Can Antibodies Target Cancer Too? Why the New Anticancer Technology 'ADC' Is Gaining Attention

HER2-targeting ADC 'Enhertu' jointly developed by Daiichi Sankyo and AstraZeneca

[Asia Economy Reporter Lee Chun-hee] Interest in antibody-drug conjugate (ADC) pharmaceuticals is rising. At the American Society of Clinical Oncology (ASCO) in June, Daiichi Sankyo and AstraZeneca announced clinical results showing that the anti-HER2 ADC 'Enhertu,' jointly developed by the two companies, demonstrated significant efficacy even in HER2-negative breast cancer patients, who account for 80% of breast cancer cases. This announcement was met with a standing ovation at the event, sparking excitement as a new type of drug that could potentially conquer cancer.

As the name suggests, ADCs are drugs that conjugate antibodies and drugs. They are pharmaceuticals that connect antibodies and cytotoxic drugs (payloads) via linkers. Recently, ADCs have shown excellent efficacy, leading to many receiving accelerated approval, and their clinical success rate averages 10.8%, which is comparable to the 12.1% success rate of antibody drugs.

Currently, worldwide, starting with Seagen's lymphoma treatment 'Adcetris' launched in 2011, 11 ADC drugs have been released. Earlier, in 2000, Mylotarg received FDA approval but was soon withdrawn due to liver toxicity issues and was reapproved in 2017 after reducing the dosage. Additionally, it is known that 90 ADC therapeutic agents are currently undergoing clinical trials.

Among these, Adcetris and 'Kadcyla' have grown into blockbuster drugs, generating sales of $1.938 billion (approximately 2.5328 trillion KRW) and $2.169 billion (approximately 2.8347 trillion KRW) respectively as of last year. The overall ADC pharmaceutical market is expected to grow from $6.2 billion (about 8 trillion KRW) last year to $26 billion (about 34 trillion KRW) by 2028. Enhertu, which has not yet been widely distributed in the market, is also projected to achieve sales of $7.741 billion by 2028 once it is globally launched.

Sigen's lymphoma treatment ADC drug 'Adcetris'

This situation is also reflected in direct market movements. It is reported that the U.S. company Merck (MSD) is pursuing the acquisition of Seagen, raising market expectations. Starting with the first ADC new drug, the lymphoma treatment 'Adcetris,' Seagen has successfully commercialized three ADC therapies including the urothelial cancer treatment 'Padcev' and the breast cancer treatment 'Tukysa,' making it the leading biotech company in ADC development. Given Seagen's current market capitalization of $32 billion, this could become a mega big deal.

Domestically, companies such as LegoChem Biosciences, Alteogen, and Pinobio are also developing ADC technologies. LegoChem Biosciences plans to present the Phase 1a clinical trial results of the HER2-targeting ADC 'FS-1502,' licensed to China's Fosun Pharma, at the European Society for Medical Oncology (ESMO) conference in September. Holding ADC linker and payload technologies, LegoChem has signed a total of nine ADC platform and candidate substance technology transfer contracts besides FS-1502.

Alteogen has developed 'NexMab ADC' technology, which modifies the antibody's Fc terminal used as a carrier through recombinant gene technology and conjugates the linker only at this site. Using this technology, they have completed Phase 1 clinical trials in Korea for the breast cancer treatment 'ALT-P7.'

However, ADCs also carry significant risks related to toxicity. Mylotarg, considered the first ADC, experienced withdrawal of approval due to toxicity issues. Since ADCs induce cancer cell death through cytotoxic efficacy, if the payload detaches before reaching the target cells, side effects related to blood toxicity may occur. Known side effects include neutropenia, thrombocytopenia, anemia, pulmonary toxicity, and serosal hemorrhage.

Pinobio is continuing efforts to overcome these issues through new approaches. They have developed 'PinoADC' technology that uses camptothecin-class drugs as payloads to suppress the expression of cancer cell anti-apoptotic proteins even at low concentrations. Through this, they are independently developing the Trop-2-targeting ADC anticancer drug 'PBX-001.'

This content was produced with the assistance of AI translation services.