4SC

4SC AG is a German biopharmaceutical company established in 1997, with its headquarters in Planegg-Martinsried. The company has historically focused on discovering and developing small-molecule drugs for cancer treatments, particularly in areas with significant unmet medical needs. Publicly traded on the Frankfurt Stock Exchange since December 2005, 4SC has navigated the complexities of the biotech industry through clinical development, partnerships, and various funding rounds, including a significant capital increase of €29 million in July 2015 to fund clinical trials.

The core of 4SC's business model revolves around the clinical development of its drug candidates and subsequent commercialization, either through partnerships with larger pharmaceutical companies or by marketing the drugs itself in specific regions. This strategy involves out-licensing partnered drug candidates and advancing its own pipeline through rigorous clinical trials. In 2016, for instance, 4SC sold its immunology portfolio and the operations of its subsidiary 4SC Discovery GmbH to BioNTech, sharpening its focus on epigenetic anti-cancer drugs.

The company's main therapeutic focus has been on epigenetic modulators, specifically histone deacetylase (HDAC) inhibitors. Its most advanced product candidate was Resminostat (Kinselby), an oral HDAC inhibitor developed as a maintenance therapy for cutaneous T-cell lymphoma (CTCL), a rare type of cancer. Resminostat works by causing an accumulation of acetylated histones, which can lead to the inhibition of tumor cell division and induce cancer cell death. Another key asset in its pipeline was Domatinostat (4SC-202), a selective inhibitor of class I HDACs, which also showed potential in treating various cancers by activating tumor suppressor genes and has been investigated in clinical trials for hematological malignancies.

However, the company faced a major setback in May 2025 when the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) issued a negative opinion regarding the market authorization application for Resminostat. Following this decision, 4SC announced the discontinuation of the development and commercialization of Resminostat, its sole remaining drug candidate. This led to the company ceasing its own operating business and initiating a process of capital reduction and delisting from the Frankfurt Stock Exchange to manage its financial situation.

Keywords: 4SC AG, biopharmaceutical, cancer treatment, epigenetic modulators, HDAC inhibitors, Resminostat, Kinselby, Domatinostat, cutaneous T-cell lymphoma, CTCL, clinical trials, drug development, oncology, small-molecule drugs, Planegg-Martinsried, European Medicines Agency, CHMP, stock exchange delisting, corporate restructuring, pharmaceutical partnerships