDCO Equitech Growth Fund infrastructure grant. Acquiring a facility that is already commissioned rather than finishing one lands at the near edge of that window, with a conjugation suite that exists today.
What that capacity enables is the integration Xcellon has been describing since it launched: antibody development, bioconjugation, analytical sciences, and GMP manufacturing inside a single organization, with a client able to move from cell line through clinical supply without changing vendors.
Xcellon named co-founder Abhishake Chhibber as Chief Executive Officer alongside the acquisition. “This acquisition represents far more than the expansion of our manufacturing capabilities,” Chhibber said in a statement. “By integrating antibody development, bioconjugation development, analytical sciences, and GMP manufacturing within a single organization, we are creating a platform that enables innovators to move seamlessly from discovery through clinical supply.”
Chhibber positioned that platform against a larger question — where next-generation biologics get manufactured, and by whom. “America has long been the global engine of biotechnology innovation,” he said. “Our mission is to strengthen the development and manufacturing infrastructure that enables innovators to move seamlessly from discovery through clinical supply. By doing so, we aim to help ensure the United States remains the world’s leader in next-generation biologics and advanced biomanufacturing.”
The market gives that ambition room. Pharma spent the first half of 2026 acquiring ADC capability at scale — Gilead agreed to pay up to $5 billion for Tubulis, Novartis paid more than $1 billion for Myricx Bio, Johnson & Johnson acquired Firefly Bio, and UCB spent $2.2 billion on Candid Therapeutics — and every one of those programs eventually requires a manufacturing slot. Clinical-grade conjugation demands specialized containment and high-potency handling, and carries an analytical burden covering drug-to-antibody ratio distribution, aggregation, payload stability, and linker integrity with no close equivalent in standard biologics. Dual-payload and site-specific constructs raise the difficulty further. North America accounted for an estimated 42 to 45 percent of the global ADC contract manufacturing market in 2025, and industry executives increasingly describe domestic conjugation capacity as a constrained resource as on-shoring pressure pushes demand higher.
Chhibber has helped shape Xcellon’s strategy since its founding and brings close to two decades across biotech and pharma spanning corporate strategy, business development, operations, finance, and company formation. He is also a co-founder of Linden Lake Labs, the Rockville venture studio that backs Xcellon and that saw a seed-to-exit outcome in under 18 months this spring, when Eli Lilly acquired portfolio company CrossBridge Bio for up to $300 million.
Co-founder Yuk Chun Chiu continues as Chief Operating Officer. Chiu, whose career runs through Human Genome Sciences, Amgen, Lonza, Sanofi, Bayer, and AstraZeneca, was a founding member of Wheeler Bio in Oklahoma City before returning to Maryland, and told BioBuzz in 2025 that reconnecting with Chhibber and Linden Lake Labs’ Thomas Haag started the conversation about building a CDMO specialized for ADCs and T-cell engagers. “By reducing handoffs between service providers and maintaining scientific continuity throughout development, we help clients advance complex biologics more efficiently,” Chiu said of the acquisition.
The facility became available as its builder exits the business. NextCure announced a definitive merger agreement with San Francisco-based Avere Therapeutics on July 14, an all-stock transaction paired with a $320 million private placement led by Fairmount and Hansoh Pharmaceutical. If the deal closes as expected in the second half of the year, the combined company will operate as Avere Therapeutics under the Nasdaq ticker AVRX, led by Avere CEO Andrew Cheng, and will pursue a once-weekly oral IL-23 receptor antagonist rather than NextCure’s antibody-drug conjugate programs in oncology. Securities filings tied to the transaction describe a restructuring beginning in July expected to reduce a substantial majority of NextCure’s workforce during the quarter ending September 30, with roughly $1.9 million in one-time cash charges, primarily severance. BioBuzz noted the wind-down of the company’s Maryland operations in its July 31 Regional Roundup.
Neither company has said what happens to the staff who ran the Beltsville site — operators who know how to run 1,000-liter single-use trains, maintain a GMP quality system, and characterize a complex biologic under high-potency handling conditions. Those roles sit inside the restructuring, and Xcellon needs that expertise in that building by December. The announcement does not address whether any employees transfer with the facility, which is the difference between acquiring a plant and acquiring a working one.
Xcellon has spent the past 18 months building demand for capacity it did not yet have, announcing ADC collaborations with Invenra and IntoCell, launching the Xcellerate program for early-stage developers who need CMC work before they can fund it, and releasing XSpec™, an online configurator for scoping conjugation chemistry, linker architecture, payload class, and target DAR. In December, the supply side arrives to meet it — 40,000 square feet of U.S. bioconjugation infrastructure returned to service, and a stated ambition that now has a plant attached to it.
Xcellon Biologics, a wholly owned subsidiary of Linden Lake Labs., is a U.S.-based, partner-centric Contract Research, Development and Manufacturing Organization (CRDMO) focused on bioconjugates and complex biologics. Xcellon’s capabilities span cell line development, antibody development and manufacturing, bioconjugation development and manufacturing, process development, analytical characterization, GMP manufacturing, and clinical supply.
Media contact: Yuk Chiu, Chief Operating Officer, Xcellon Biologics — [email protected]
