The average success rate for healing and remission of complex perianal fistulas, idiopathic or Crohn's-related, is approximately 50%. These abnormal connections between the rectum and the outside skin remain a major clinical challenge in need of new treatments aimed at tissue repair. Platelet-derived growth factor drives wound healing and tissue regeneration, and manufactured PDGF is currently used to heal diabetic foot ulcers and regenerate bone in periodontal and orthopedic patients. Manufactured recombinant human PDGF has the potential to improve the success rate for complete healing of complex perianal fistulas, reduce the recurrence rate due to reopening of the fistula tract, and avoid complications associated with routine surgical interventions.