Charting New Paths in Oncology: Insights from Dr. Alberto Toso, Chief Scientific Officer of Alentis Therapeutics

When Dr. Alberto Toso joined Alentis Therapeutics in 2021 as its ninth employee, the company had no oncology pipeline, no clinical data, and no clear development path—only a bold vision and the willingness to explore uncharted scientific territory. Fast forward just three years, Alentis closed an oversubscribed $181.4 million Series D financing round—the largest biotech raise in Switzerland in 2024 and is rapidly advancing the world’s first anti-Claudin-1 (CLDN1) antibody-drug conjugates (ADCs) through clinical development. At the WuXi Executive Breakfast in Basel, held alongside Swiss Biotech Day, Dr. Toso, Chief Scientific Officer of Alentis, reflected on this remarkable transformation and shared his personal journey of navigating uncertainty, driving innovation, and building momentum in the field of oncology.

In November 2024, Alentis Therapeutics achieved a significant milestone by raising $181.4 million in an oversubscribed Series D financing round. This funding, led by OrbiMed with co-leads Novo Holdings and Jeito Capital, will support the clinical development of two CLDN1-targeting ADCs, ALE.P02 and ALE.P03.

Dr. Toso highlighted the rapid progression of Alentis’ lead ADC programs—from concept to clinical stage in under three years. “When we started, the ADC programs were just an idea,” he recalled. “We had no choice but to act and lay the path as we walked it.” Entering the highly competitive ADC field, the Alentis team leveraged their long-standing expertise in CLDN1 to design the first anti-CLDN1 ADCs. Then they expedited the development despite the novelty of the target in oncology and the absence of established benchmarks.

That bold approach paid off, resulting in two first-in-class ADCs progressing through early clinical studies today. Dr. Toso acknowledged the vital support of WuXi AppTec and other collaborators throughout this journey. “Your flexibility truly enabled our success,” he noted.

Looking ahead, Alentis continues to focus on CLDN1 biology, with efforts underway to develop what Alentis calls the next generation of CLDN1 moleculesthat could offer more precise targeting and expand treatment to an even wider patient base. “I hope we can transform the lives of patients, especially in oncology,” Dr. Toso said.

Reflecting on Alentis’ growth—from a nine-person team to a clinical-stage biotech capturing global attention—Dr. Toso expressed hope that their journey marks just the beginning of a broader surge in the Swiss biotech ecosystem, ultimately benefitting more people living with cancer.