ADC Therapeutics Announces Major Restructuring Amid Pipeline Setbacks

ADC Therapeutics, a Swiss biopharma company, has unveiled a significant restructuring plan following a series of pipeline setbacks. The company is shuttering its U.K. research and development site, discontinuing several preclinical programs, and reducing its workforce by 30% in a bid to refocus its resources on key assets.

R&D Consolidation and Program Cuts

The restructuring, announced in a June 11 filing with the Securities and Exchange Commission (SEC), will see ADC Therapeutics close its U.K. R&D facility by September 30, 2025. Alongside this closure, the company is halting early development of multiple preclinical programs in solid tumors, including exatecan-based antibody-drug conjugates targeting Claudin-6 and ASCT2.

These moves are part of a broader strategy to channel resources toward the company's approved cancer monoclonal antibody, Zynlonta, and a preclinical antibody-drug conjugate targeting prostate-specific membrane antigen. The restructuring is expected to incur costs of approximately $6 million to $7 million.

Recent Pipeline Challenges

The announcement comes on the heels of several pipeline setbacks for ADC Therapeutics. In May 2025, the company ended work on ADCT-602, its CD22-targeted candidate for relapsed or refractory B-cell acute lymphoblastic leukemia, following disappointing clinical data from a phase 1/2 trial.

This decision followed earlier terminations of two other clinical programs. In November 2024, ADC Therapeutics discontinued ADCT-601, an AXL-based candidate for sarcoma, pancreatic cancer, and non-small cell lung cancer. Similarly, in January 2024, the company halted development of ADCT-901, a KAAG1-targeted therapy, citing "limited signs of efficacy" and the need to reallocate capital to prioritized programs.

Workforce Reduction and Financial Implications

As part of the restructuring, ADC Therapeutics will lay off 30% of its workforce. This significant reduction in personnel, coupled with the R&D site closure and program discontinuations, reflects the company's efforts to streamline operations and conserve resources in the face of recent clinical disappointments.

The financial impact of these changes is expected to be substantial, with the company projecting restructuring-related costs of $6 million to $7 million. However, ADC Therapeutics aims to emerge from this period of consolidation with a more focused approach to its drug development pipeline and commercialization efforts.