‘Oscotec proves competitiveness in targeting tau protein for Alzheimer’s treatment with tech transfer to Sanofi’

Oscotec's recent deal with Sanofi involved preclinical, clinical development, CMC, and business development (BD) working together like one team from the initial stages. This process served as a proving ground, demonstrating the company's new drug development capabilities. The key figures behind this project are, from left, Vice President Kwak Young-shin (Head of Research Institute), Executive Director Shim Hye-seok (Research Planning Team), Lee Sung-sil (Head of Clinical Development Team), CEO Yoon Tae-young, Jeong Dong-sik (Head of CMC Team), and Park Seong-ho (Head of Pharmaceutical Evaluation Team). (Courtesy of Oscotec)

Osotec does not view its recent technology transfer to Sanofi as merely a single-substance transaction, according to company executives.

Preclinical, clinical development, CMC, and business development (BD) worked together like a single team from the initial stages, and the process itself served as a proving ground, demonstrating the company's drug development capabilities.

The progression from co-development to global tech transfer of the Alzheimer’s tau antibody, ADEL-Y01, shows how Oscotec turns “organizational R&D” into results, the executives said.

Central to this project are Oscotec CEO Yoon Tae-young, Vice President Kwak Young-shin (Head of Research Institute), Executive Director Shim Hye-seok (Head of Research Planning Team), Clinical Development Team Leader Lee Seong-sil, CMC Team Leader Jeong Dong-sik, and Pharmaceutical Evaluation Team Leader Park Seong-ho.

To explore these developments in greater depth, Korea Biomedical Review met with Oscotec's key researchers to discuss the significance of this Sanofi technology transfer and the future direction of R&D.

Oscotec transferred the worldwide exclusive development and commercialization rights for ADEL-Y01, a tau-targeted Alzheimer's disease drug candidate jointly researched and developed with ADEL, to Sanofi.

ADEL-Y01 is an antibody therapy candidate that selectively targets “acetylated tau (tau-acK280),” a key pathological factor among tau proteins in Alzheimer's disease. It is designed to recognize and block only pathological tau while minimizing effects on normal tau protein. The company explains that this could fundamentally slow disease progression. Alongside beta-amyloid, the tau-targeting approach has steadily gained attention in academic circles as a next-generation strategy.

KBR: What significance does this Sanofi technology transfer hold for Oscotec's mid- to long-term strategy?

Yoon: I've had a strong interest in the Alzheimer's field since my previous position, but when I joined Oscotec in 2020, the company didn't have many visible pipelines beyond lazertinib. Starting a new program from scratch would take too long, so we saw the need for a “bridge asset” to fill the gap.

Joint development with ADEL was a strategic choice. It would let us move quickly from preclinical to clinical stages, enabling early licensing. The new program was not aligned with our main focus, but we pursued it to achieve rapid results and momentum for our own pipeline. I see this deal as the catalyst that pushed Oscotec to fully pursue R&D.

Kwak: While establishing the “2030 Vision” with executives, we shared the goal of expanding beyond small molecules into other modalities, such as antibodies, and into additional disease areas after 2028. This achievement holds significant meaning as it quickly demonstrated that we are a company capable of developing antibody-based new drugs. I believe it exemplifies how the inherent capabilities developed with lazertinib can be applied across any modality.

KBR: Bringing an antibody compound from the preclinical stage to clinical trials must not have been easy.

Yoon: ADEL managed CMC production, while we used consulting for some tasks. Oscotec’s main expertise was in small molecules, thanks to lazertinib, but we also had experience compiling preclinical toxicity and PK data for the IND package. We directly led the preclinical/IND package development and clinical preparations.

Jeong: Before administering to humans, preparations such as toxicity testing, PK assessments, and documentation are essential. While there are differences in guidance between small molecules and antibodies, we addressed gaps by drawing on our existing IND experience. Since ADEL lacked sufficient nonclinical specialists, Oscotec led preparations to determine the necessary additional tests and toxicity evaluation methods.

KBR: When did business development (BD) activities begin in earnest?

Yoon: We began initial discussions with global pharma companies after establishing robust preclinical efficacy and nonclinical data. Given the risk profile in Alzheimer's, most major companies awaited clinical proof of concept.

However, we consistently provided updates over a period of three to four years. The atmosphere changed late last year when UCB's tau antibody demonstrated potential in clinical trials. The judgment that licensing might be possible without clinical proof of concept began to form about a year ago. Sanofi showed serious interest starting early this year.

KBR: Many tau-targeted Alzheimer's treatments have failed. What makes the compound developed by Oscotec and Adel unique?

Yoon: Recent research commonly concludes that while amyloid beta may be the “trigger,” tau is the direct cause of actual neuronal damage and disease progression. Amyloid is like a match, while tau is the wildfire. The crucial point isn't “targeting tau,” but “which tau to target.” Failed antibodies targeted tau that was not pathologically central.

In contrast, ADEL-Y01 targets acetylated tau (tau-acK280). The key point is that it aims for the “sweet spot” closest to the most pathological and highly infectious tau species. There was experimental data supporting this story, and I believe Sanofi recognized it, which led to the deal.

Lee: When we explained this concept to U.S. clinical researchers, we received positive feedback. Researchers who had participated in past amyloid clinical trials also commented, “We would like to participate in research with this concept.”

KBR: What are the clinical benefits of selectively targeting “acetylated tau”?

Yoon: The antibody is designed not to block just one tau function, but to prevent the spread of tau aggregates—a key factor in disease progression. We need to zero in on the most infectious and pathological tau fragments. Acetylated tau is at the center of aggregation and propagation; targeting it is considered the most promising approach to stopping tau spread.

Lee: Acetylated tau loses its normal function and is poorly degraded. Its pathological characteristics are clear, making it a target that explains “why it is bad tau.”

KBR: The key is to remove only “pathological tau” without affecting normal tau. How much has the strategy to minimize potential side effects during this process, and the safety data, been secured?

Yoon: Mechanistically, we do not expect significant side effects. The antibody targets tau aggregates outside the cell, while normal tau functions inside the cell. This mechanism differs from amyloid-related imaging abnormalities (ARIA) seen with amyloid antibodies. No issues were found in preclinical toxicity studies.

Jeong: No particular issues were identified in either tissue cross-reactivity or in vivo toxicity assessments.

KBR: How will clinical trials proceed after the technology transfer?

Yoon: Sanofi will fully lead future development. Sanofi placed great emphasis on development speed and clearly expressed its intent to accelerate the process. Our scale makes it difficult to handle the phase 2 Alzheimer's clinical trial and beyond. We judged that having a major global pharma company take it forward and develop it quickly is also best for the compound.

Lee: Alzheimer's clinical trials involve enormous patient numbers, long durations, and high costs. Our strategy was to secure evidence within the scope achievable in phase 1, recognizing that subsequent phases required the capabilities of a global partner.

KBR: What will your open innovation strategy and future direction be?

Yoon: For the time being, we plan to focus on our small-molecule and resistance-targeting anticancer programs. When the time comes to consider expansion in two to three years, various avenues like open innovation, licensing, or joint research will be open.

Kwak: Much work remains after tech transfer, like data transfer. If advantageous opportunities arise from platform screening, we can consider them flexibly.

KBR: Would you summarize the significance of this achievement in one sentence?

Yoon: It demonstrates the industrialization of an idea originating in academia, with preclinical, clinical, and BD teams working together to complete the journey to global technology transfer. This process itself proved Oscotec's new drug development capabilities.