The US Food and Drug Administration (FDA) has cleared an investigational new drug (IND) application for CUSP06, allowing its manufacturer OnCusp Therapeutics to start a Phase I clinical trial assessing its use for ovarian cancer and other advanced solid tumours.

The antibody drug conjugate targets cadherin-6, which is a protein overexpressed in cancer cells – including those found in the ovaries. The candidate has a protease-cleavable linker combined with a topoisomerase-1 inhibitor payload that kills cells by the “bystander effect”. The biopharma claims its asset has a stronger effect than competitor antibody drug conjugates, and reported potent anti-tumour activity in preclinical models in April 2023.

OnCusp Therapeutics says it is developing its drug to help tackle chemoresistance, one of the biggest challenges in cancer therapy. The exatecan payload in CUSP06 is a weak substrate for drug efflux pumps that cause chemoresistance.

The dose-escalating Phase I trial will assess the safety and tolerability of CUSP06 in patients with platinum-refractory/resistant ovarian cancer and other advanced solid tumours. The company will aim to find a maximum tolerated dose and a recommended expansion dose.

OnCusp Therapeutics acquired exclusive global rights outside of China for CUSP06 from Multitude Therapeutics in June 2022.

“We are delighted to announce the IND approval for our flagship programme, CUSP06, which has demonstrated excellent anti-tumor efficacy across diverse in vivo cancer models with both high and low CDH6 expression,” stated Dr. Bing Yuan, Chairman and CEO of OnCusp Therapeutics.

“This achievement is a testament to the dedication and expertise of our exceptional team. As our first asset to receive FDA approval for clinical trials, this marks a transformative milestone for OnCusp and reaffirms our commitment to developing game-changing treatments for cancer patients.”