The efficacy of IQIRVO was evaluated in Study 1 (NCT04526665), a multi-center, randomized, double-blind, placebo-controlled study. The study included 161 adults with PBC with an inadequate response or intolerance to UDCA. Patients were randomized to receive IQIRVO 80 mg (n=108) or placebo (n=53) once daily for at least 52 weeks. When applicable, patients continued their pre-study dose of UDCA throughout the study. Patients were included in the study if their ALP was greater than or equal to 1.67-times the ULN and TB was less than or equal to 2-times the ULN. Patients were excluded if they had other liver disease or in case of decompensated cirrhosis.
The mean age of patients in Study 1 was 57 (Range: 36, 76) years, and the mean weight was 70.8 (Range: 43, 134) kg. The study population was predominately female (96%) and White (91%). The baseline mean ALP concentration was 321.9 (Range: 151, 1398) U/L, and 39% of patients had a baseline ALP concentration greater than 3-times the ULN.
The mean baseline TB concentration was 0.56 (Range: 0.15, 1.76) mg/dL, and 96% of patients had a baseline TB concentration less than or equal to ULN. The baseline mean concentration of ALT was 50 (Range: 11 to 188) U/L and mean baseline concentration for AST was 46 (Range: 14 to 203) U/L.
Most patients (95%) received study treatment (IQIRVO or placebo) in combination with UDCA. There were 6 (6%) in the IQIRVO-treated patients and 2 (4%) in the placebo-treated patients who were unable to tolerate UDCA and received IQIRVO as monotherapy. At baseline, 12 (11%) of the IQIRVO-treated patients and 8 (15%) of the placebo-treated patients met at least one of the following criteria: serum albumin < 3.5g/dL, INR >1.3, TB > 1-time ULN, Fibroscan >16.9 kPa, or historical biopsy suggestive of cirrhosis.
The primary endpoint was biochemical response at Week 52, where biochemical response was defined as achieving ALP less than 1.67-times ULN, TB less than or equal to ULN, and ALP decrease greater than or equal to 15% from baseline. The ULN for ALP was defined as 129 U/L for males and 104 U/L for females. The ULN for TB was defined as 1.20 mg/dL. ALP normalization (i.e., ALP less than or equal to ULN) at Week 52 was a key secondary endpoint.
Table 6 presents results at Week 52 for the percentage of patients who achieved biochemical response, achieved each component of biochemical response, and achieved ALP normalization. IQIRVO demonstrated greater improvement on biochemical response and ALP normalization at Week 52 compared to placebo. Overall, 96% of patients had a baseline TB concentration less than or equal to ULN. Therefore, improvement in ALP was the main contributor to the biochemical response rate results at Week 52.
Figure 1 depicts the mean (95% confidence interval) ALP levels over 52 weeks. There was a trend of lower ALP in the IQIRVO group compared to the placebo group starting by Week 4 through Week 52.
Figure 1: Mean ALP (+/- 95% Confidence Interval) in Adult Patients with PBC Over 52 Weeks in Study 1

Missing data and data following study treatment discontinuation was imputed by multiple imputation.