Axatilimab in Combination With Extracorporeal Photopheresis (ECP) in Chronic Graft-versus-Host Disease

Inclusion criteria

• Recipient of allogeneic hematopoietic cell transplantation (HCT).
• Age greater or equal to 12.
• Chronic GVHD per 2014 National Institutes of Health Consensus Criteria (NCC) (Jagasia et al. 2015) or overlap syndrome requiring new therapy in patients with at least 2 prior lines of therapy, steroid refractoriness, or steroid dependence:

• Prior systemic lines of therapy may include corticosteroids, calcineurin inhibitor (CNI) or sirolimus, or other systemic immunosuppressive agent such as ruxolitinib, belumosudil, or ibrutinib. GVHD prophylaxis does not count as a prior line of therapy.
• Steroid refractory is defined as any of the following criteria:

• i. Manifestations progress despite the use of ≥ 1 mg/kg/day prednisone for at least 1 week
• ii. Manifestations persist without improvement despite treatment with ≥ 0.5 mg/kg/day or 1 mg/kg every other day for at least four weeks.
• iii. Recurrence after a CR, or
• iv. Progression after a PR.
• Steroid dependence is defined as inability to control cGVHD symptoms while tapering prednisone below 0.25 mg/kg/day on at least two occasions separated by at least 8 weeks. There must be evidence of clinically active cGVHD.
• For patients receiving approved or commonly used agents, all GVHD systemic treatments should be discontinued except for corticosteroids and drugs being continued from GVHD prophylaxis at screening.
• Eastern Cooperative Oncology Group (ECOG) performance status 0-3 as assessed at Screening.
• Platelet count > 50,000 platelets/μL and absolute neutrophil count > 1,000 cells/μL as measured at Screening.
• Aspartate aminotransferase (AST), alanine aminotransferase (ALT) ≤ 2.5 x upper limit of normal (ULN), unless attributed to presumed cGVHD as measured at Screening.
• Stable dose of corticosteroids for at least 14 days prior to treatment.
• Sexually mature individuals must use contraception as described in Section 4.12. For individuals less than 18 years of age, sexual maturity will be determined as per treating pediatrician.

Exclusion criteria

• Pregnancy or breast-feeding.
• Active relapse of underlying malignancy.
• History or the presence of interstitial pneumonitis or drug-related pneumonitis.
• Active gastrointestinal (GI) bleeding.
• Inability to tolerate volume shifts associated with ECP (e.g., inadequate renal, hepatic, pulmonary and cardiac function (ejection fraction (EF) < 40%) per Investigator discretion.
• History of myositis.
• History of splenectomy.
• History of pancreatitis.
• History of other malignancy (within 3 years of Screening) unless treated with curative intent and approved by Principal Investigator (PI).
• Significant, uncontrolled, or active comorbid conditions or are unable to adhere to the study requirements.
• Acquired Immune Deficiency Syndrome (AIDS) or active hepatitis B (Hep B) or active hepatitis C (Hep C) infection.
• Prior colony-stimulating factor-1 (CSF-1R) targeted therapies.
• Prior history of ECP treatment failure or intolerance.
• Intolerance to methoxsalen, heparin, or citrate products.
• Patients with aphakia due to risk of increased retinal damage or photosensitive disease (albinism, systemic lupus erythematosus, porphyria).
• Lack of stable IV access. Acceptable forms include central venous catheter, peripherally inserted central catheter (PICC), or peripheral IV line per institutional guidelines.
• Insurance denial of coverage for the ECP procedure.