It has been a long, slow road to the recent frenzy in antibody drug conjugate (ADC) activity. After the first publication of an experimental ADC design 60 years ago, it took 20 years for clinical trials to begin and 40 years for the first regulatory approval. That first approval was fraught with disappointment, however, as limited clinical benefit and safety concerns arising during the post-marketing period resulted in a withdrawal.
In order to bring safe and efficacious ADCs to market, scientists needed to overcome tough challenges inherent each of the individual components — the cytotoxic payload (drug), monoclonal antibody (mAb) and chemical linker — as well as that of making them work in combination. Subsequent technological breakthroughs have given researchers a greater understanding of the mechanism of action (MoA) of ADC constituent parts and enabled companies to move forward with innovative treatments.
From pioneering startups to well-resourced large pharmas, a slew of companies is now pursuing breakthrough ADCs with the aim of treating underserved, often intractable cancers. The potential of these therapies to deliver on their promise is gaining attention among big pharmas, which have spent record-breaking amounts to gain access to assets, platforms and entire companies, as described in our recent analysis of pharma dealmaking. Last year’s largest M&A deal, by far, was Pfizer Inc’s $43 billion acquisition of Seagen Inc, which was finalized in December 2023.
Given the hive of activity in this space, it can be extremely challenging to stay abreast of the different approaches, targets and companies, often working at very early stages, as well as the larger ecosystem of investors, partners and research centers supporting their work. To better understand the scientific status quo and identify some promising innovators, Clarivate analysts reviewed data on deal valuations, clinical trials and market approvals in the space to identify seven ADC Companies to Watch, including:
- Adcendo ApS, a company based in Denmark whose lead program targets the uPARAP receptor, which is overexpressed by several mesenchymal cancers, including soft tissue sarcoma, bone sarcoma, gastrointestinal stromal tumors and mesothelioma;
- Araris Biotech AG, a Zurich, Switzerland-based company developing ADCs carrying dual or triple payloads with different MoAs to overcome cancer resistance and heterogeneity;
- GO Therapeutics, a Cambridge, Massachusetts company using a platform-based approach to developing antibody-based therapies against clean glycoprotein cancer targets;
- Heidelberg Pharma AG, headquartered in Ladenburg, Germany, whose ATACs, or ADCs developed using its proprietary ADC payload technology (ATAC® technology), for cancer therapy have amanitin-based compounds as the payload;
- Pheon Therapeutics, based in both London and Boston and developing ADC constructs using both novel and clinically validated mAbs in combination with payloads from its proprietary platform or off-the-shelf linker-payloads;
- Tallac Therapeutics Inc, a company based in Burlingame, California, whose ADC technology uses novel oligonucleotide payloads to create antibody-oligonucleotide conjugates (AOCs) that extend the therapeutic mechanism beyond cytotoxic agents;
- and Tubulis, headquartered in Planegg-Martinsried, Germany, near Munich and developing novel proprietary technologies, including the Tub-tag® and P5 conjugation platforms, that deliver a diverse range of targeting molecules and innovative payloads against solid tumors.
The ADC therapeutics marketplace is expanding rapidly along a number of axes, including:
- A sharp increase in both deal value and volume over the past five years, according to Clarivate data, as pharmas scramble to partner with or acquire ADC companies;
- A shift to later-phase clinical development in oncology, with growing evidence also being generated for indications outside of oncology such as eye, kidney, liver, gastrointestinal and infectious diseases;
- Positive movement within the regulatory environment, with nine of the 13 approved ADCs in the major markets approved within the last five years.
For more insights into this exciting field of therapeutics and a deeper look at the seven companies we’re keeping an eye on, download the report, ADC Companies to Watch.
