Alentis Therapeutics' anti-Claudin-1 (CLDN1) antibody-drug conjugate (ADC) ALE.P02 has received Fast Track designation from the FDA as a potential treatment for patients with CLDN1-positive squamous solid tumors. This designation aims to expedite the development and review of drugs addressing serious conditions with unmet medical needs. The first-in-class ADC, which comprises a tubulin inhibitor linked to an antibody targeting the CLDN1 epitope, is poised to enter a phase 1/2 clinical trial in early 2025.
The trial, cleared by the FDA in October 2024 under an investigational new drug (IND) application, will assess the safety and efficacy of ALE.P02 in patients with CLDN1-positive squamous solid tumors. Squamous cell carcinomas, which can arise in various organs, often overexpress CLDN1, making it a promising therapeutic target.
Rationale Behind CLDN1 Targeting
CLDN1, normally hidden within tight junctions of healthy cells, plays a role in cell binding. However, in squamous solid tumors, CLDN1 is overexpressed and exposed, making it accessible to targeted therapies like ALE.P02. This approach aims to selectively target tumor cells while sparing healthy tissue.
"Squamous cancers of various origin have been shown to overexpress CLDN1, making ALE.P02 a promising ADC to address the unmet medical needs of these patients," said Tony S. K. Mok, MD, professor of clinical oncology at the Chinese University of Hong Kong.
Alentis' CLDN1-Directed ADC Pipeline
Alentis Therapeutics is also developing ALE.P03, another CLDN1-directed ADC. While both ADCs target CLDN1, ALE.P03 utilizes a topoisomerase I inhibitor as its cytotoxic payload. Preclinical data for both agents have demonstrated selective binding and internalization into CLDN1-positive tumor cells, leading to tumor growth inhibition and CLDN1-expression modulation in vivo. Notably, single doses of either ALE.P02 or ALE.P03 resulted in complete tumor regression in patient-derived xenograft models compared to control ADCs.
Good laboratory practice toxicology studies are ongoing for ALE.P03.
Leadership Perspective
"We are encouraged by the FDA’s recognition of ALE.P02’s potential as a treatment for CLDN1-positive squamous cancers," stated Roberto Iacone, chief executive officer of Alentis Therapeutics. Luigi Manenti, chief medical officer of Alentis Therapeutics, added, "We have set out to develop ALE.P02 in the most rational way, following CLDN1 science and the clinical understanding of squamous cancers. The FDA’s support in this endeavor is certainly motivating."
