KaloBios Pharmaceuticals, Inc. (KBIO)

KaloBios Pharmaceuticals, Inc. was a South San Francisco biotechnology company that developed monoclonal antibodies using its Humaneered technology. Its programs targeted conditions such as Pseudomonas lung infections in cystic fibrosis patients and certain cancers, and its lead candidates included antibodies against the GM-CSF signaling pathway. Its approach aimed to produce antibodies closely matched to human proteins, which was intended to lower the chance of immune reactions in patients.

The company completed its Nasdaq initial public offering in early 2013 under the symbol KBIO. Clinical setbacks followed, and by late 2015 KaloBios had cut most of its staff and announced plans to wind down operations, which pushed the stock to very low levels. The company partnered with large drug makers on some programs, but those collaborations did not lead to approved products, and its cash runway steadily shortened.

In November 2015 a group led by Martin Shkreli, then known for raising the price of the drug Daraprim at Turing Pharmaceuticals, bought a controlling stake. The stock rose by several thousand percent in a few days, Shkreli became chief executive and chairman, and he proposed acquiring rights to treatments for Chagas disease. The sudden rally attracted heavy trading by retail investors and short sellers, and it made KaloBios one of the most talked-about stocks of that period.

On December 17, 2015, Shkreli was arrested on securities fraud charges tied to his earlier companies, unrelated to KaloBios. KaloBios dismissed him, its shares were halted, and Nasdaq moved to delist the stock, citing the arrest and the company's failure to file its third-quarter report. The company filed for Chapter 11 protection at the end of December 2015, and its shares were removed from Nasdaq.

KaloBios emerged from bankruptcy in mid-2016 and its shares traded over the counter. It later renamed itself Humanigen, Inc. and developed lenzilumab, a GM-CSF antibody tested against COVID-19, before Humanigen itself filed for bankruptcy in 2024. The KBIO ticker was not used again for the company after the Nasdaq delisting. Humanigen's own shares were later listed on Nasdaq, but the company ran out of money after lenzilumab failed to win emergency authorization.