Calciphylaxis is a rare but incredibly dangerous condition that causes small blood vessels in the skin to become blocked by calcium buildup and blood clots. This leads to painful skin sores (necrosis) that do not heal easily. Because these open wounds are prone to severe infections, the outlook for patients is often grim; more than half of those diagnosed do not survive past the first year. Currently, there are no Food and Drug Administration (FDA) approved medications specifically designed to stop the progression of this disease. However, recent research has identified a specific culprit: Interleukin-6 (IL-6). The research team is looking at a drug called Tocilizumab to turn off the progression of the disease.

This project aims to investigate whether Tocilizumab can consistently stop the cycle of inflammation and clotting, providing a much-needed lifeline for patients facing this life-threatening diagnosis. Ten participants with calciphylaxis and end-stage kidney disease will be enrolled to receive 3 infusions of Tocilizumab, follow-ups on a weekly basis, during their trip to the dialysis unit, for a total of 16 weeks.

Inclusion Criteria:

• Must have a clinical diagnosis of calciphylaxis (calcific uremic arteriolopathy) as determined by a board-certified dermatologist or surgeon.

• Diagnosis must be supported by either:

  • Histopathology: A skin biopsy showing characteristic medial arteriolar calcification, subintimal fibrosis, or microvascular thrombosis.
  • Clinical Presentation: In cases where a biopsy is clinically contraindicated, the presence of characteristic ischemic or necrotic skin lesions in a distribution typical for calciphylaxis (e.g., adipose-rich areas like the abdomen, thighs, or buttocks).

• Must have advanced kidney disease, defined as:

  • End-Stage Kidney Disease (ESKD): Requiring maintenance hemodialysis or peritoneal dialysis.
  • Chronic Kidney Disease (CKD): Stage 4 or 5 [estimated Glomerular Filtration Rate (eGFR) < 30 mL/min/1.73m²].

• Participants must be able to understand and provide written informed consent. in accordance with local institutional and regulatory guidelines.

• Subjects of childbearing potential must agree to use highly effective contraception for the duration of the study and for at least 3 months following the final dose of Tocilizumab.

• Must be willing to undergo blood draws for systemic biomarker analysis (CRP, sTF) as outlined in the study schedule, and safety monitoring.

Exclusion Criteria:

• Presence of any active, clinically significant infection (bacterial, viral, fungal, or opportunistic) that, in the opinion of the investigator, would pose an unacceptable risk to the patient during IL-6 inhibition.

• Known history of diverticulitis, intestinal perforation, or active gastrointestinal ulceration, due to the increased risk of GI perforation associated with tocilizumab.

• Evidence of active tuberculosis (TB) or untreated latent TB [confirmed via positive Interferon-Gamma Release Assay (IGRA) or purified protein derivative (PPD) skin test].

• Evidence of active Hepatitis B [HBsAg positive, or HBcAb positive with detectable hepatitis B virus (HBV) DNA) or active Hepatitis C (HCV RNA positive]

• Absolute Neutrophil Count (ANC) < 1,500 cells/mm³.

  • Platelet count < 100,000 cells/mm³.
  • Hemoglobin < 8.0 g/dL.

• Baseline elevations of (alanine aminotransferase test (ALT) or aspartate aminotransferase test (AST) > 1.5 times the upper limit of normal (ULN).

• Known active malignancy or a history of malignancy within the last 5 years (excluding successfully treated non-melanoma skin cancer or carcinoma in situ of the cervix).

• History of multiple sclerosis or other central demyelinating disorders.

• Recent or planned use of other biological response modifiers (e.g., tumor necrosis factor (TNF)-alpha inhibitors, IL-1 receptor antagonists, or B-cell depleting agents) within 3 months prior to enrollment.

• Receipt of a live or attenuated vaccine within 4 weeks prior to the first dose, or planned vaccination during the study period and for 4 weeks following the final dose.

• Known hypersensitivity to tocilizumab or any of its excipients.

• Pregnant or breastfeeding women, or those planning to become pregnant during the study period.

• Individuals who are unable to provide personal informed consent and do not have a Legally Authorized Representative (LAR) available to provide consent on their behalf

• Any other concurrent medical or psychiatric condition that, in the investigator's judgment, would make the subject inappropriate for the study or interfere with safety evaluations.

• Prisoners