ADC Patents: Global Geographical Trends

China’s dominance of the antibody drug conjugate (ADC) market is unlikely to be challenged anytime soon, with the gap between China and other ADC developers only set to get bigger, according to patent publishing data from Beacon.

By the end of 2025 the number of published ADC patents in China is forecast to hit almost 3,000, a 10% increase on last year’s record patent publications.

While China is set to remain at the top of the global ADC market, the US, which led the ADC race until 2023, will lose its second-place spot to Japan if current full-year forecasts play out.

Japan’s forecast 36% jump in full-year patent publications to 2,609, will push the US down to third place. The US, which is witnessing a distinct slowing in patent publishing, is forecast to end the year with 2,222 published patents only a 3% increase on 2024 figures.

Japan’s move up the rankings comes as the whole market for published ADC patents is expected to grow. Total published patents are forecast to hit 21,448 in 2025 (Figure 1), a 12% rise on 2024 numbers, taking the compound annual growth rate for the whole market  to 13.6% since 2015.

Figure 1: Global Drug Conjugate Patent Publication and Grants

Global ADC patent trends from 2015–2025. The graph shows annual counts of granted and published ADC patents, highlighting strong year-on-year growth. Dashed bars indicate 2025 forecasts, with published patents projected to surpass 20,000 and granted patents continuing their steady upward trajectory.

The decade plus rise in ADC patent publications speaks to both the clinical and commercial success of ADCs. Last year, AstraZeneca and Daiichi Sankyo’s Enhertu bought in revenues of $3.75bn, while Roche’s Kadcyla reported full year 2024 sales of $1.99bn.

The sharp acceleration of global patent publications from 2019 coincided with FDA approvals of Enhurtu and other ADCs like Padcev, Trodelvy, and Polivy. Their market authorisation showed that ADC technology could be profitable, triggering a race among competitors to replicate their success by filing patents for “me better drugs”.

More recently the expansion in therapy areas from late-stage blood cancers to solid tumours has increased the potential market size. And technological shifts from second to third generation ADCs, including new payloads, linker technology and site-specific conjugation are also driving the growth in patentable features.

While published patents have grown strongly, granted patents have, however, experienced more modest growth. This is partly due to scrutiny of published patents, resulting in failure, but because with the growth of ADCs comes more complexity and the risk of IP infringement. Last year, Daiichi Sankyo and Pfizer closed their long-running ADC patent arbitration over Enhurtu, with Pfizer – which acquired Seagen – paying Daiichi $47m in costs.

Examining patent publications is a useful predictive tool. Because the time between patent publication and the approval of a drug can take anywhere between five and 15-years, patent filings can offer a valuable glimpse into the future strategy of pharma companies ahead of public disclosure.

So, this year’s growth in the number of patents across the board, indicate that fears that the ADC market might have reached saturation point could be premature.

Again, some of the factors helping with demand is the wave of next generation ADCs including, dual payload ADCs, bispecific ADCs and AOCs.

Wider industry factors, including big pharma’s demand for new assets to fill pipelines as patent expiries loom for some of their biggest blockbusters, could also continue to drive ADC patent publications.

One place big pharma is looking to for new products to restock pipelines is China.

China’s rise in the ADC space has been phenomenal, from lagging both the US and Japan 10 years ago, the country now dominates the space (Figure 2), accounting for most licensing activity and 42% of the global ADC pipeline according to UBS.

China’s growth has been down to several factors including the country embracing an ‘innovation-for-export’ mindset, positioning itself as the world’s ADC factory. Chinese companies are aggressively patenting fully realised ADC candidates with the explicit goal of licensing them to offshore pharma companies. Contributing to the success of this strategy is:

• A favourable regulatory environment: Regulatory changes, such as the Marketing Authorization Holder (MAH) system, that decoupled research from manufacturing has speeded-up development of innovative drugs. While fast-tracking clinical trial application reviews have streamlined approval pathways. Patent publishing was also given a boost in 2021 with the introduction of the Pharmaceutical Patent Term Extension, which compensated biopharma companies for time lost during the regulatory review and approval process for new drugs.
• A large domestic pipeline with an emphasis on innovation: From their origins of optimizing existing technology to make ‘fast follower’ ADCs, Chinese drug developers are increasingly focusing on cutting-edge technologies, including site-specific conjugation techniques and advanced linker technologies. Early home-grown success in the form of RemeGen’s Aidixi, which was approved in 2021 for certain HER2-positive cancers, has also spurred other ADC manufacturers to replicate their success.
• The power of AI: China is currently the world leader in Generative AI patents for drug discovery. Companies are using AI to predict the best ADC structures, allowing them to generate and patent new drug candidates faster than their global rivals.
• Strategic global partnerships: China’s technological advancement and tighter patent protection has seen rising confidence among international partners in licensing Chinese biopharmaceutical assets. Recent large licensing deals include Roche’s $80m upfront deal for ex-China rights to Hansoh Pharma’s experimental CDH17 ADC, HS-20110. Other Chinese deals have been to get next generation ADCs, including Radiance Pharma licensing Novatim’s first in class bispecific nano ADC.
• The rise of the NewCos: Another notable trend driving patent publication in China is venture backed startups launching biotechs around compounds sourced from Chinese laboratories. This ‘NewCo’ model allows Chinese companies to get upfront funding for their assets, while offshore companies can acquire reasonably priced innovation and avoid Chinese foreign-direct-investment hurdles.

All of these factors have fuelled the rise in patent publications in China – and signs of easing of tensions in US-China trade relations could further propel growth in ADC patents.

Figure 2: ADC Patent Publications by Geography

Published ADC patent applications by region, 2015–2025. The graph shows the rapid rise of ADC patent publications across major geographies, with China extending its lead and Japan forecast to overtake the US by 2025. Europe and South Korea also show steady growth, with dotted lines indicating 2025 projections.

Unlike China, the growth in Japanese ADC patent publications has not been driven by an aggressive out licensing model, but Japan’s platform technologies. Daiichi Sankyo’s DXd platform has been described as the ‘gold standard’ due in part to the success of Enheru and the size of its ADC pipeline. Beacon patent data currently shows Daiichi Sankyo as the top ADC patent assignee globally.

Others in the field, Astellas, Rakuten Medical and Takeda also have ADC platform technology, which has helped drive up patent publications in the country and allowed Japan to overtake the US in number of published patents.

Growth in published patents among smaller companies is also being aided by the Japanese governments’ strategic efforts to replicate Daiichi’s blockbuster success.

The Japanese Agency for Medical Research and Development’s ¥350bn ($2.3bn) Double Match Up Grant scheme doubles the investment biotech startups receive from venture capitalist. One of the conditions of the grant is that the startup must have filed a patent application for their product. This has resulted in a rise in patent filings as companies seek to take advantage of the generous scheme.

The rise of both China and Japan is coming at the expense of the US, whose patent publications appear to be plateauing. The US is only set to record a 3% increase in patent publications between 2024 and full year 2025 forecasts.

The US is losing out due to the sheer volume and speed of Chinese R&D in the ADC space, as well as its ability to develop ADCs at a significantly low cost than most geographies. Large China-based contract manufacturing organisations like Wuxi AppTec have also made it cheaper and more efficient to manufacture in China.

While the US is still the most commercially influential ADC market thanks to products like Adcetris and big pharma consolidation (e.g. Pfizer’s acquisition of Seagen), this shift in the global ADC order has seen major US companies increasingly turn to China to license assets rather than using in-house development.

US companies are also prepared to bet big on Chinese ADCs. In 2023 BMS signed one of the biggest licensing deals for a Chinese ADC asset, paying $800m up front for Biokin’s bispecific ADC izalontamab, as part of deal worth up to $8.4bn.

Although the US might be falling behind in patent publishing, it can be argued that competition from Chinese ADCs is forcing US companies to be more innovative in their own research to counter the threat from China.

There have also been position shifts at the smaller end of the global ADC market. From being neck-and-neck in ADC patent publications in 2024, Europe is set to leapfrog South Korea by the end of the year, with a forecast 1,337 published patents against 1,101 for Korea.

Much of Europe’s patent growth is coming from its powerhouse big pharma groups including AstraZeneca, Roche and Novartis who are heavily investing in ADCs.

But ADC innovation clusters in Switzerland and Germany are also fuelling patent publication, with organizations like the Paul Scherrer Institute and ETH Zurich spinning out ADC companies.

Despite the switch in positions South Korea continues to punch above its patent publishing weight given the size of the country. Much of the growth in patent publications is due to Korea’s focus on licensing out its platform technologies. Licensing out technology to multiple partners often means companies file extensive patents to protect every possible configuration of their technology.

Recent technology licensing examples include AbTis’ third generation AbClick linker technology, which selectively links a drug to a specific site on an antibody without modifying the antibody itself. While Alteogen, which has already secured a licensing deal with Daiichi Sankyo, has filed multiple patents for its subcutaneous formulations of ADCs.

With patent publication numbers moving up globally, led by a seemingly unassailable China, the data suggest that biopharma companies are continuing to bet on reaping future financial rewards with ADC development.

And while regions like the US are experiencing slowing growth, for now fears of a slowdown might look overblown. The need for big pharma to fill pipelines, as well as advances in technology, should maintain growth. As will the demand for increasingly effective ADCs to meet current unmet medical needs.

The data in this article was taken from our Beacon Patent database. Learn more about Beacon patents today!