Mirum’s volixibat achieves positive interim analyses

US liver disease focused biotech Mirum Pharmaceuticals (Nasdaq: MIRM) saw its shares leap 15.4% to $29.90 by close of trading on Monday, as it reported interim results from two Phase IIb studies evaluating volixibat, an oral ileal bile acid transporter (IBAT) inhibitor in patients with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC).

The California based company noted that interim results from the VANTAGE study evaluating volixibat in patients with PBC demonstrated a statistically significant (-3.82, p<0.0001) improvement in pruritus for volixibat and a placebo-adjusted difference of -2.32 points in the primary endpoint, p=0.0026, as measured by the Adult ItchRO scale. 75% of patients on volixibat achieved a greater than 50% reduction in serum bile acids. In addition, there was a significant improvement in fatigue at week 16 with volixibat compared to placebo.

No new safety signals were observed, and adverse events were similar between the 20mg and 80 mg treatment groups. The most common adverse event was diarrhea (77%) with all cases mild to moderate, and mostly transient; one case resulted in discontinuation. Four patients experienced serious adverse events, including one in the placebo arm. There were no clinically meaningful changes in liver biomarkers.