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# FDA Clinical Hold on Aptose Drug Seeks CMC Information
- URL: https://www.fdaweb.com/fda-clinical-hold-on-aptose-drug-seeks-cmc-information/
- Published: 2016-10-13T12:00:00.000Z
- Updated: 2026-09-14T21:39:20.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5137072

FDA has placed a clinical hold on an Aptose Biosciences Phase 1b clinical trial of APTO-253 in patients with hematologic cancers, requesting additional information. The agency is requesting the complete chemistry, manufacturing and control information for the final GMP drug substance and drug product intended for the clinic, according to the company.

Earlier this year, FDA placed a hold on the trial after a clinical site experienced stoppage of the infusion pump during an IV infusion caused by back pressure as a result of clogging of the in-line filter. Aptose determined the root cause was a chemistry-based issue with the molecule, and says it is now working with a drug product that does not cause filter clogging or pump stoppage during mock infusion studies performed to confirm the acceptability of the updated product through the clinical infusion procedures. “Such improvements to the APTO-253 manufacturing process required to address the filter clogging event will be incorporated into a chemistry, manufacturing and control amendment to our Investigational New Drug application,” the company says.