Kadmon clinical POC data raise expectations for IPF drug

A chest radiograph of a patient with IPF. (IPFeditor/CC BY-SA 3.0)

Kadmon has posted clinical proof-of-concept data on its idiopathic pulmonary fibrosis (IPF) candidate KD025. The ROCK2 inhibitor had a stronger effect on forced vital capacity (FVC) than standard of care, but the small, open-label nature of the study and lack of detail in the top-line data leave scope for doubts about its efficacy.

As of the start of the month, investigators had data on 20 patients who took KD025 for 24 weeks and nine patients who received standard of care. All the participants had previously been offered Roche’s Esbriet or Boehringer Ingelheim’s Ofev, although only 44% had actually been treated with the drugs.

The median FVC decline in the KD025 arm was 48 mL, compared to a drop of 175 mL in the control cohort. That result sent Kadmon’s stock up 20% after hours and caught the eye of analysts that track the biotech.

“The absolute improvement of 127 mL between arms surpasses our bar of 45 to 85 mL seen with existing therapies,” Jefferies analyst Biren Amin wrote in a note to investors. 

It is currently unclear how meaningful the cross-trial comparison is, though. Kadmon’s statement to disclose the results lacks any information about the baseline characteristics of participants in its trial. The only signpost is that the change in percent predicted FVC in the KD025 arm was 1%, compared to 2% in the control group. Kadmon has yet to share p values.

Those details or the more rigorous tests that await KD025 may ultimately paint a bleaker picture of the drug’s future. But for now Kadmon can claim some success against its objectives of validating its platform and the potential of inhibiting ROCK proteins to treat IPF. The potential of the mechanism is underpinned by evidence ROCK2 mediates cellular responses that lead to fibrosis.  

If Kadmon can generate positive data in a longer, double-blind phase 2, it could have a significant drug on its hands. For now, Kadmon lacks data to show KD025 can best the incumbent drugs sold by Roche and Boehringer or more advanced pipeline prospects such as FibroGen’s pamrevlumab.