Long Term Safety of Vedolizumab (MLN0002) in Patients With Ulcerative Colitis and Crohn's Disease

An adverse event (AE) is any untoward medical occurrence in a patient administered a pharmaceutical product, which does not necessarily have a causal relationship with the treatment. The investigator systematically collected information adequate to determine both the outcome and severity of the AE, and whether or not it was drug-related or met the criteria for classification as a serious adverse event (SAE). An SAE was defined as an AE that resulted in (or posed risk for) death, inpatient hospitalization (or prolonging hospitalization), or congenital, persistent or significant disability/incapacity.

The intensity for each AE was defined according to the following criteria:

Mild: Awareness of sign or symptom, but easily tolerated; Moderate: Discomfort enough to cause interference with normal daily activities; Severe: Inability to perform normal daily activities.

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are enzymes in the blood.

At every visit, before receiving study treatment participants were evaluated by clinic staff for signs of PML using a PML symptom checklist.

Vedolizumab serum concentrations were measured from serum samples collected for pharmacokinetic (PK) analysis within 2 hours prior to dosing. The original protocol specified that PK parameters, including but not limited to minimum plasma concentration (Cmin), were to be estimated; however, due to intrapatient dose modification with Amendment 1, it was no longer feasible to perform a full PK parameter estimation. The summaries of pre-infusion data (i.e., trough levels) are presented at time points where at least 50% of participants had quantifiable vedolizumab concentrations, using a value of 0 for results below a measurable range. This provides information on the pharmacokinetic behavior of vedolizumab when administered as long-term therapy.

The target of vedolizumab is α4β7 integrin, a receptor found on inflammatory immune cells that guides these inflammatory cells to the gut and binds to the Mucosal Addressin Cell Adhesion Molecule-1 (MAdCAM-1) on gut endothelial cells. The extent of the α4β7 receptor saturation by vedolizumab was assessed using the ACT-1 binding interference assay. ACT-1 is a mouse antibody similar to vedolizumab that also binds α4β7 integrin. The assay measures the percentage of cells bearing α4β7 that were not saturated with vedolizumab at the time of sampling.

The target of vedolizumab is α4β7 integrin, a receptor found on inflammatory immune cells that guides these inflammatory cells to the gut and binds to the mucosal address in cell adhesion molecule-1 (MAdCAM-1) on gut endothelial cells. The extent of the α4β7 receptor saturation by vedolizumab was assessed using the MAdCAM-1-Fc binding interference assay at time points where at least 50% of participants in the analysis set had non-missing results. MAdCAM-1-Fc is a fusion of human MAdCAM-1 with parts of a mouse monoclonal antibody. The assay measures the percentage of cells bearing α4β7 that were not saturated with vedolizumab at the time of sampling.