In June 2025, Bristol Myers Squibb paid BioNTech $1.5 billion upfront — with potential milestones totalling $7.6 billion — for rights to BNT327, an experimental antibody-drug conjugate. The deal was remarkable not just for its size, but for what it revealed about the current state of oncology dealmaking: ADCs have become the most sought-after modality in pharmaceutical M&A, and the premium companies will pay for a promising candidate has reached extraordinary levels.
The BMS-BioNTech deal was not an outlier. In April 2026, Gilead Sciences announced the acquisition of Tubulis, a German biotech developing next-generation ADCs with a novel payload-linker platform. ADC-focused investments have totalled approximately $30 billion over the past decade, with a disproportionate share concentrated in the past two years.
Market Scale
The global antibody-drug conjugate market was valued at approximately $15–16 billion in 2025, depending on the source. Projections for 2035 range from $28 billion to $39 billion, reflecting compound annual growth rates between 7% and 9%. The market is projected to reach $18–19 billion in 2026 alone.
These figures are driven by a combination of newly approved products, expanded indications for existing ADCs, and a clinical pipeline of unprecedented depth. As of early 2026, there are over 300 ADCs in clinical development, with roughly 190 trials evaluating ADC combinations. The pipeline spans virtually every solid tumour type and is expanding into haematological malignancies and, tentatively, non-oncology indications.
Enhertu: The Standard-Bearer
Daiichi Sankyo and AstraZeneca's Enhertu (trastuzumab deruxtecan) remains the commercial and scientific benchmark. Approved across multiple HER2-expressing cancers — including breast, gastric, and non-small cell lung cancer — Enhertu demonstrated that ADCs could achieve meaningful clinical benefit even in patients with low levels of target expression, fundamentally expanding the addressable patient population.
Enhertu's success is rooted in its proprietary DXd payload technology, which enables a higher drug-to-antibody ratio (approximately 8:1 versus the traditional 3–4:1) while maintaining tolerability. The topoisomerase I inhibitor payload also exhibits a bystander effect, killing neighbouring tumour cells that don't express the target antigen — a critical advantage in heterogeneous tumours.
Daiichi Sankyo's pipeline extends the DXd platform to additional targets: datopotamab deruxtecan (TROP2), patritumab deruxtecan (HER3), and ifinatamab deruxtecan (B7-H3). Each represents a potential multi-billion-dollar franchise. The combined commercial potential of the Daiichi Sankyo-AstraZeneca ADC portfolio is projected to exceed $20 billion in peak annual sales.
The Next Generation
The current wave of ADCs is defined by advances in three components: the antibody, the linker, and the payload.
Antibody engineering. Bispecific ADCs — conjugates built on antibodies that bind two different targets — are in early clinical development. The rationale is straightforward: binding two tumour-associated antigens increases selectivity and reduces off-target toxicity. Several bispecific ADC candidates entered Phase I in 2025–2026.
Linker chemistry. The linker connecting the antibody to its cytotoxic payload determines stability in circulation (premature release causes systemic toxicity) and efficient release at the tumour (insufficient release reduces efficacy). Tubulis, the company acquired by Gilead, developed proprietary linker-payload technology designed to improve the therapeutic index. Other companies are developing cleavable linkers that respond specifically to the acidic or enzyme-rich tumour microenvironment.
Novel payloads. Beyond traditional cytotoxic agents (maytansines, auristatins, topoisomerase inhibitors), new payload classes are emerging. Immunostimulatory ADCs carry payloads that activate the immune system at the tumour site rather than killing cells directly. STING agonist-conjugated antibodies, for example, can turn immunologically "cold" tumours "hot." Payload-diversification is arguably the most important frontier in ADC development, as it expands the modality from pure cytotoxicity to immuno-oncology, targeted protein degradation, and even nucleic acid delivery.
The Deal Dynamics
ADC dealmaking has a distinctive pattern. The upfront payments are large because the modality has been de-risked by Enhertu's clinical success, but the platform value — the ability to generate multiple ADCs from a single linker-payload technology — commands additional premium.
Key deals in the 2025–2026 cycle include:
BMS–BioNTech (June 2025): $1.5 billion upfront, up to $7.6 billion total, for BNT327 targeting PD-L1 × VEGF.
Gilead–Tubulis (April 2026): Acquisition of Tubulis and its NaPi2b-targeting ADC TUB-040 for ovarian cancer, plus the broader payload-linker platform.
AbbVie–ImmunoGen: AbbVie's $10.1 billion acquisition of ImmunoGen in 2024 brought Elahere (mirvetuximab soravtansine) for ovarian cancer and the ADC technology platform in-house.
Pfizer–Seagen: Pfizer's $43 billion acquisition of Seagen in 2023 remains the largest ADC-related deal in history, bringing Adcetris, Padcev, and Tukysa under Pfizer's umbrella alongside Seagen's proprietary conjugation technology.
The cumulative signal is unambiguous: large pharma views ADCs as a dominant oncology modality for the next decade and is willing to pay generational premiums for leading platforms.
Manufacturing and Access
ADC manufacturing is substantially more complex than conventional antibody production. The conjugation step — attaching cytotoxic payloads to antibodies — requires specialised facilities, stringent quality control, and handling of potent compounds. This complexity translates to higher costs of goods sold, longer manufacturing timelines, and a structural advantage for companies with established ADC manufacturing capabilities.
The manufacturing bottleneck is real. Several ADC developers have reported supply constraints that limited commercial launch or clinical trial enrolment. Companies like Lonza, Samsung Biologics, and WuXi Biologics have invested heavily in ADC manufacturing capacity, but demand continues to outstrip supply.
For patients, the cost implications are significant. ADCs are typically priced at $10,000–$20,000 per month, reflecting both clinical value and manufacturing complexity. Access in lower-income countries remains limited, and biosimilar pathways for ADCs are more complex than for standard antibodies due to the conjugation step.
What Comes Next
The ADC field is approaching an inflection point where the modality expands beyond oncology. Preclinical programs are exploring ADCs for autoimmune diseases (targeting pathogenic immune cells for destruction), infectious diseases (delivering antibiotics specifically to infected cells), and fibrotic conditions. If these programs reach the clinic, the total addressable market for ADC technology could grow far beyond current oncology-centric projections.
The convergence with AI is also accelerating. Machine learning models are being applied to optimise antibody-target selection, predict linker stability, and design novel payloads with specific pharmacological properties. The same computational approaches that are transforming small-molecule drug discovery are beginning to reshape ADC design — and given the combinatorial complexity of the antibody-linker-payload design space, the potential for AI-driven optimisation may be even greater in conjugates than in traditional drugs.
The gold rush metaphor is apt, but with an important distinction: unlike historical gold rushes, the underlying resource here — the ability to deliver potent therapeutics precisely to diseased cells — has real and growing clinical value. The companies that win will be those that master all three dimensions: the biology of target selection, the chemistry of conjugation, and the manufacturing scale to deliver.