Callio Therapeutics Appointed New Chief Scientific Officer
The company has tapped former Boundless Bio executive Chris Hassig to steer its pipeline of dual-payload oncology drugs.
Updated on Sept. 28, 2026 in Biotech
Callio Therapeutics has appointed Chris Hassig, who holds a PhD in Molecular and Cellular Biology, as its new Chief Scientific Officer. The move aims to accelerate the development of the firm's dual-payload antibody-drug conjugate (ADC) platform and its lead clinical candidate, CLIO-8221.
Why it matters
Hassig’s appointment brings two decades of oncology drug discovery experience to the company's research organization. This leadership change comes as Callio seeks to expand the clinical study of CLIO-8221, an antibody-drug conjugate targeting HER2, into China.
Callio Therapeutics focuses on developing dual-payload antibody-drug conjugates, a class of therapeutics that use an antibody to deliver two distinct drug cargos directly to targeted cells. The firm's lead candidate, CLIO-8221, is currently in clinical testing with its first patient having received a dose in March 2026.
The players
Callio Therapeutics
A biotechnology company specializing in the development of dual-payload antibody-drug conjugate therapeutics.
Chris Hassig
A PhD in Molecular and Cellular Biology who previously served as Chief Scientific Officer at Boundless Bio.
The details
Hassig will oversee the company's research and discovery organization, which leverages proprietary linker technologies to attach two different therapeutic agents to a single antibody. This approach aims to enhance efficacy in targeting HER2, a protein often overexpressed in various cancers. The company currently conducts trials across multiple global sites including the United States and Australia.
Timeline
March 2026: First patient dosed with CLIO-8221.
September 28, 2026: Chris Hassig appointed as Chief Scientific Officer.
The Tech Race
The development of HER2-targeting antibody-drug conjugates remains a highly competitive field in oncology. Callio Therapeutics is now positioning its dual-payload platform to compete with existing established therapies by potentially increasing the therapeutic window for patients.
The transition in leadership marks an internal operational change aimed at advancing the clinical pipeline for cancer patients. Access to the experimental CLIO-8221 therapy remains restricted to clinical trial participants until future regulatory milestones are reached.
The takeaway
Callio Therapeutics is now focused on its goal of extending the CLIO-8221 clinical trial into the Chinese market. Observers should monitor future regulatory filings or site expansions as indicators of the company's platform success.
Further reading
For more on the current landscape of therapeutic drug development, visit Biotech.
