It is advised to evaluate patients for tuberculosis infection prior to initiating treatment with ILUMYA. This drug may increase the risk of infection ^L1858. It is advisable to perform tests for current tuberculosis status, as this drug may lead to reactivation of latent infection ^{FDA label}.

A common issue for monoclonal antibody drugs is the development of antibodies to the drugs, thus rendering them less effective or completely ineffective ^L1861. A clinical trial was done to assess antibody development to this drug ^L1858, ^{FDA label}. Up until week 64, approximately 6.5% of subjects treated with ILUMYA 100 mg developed antibodies to tildrakizumab. Of the subjects who developed antibodies to tildrakizumab, approximately 40% (2.5% of all patients receiving ILUMYA) had antibodies that were considered neutralizing. The development of neutralizing antibodies to tildrakizumab was associated with lower serum tildrakizumab concentrations and decreased efficacy ^{FDA label}.

Most common (? 1% and at a higher rate than placebo) adverse reactions associated with ILUMYA treatment are upper respiratory infections, injection site reactions, and diarrhea ^L1858.

Cases of angioedema and urticaria occurred in ILUMYA treated subjects in various clinical trials. If a hypersensitivity reaction occurs, the drug should be discontinued immediately and appropriate therapy should be initiated ^{FDA label}.

In an embryo-fetal study, subcutaneous doses up to 300 mg/kg tildrakizumab were given to pregnant cynomolgus monkeys once every two weeks during organogenesis to 118 days gestation (22 days from parturition). No maternal or embryo-fetal toxicities were seen at doses up to 300 mg/kg (159 times the MRHD of 100 mg, based on AUC comparison). Tildrakizumab crossed the placenta in monkeys ^{FDA label}.