ADC Therapeutics, Aldeyra start off New Year with program discontinuations

For ADC Therapeutics and Aldeyra, ringing in the new year means leaving certain programs behind in 2023.   

Swiss biotech ADC Therapeutics is discontinuing development of ADCT-901, an antibody drug conjugate (ADC) targeting KAAG that was being evaluated in a phase 1 trial for patients with advanced solid tumors, including platinum-resistant ovarian cancer and triple-negative breast cancer. The trial had a primary completion date in April 2024, according to

The company said “limited signs of efficacy in the dose escalation phase” prompted the discontinuation, according to a Jan. 4 release. The biotech will focus its resources on preclinical activities and its remaining two clinical assets: ADCT-601, which is being tested in a phase 1b trial against various solid tumors, and ADCT-602, which is being assessed in a phase 1 trial in collaboration with MD Anderson Cancer Center for patients with relapsed or refractory acute lymphoblastic leukemia.

ADC Therapeutics ended 2023 with $278.5 million in cash and cash equivalents on hand, money that is expected to stretch into the fourth quarter of 2025. The company expects its belt-tightening to cut total operating expenses for both 2023 and 2024 in comparison to 2022. 

Meanwhile, Aldeyra Therapeutics has deprioritized ADX-629, an investigational, orally administered reactive aldehyde species (RASP) modulator that was designed to tackle chronic cough and idiopathic nephrotic syndrome. The Massachusetts-based biotech cited regulatory and trial feasibility challenges for the discontinuation in each respective indication.  

Aldeyra has instead turned its focus to a new preclinical RASP modulator program in metabolic disease.

The discontinuation follows a November rejection from the FDA for Aldeyra’s dry eye drug reproxalap, though the biotech said at the time that it will zip through a brand new trial to get the application back to the agency within the first half of 2024.

The official complete response letter states that Aldeyra failed to demonstrate “efficacy in treating ocular symptoms associated with dry eyes,” with the FDA requesting a new trial to show a positive effect on ocular symptoms of dry eye disease.    

Last week, Aldeyra received feedback from the FDA on reproxalap and has subsequently amended the proposed clinical trial protocol and statistical analysis plan, according to a Jan. 4 release.