Astellas Pharma Inc. announced that it has voluntarily paused screening and dosing of additional participants in its ASPIRO clinical trial evaluating AT132 in patients with X-linked Myotubular Myopathy. This decision follows the reporting of a recent serious adverse event (SAE) in a study participant due to abnormal liver function tests (LFTs) observed in the weeks following dosing of the AT132 investigational gene therapy product at a lower dose (1.3x1014 vg/kg). Astellas voluntarily halted screening and dosing, reported the SAE to regulatory agencies, and is engaged in dialogue with regulators about this SAE. At this time, an Investigational New Drug (IND) clinical hold has not been issued. In the U.S., an IND clinical hold is an order issued by the U.S. Food and Drug Administration (FDA) to the sponsor of a clinical trial to delay a proposed clinical trial or suspend an ongoing clinical trial. If Astellas receives a clinical hold letter, it will review the content and determine next steps.