ADC Therapeutics Cuts Workforce, Closes UK R&D to Focus on Key Cancer Therapies

Highlights

• ADC Therapeutics to close its U.K. R&D site and cut 30% of its workforce by September 30.
• The company is discontinuing multiple early-stage solid tumor ADC programs, including those targeting Claudin-6 and ASCT2.
• Focus shifts to Zynlonta and a preclinical ADC targeting prostate-specific membrane antigen (PSMA).
• Restructuring costs are projected to total $6 million to $7 million.
• Recent clinical terminations include ADCT-602, ADCT-601, and ADCT-901 due to efficacy and strategic reprioritization concerns.

U.K. Research Facility to Close as Workforce Shrinks

ADC Therapeutics, a Swiss-based biopharmaceutical company, is undergoing significant corporate restructuring following recent clinical setbacks. According to a June 11 filing with the Securities and Exchange Commission (SEC), the company will shutter its U.K. research and development facility and reduce its global workforce by 30%. These measures are expected to be completed by September 30.

The decision comes in the wake of the company’s recent move to drop its only clinical-stage candidate, ADCT-602, in May. The company stated, “ADC Therapeutics is shutting down a U.K. research site and laying off 30% of its workforce.”

Early-Stage Programs Abandoned

As part of the reorganization, ADC Therapeutics is discontinuing development of several preclinical programs, particularly in the solid tumor segment. The company is pulling back from work on exatecan-based antibody-drug conjugates (ADCs) targeting Claudin-6 and ASCT2. These decisions signal a strategic realignment toward assets with greater potential for return on investment.

In the SEC filing, ADC Therapeutics detailed, “The Swiss biopharma is also discontinuing early development for some preclinical programs in solid tumors, including exatecan-based antibody-drug conjugates targeting Claudin-6 and ASCT2.”

Strategic Focus Shifts to Zynlonta and PSMA ADC

With the discontinuation of non-core projects, ADC Therapeutics plans to concentrate its resources on two primary programs: the FDA-approved cancer monoclonal antibody Zynlonta and a preclinical-stage ADC targeting prostate-specific membrane antigen (PSMA).

The company clarified its future direction in the SEC filing, stating, “The restructuring is designed to channel resources toward the company’s approved cancer monoclonal antibody, Zynlonta, and a preclinical antibody-drug conjugate chasing prostate-specific membrane antigen.”

Financial Impact and Restructuring Costs

As part of the cost-saving initiative, ADC Therapeutics expects to incur expenses in the range of $6 million to $7 million associated with the restructuring plan. These costs include severance payments, site closure expenditures, and other related liabilities.

The SEC filing noted, “The biopharma also expects to pay out about $6 million to $7 million tied to the restructuring.”

Recent Setbacks Prompt Strategic Reassessment

The current changes come on the heels of a difficult period for ADC Therapeutics. In May 2025, the company halted its Phase 1/2 trial of ADCT-602, a CD22-targeted therapy for relapsed or refractory B-cell acute lymphoblastic leukemia, citing unsatisfactory clinical data.

Previously, in November 2024, the company discontinued development of ADCT-601, an AXL-based candidate aimed at sarcoma, pancreatic cancer, and non-small cell lung cancer. A similar decision was made in January 2024 for ADCT-901, a KAAG1-targeted ADC, which was scrapped due to “l(fā)imited signs of efficacy … and to reallocate capital to prioritized programs.”