Experimental drug for rare inflammatory disease shows early promise but trial cut short

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

Inclusion Criteria: Individuals who meet all of the following criteria are eligible for enrollment as study participants: 1. Participant must be able to understand and provide informed consent and be willing to comply with study procedures and follow up. 2. Are at least 18 years of age and not older than 70 years of age at screening. 3. Meet the ACR/EULAR Classification Criteria for IgG4-RD \[30, 31\]. 4. Have active disease based at screening on an IgG4-RD RI ≥4, with disease manifestations in at least two organ systems. 5. May have newly-diagnosed or relapsing disease at screening. Relapsing disease is defined as IgG4-RD that has previously been in remission but is now active again. 6. May be on treatment or off treatment for IgG4-RD at the time of screening. If on treatment, must be willing to discontinue those other treatments before the baseline visit. 7. No history of severe allergic reactions to monoclonal antibodies. 8. Female participants of childbearing potential must have a negative pregnancy test upon study entry. 9. Female participants of childbearing potential and male participants with a partner of childbearing potential must agree to consistently and correctly use FDA approved highly effective methods of birth control for the entire duration of the study and 6 months after last elotuzumab infusion. 10. Immunization with one of the FDA authorized or licensed SARS-CoV-2 vaccines as per CDC recommendations at the time of informed consent is required for study entry. Vaccinations must have been completed at least 2 weeks prior to start of study therapy. Exclusion Criteria: Individuals who meet any of these criteria are not eligible for enrollment as study participants: 1. Presence of a condition other than IgG4-RD that (e.g., asthma) is likely to require systemic Glucocorticoids (GC) for disease control during the period of the trial. 2. Malignancy within 5 years (except successfully treated in situ cervical cancer, resected squamous cell or basal cell carcinoma of the skin.) 3. The following lab values as indicators of hepatic dysfunction: 1. Serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) greater than three times the upper limit of normal (ULN) 2. Total bilirubin \> two times the ULN unless caused by Gilbert's disease. Gilbert's disease with total bilirubin \> three times ULN. 3. Serum albumin \< 2.5 gm/dL. 4. Evidence of another uncontrolled condition which, in the judgment of the investigator, could interfere with participation in the trial according to the protocol. 5. Active infection requiring hospitalization or treatment with systemic antimicrobial agents within the 30 days prior to treatment allocation/randomization. 6. Prior use of rituximab or other B cell depleting agents within 9 months of enrollment unless B cells have been demonstrated to have repopulated. 7. Use of any investigational agent or biologic and non-biologic DMARDs within 5 half-lives of the agent (or 6 months if the half-life is unknown) prior to enrollment. 8. Any of the following laboratory tests at the Screening Visit: 1. White blood cell count (WBC) \< 3.0 x 103/µL. 2. Absolute neutrophil count (ANC) \< 1.5 x 103/µL. 3. Hemoglobin \< 10 g/dL. 4. Platelet count \< 75 x 109/L. 5. Estimated glomerular filtration rate (eGFR) ≤ 45 ml/minute/1.73 m2. 9. The use of supplemental oxygen at baseline. 10. At or within 90 days of screening: Positive Interferon-Gamma Release Assay (IGRA). Indeterminate IGRAs must be repeated (with same or other IGRA per local policy) and shown to be negative. Alternatively, if the assay remains indeterminant, a participant must have a negative PPD. Finally, if the participant has had the Bacille Calmette-Guerin (BCG) vaccine or has some other condition complicating the interpretation of TB testing, consultation with infectious disease specialist must be obtained before receipt of the first investigational infusion. a. Participants diagnosed with latent TB are eligible but must have received appropriate prophylaxis for 30 days before their first investigational infusion. 11. Medical history or serologic evidence at Screening of chronic infections including: 1. Human immunodeficiency virus infection. 2. Hepatitis B as indicated by surface antigen or hepatitis B core antibody positivity 3. Hepatitis C as indicated by anti-hepatitis C antibody positivity; if a participant is Hepatitis C antibody positive, they will be eligible to participate in the study if he/she is negative for viral load at Screening. 12. Live vaccines within 8 weeks of initiating study therapy. 13. Participant is pregnant or breastfeeding, or planning a pregnancy while enrolled in the study. 14. Substance use disorder, including the recurrent use of alcohol and/or drugs within the past year associated with clinically significant impairment associated with failure to meet major responsibilities at work, school, or home. 15. IgG4-RD that is dominated primarily by advanced fibrotic lesions. Specifically, participants whose disease manifestations consist only of 1. retroperitoneal fibrosis, 2. fibrosing mediatinitis, 3. sclerosing mesenteritis, or 4. Riedel's thyroiditis. Participants with these disease manifestations can be included, however, only if they have disease in 2 organ systems that is not of an advanced fibrotic nature and otherwise meet the Inclusion and Exclusion Criteria. 16. Evidence a SARS-CoV-2 (COVID-19) infection started within the 30 days prior to treatment allocation/randomization. Participants diagnosed with SARS-CoV-2 (COVID-19) infection more than 30 days prior to treatment allocation/randomization must have symptoms resolved and be deemed fit to participate in the trial.