Histogen Inc. announced the initiation of its Phase 1/2 clinical trial of HST 003 to evaluate the safety and efficacy of human extracellular matrix implanted within microfracture interstices and the cartilage defect in the knee to regenerate hyaline cartilage in combination with a microfracture procedure. Clinical sites participating in the trial include: OasisMD in San Diego, CA, The Steadman Clinic in Vail, CO and Walter Reed Medical Center in Bethesda, MD.