Could a common arthritis drug help PSC patients?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Age 15-80 2. A diagnosis of PSC for at least 6 months based upon cholangiography (ERCP or MRCP) demonstrating intrahepatic and/or extrahepatic biliary strictures, beading or irregularity consistent with PSC. 3. ALP \> 1.67 times the upper limit of normal (ULN) at screening 4. Inflammatory bowel disease 5. Subject must either be on a stable dose of ursodeoxycholic acid for \> 6 months prior to screening or have been discontinued \> 4 weeks prior to screening (enrollment of patients who are on UDCA will be limited to 50% of all enrolled patients). We are recruiting remotely throughout the United States so an individual anywhere in the US with PSC and IBD can be enrolled. Exclusion Criteria: 1. Anticipated need for liver transplant within one year as determined by Mayo PSC risk score treatment 2. Evidence of decompensated liver disease such as variceal bleeding, ascites, or hepatic encephalopathy. 3. Evidence of advanced liver disease including MELD score \> 10, bilirubin \> 3.0, platelet count \< 100,000; or INR \> 1.4 4. Concomitant chronic liver disease including alcohol related liver disease, chronic hepatitis B or C infection, haemochromatosis, Wilson's disease, alpha1-antitrypsin deficiency, non-alcoholic steatohepatitis, autoimmune hepatitis, or primary biliary cholangitis 5. Secondary causes of sclerosing cholangitis 6. Known intolerance to sulfasalazine (including but not limited to allergy to sulfa or mesalamine) or folic acid 7. History of cholangiocarcinoma or colon cancer within 5 years 8. History of colectomy with \> 1/3 bowel resected 9. Treatment with any investigational agents, within two months or 5 half-lives of the investigational product, whichever is longer. 10. Active illicit drug or alcohol abuse 11. Current or past use of sulfasalazine within 6 months of enrollment. 12. Need for chronic use of antibiotics 13. Evidence of bacterial cholangitis within 6 months of enrollment 14. In patients with Ulcerative Colitis, simple clinical colitis activity index of \> 4 or, if Crohn's disease, a Harvey-Bradshaw index of \> 5 15. Chronic kidney injury (eGFR \< 59) 16. Pregnancy or lactation