KaloBios Pharmaceuticals

The company emerged from bankruptcy in July 2016 with $14 million in new financing and a restructured focus on rare and neglected diseases. Under the new leadership of Chairman and CEO Dr. Cameron Durrant, KaloBios shifted its pipeline to prioritize two main candidates: benznidazole for Chagas disease and the monoclonal antibody lenzilumab for chronic myelomonocytic leukemia (CMML). Benznidazole, an older drug, was being developed with the aim of securing a valuable government voucher for treating a neglected tropical disease. Lenzilumab (formerly KB003), a proprietary antibody, targets granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine implicated in inflammatory responses and the growth of certain cancer cells.

In August 2017, KaloBios rebranded itself as Humanigen, Inc., to distance itself from its troubled past and reflect its new focus on its proprietary "Humaneered" antibody technology. As Humanigen, the company continued the development of lenzilumab, expanding its potential applications to include preventing dangerous side effects of CAR-T cancer therapies and treating the "cytokine storm" associated with severe COVID-19 cases. Despite some promising early data for lenzilumab in COVID-19 patients, the company ultimately faced further financial hardship. Humanigen filed for Chapter 11 bankruptcy reorganization again in January 2024.