Seagen Licenses ADC Asset From a Chinese Player to Disrupt HER2 Market

On August 9th, US company Seagen announced an exclusive worldwide license and co-development agreement with China-based RemeGen for a novel HER2-targeted antibody-drug conjugate (ADC) therapy disitamab vedotin.

Under the agreement, Seagen will pay $200 million upfront for global development and commercialization outside Asia, except Japan and Singapore. In addition, RemeGen will be eligible for a total milestone payment of up to $2.4 billion on attaining specific development, regulation, and commercialization milestones across multiple indications and products.

Growing Field of Antibody Drug Conjugates

ADCs have become increasingly significant in the oncology landscape. However, since 2019, only six out of eleven ADCs marketed worldwide for hematologic and solid tumor malignancies have obtained regulatory approvals. As most ADCs consists of a cytotoxic agent binding to a monoclonal antibody (mAb) that targets a specific tumor-associated antigen, this combination is generally too toxic to be systematically administered.

Even so, pharma companies are jostling their way for a slice in the field. Although there is still a long way to go, Seagen is confident and optimistic toward the future collaboration with RemeGen.

“This collaboration leverages Seagen’s world-class expertise and knowledge of ADC development, manufacturing, and commercialization to maximize the potential of disitamab vedotin. It also complements our existing franchises and our deep and diverse portfolio of innovative anti-cancer therapies for patients in need,” said Clay Siegall, President and CEO of Seagen.

“The addition of disitamab vedotin as a late-stage asset with multiple development opportunities aligns strategically with our plans to continue expanding our global footprint and deliver meaningful therapies to patients around the world,” he added.

Disitamab Vedotin

Disitamab vedotin is a combination of Seagen’s drug-linker technology and RemeGen’s novel HER2 antibody to fight against several solid tumor types such as urothelial, gastric, and breast cancers across a spectrum of HER2 expression levels.

By virtue of its high affinity and an increased internalization rate, disitamab vedotin demonstrated promising antitumor activity in clinical trials, as compared to Genentech’s Herceptin (trastuzumab). After acing a pivotal Phase 2 trial where 24.4% of patients with HER2 overexpressing gastric cancer showed beneficial outcomes, disitamab vedotin bagged regulatory approvals both in the US and China within two years.

In 2020, it earned the FDA’s Breakthrough Therapy designation for the second-line treatment of patients with HER2-expressing, locally advanced, or metastatic urothelial cancer (mUC) who have previously been treated with platinum-containing chemotherapy.

In the same year, RemeGen announced FDA clearance of an IND application for a Phase 2 clinical trial in mUC. This year China’s National Medical Products Administration also accepted an NDA for the same indication.

Intense Competition

Disitamab vedotin is a direct rival to Roche’s Kadcyla and AstraZeneca and Daiichi Sankyo’s Enhertu, the ADC drugs approved for HER2 driven cancer indications. Enhertu is expected to hit $5.7 billion in sales by 2030, while Kadcyla is estimated to earn more than $2 billion this year.

Besides disitamab vedotin will be facing Seagen’s own tisotumab vedotin, an ADC that awaits the FDA decision for cervical cancer treatment, and Merck & Co.’s ladiratuzumab vedotin presently in development for triple-negative breast cancer.

Author

Judy Ya-Hsuan Lin

Success is the ability to go from one failure to another with no loss of enthusiasm.