Some behaviors come with inherent risks—such as feeding bears while camping, texting while driving, and investing in biotech stocks, which is often placed in the same category. However, not all biotech stocks carry extremely high risk. Mirum Pharmaceuticals (MIRM) is a rising star in this field, having successfully navigated the most dangerous phase for a small pharmaceutical company. Over the past 12 months, the company’s stock has risen more than 120%. Some believe that buying this biotech stock now could lay a solid foundation for future financial security.
Mirum currently has three therapies on the market. Livmarli is approved in the United States and Europe for the treatment of Alagille syndrome and progressive familial intrahepatic cholestasis, both rare inherited liver diseases. Ctexli is approved in the U.S. for the treatment of cerebrotendinous xanthomatosis, another rare metabolic disorder. Cholbam is approved in the U.S. for the treatment of bile acid synthesis disorders.
In the fourth quarter of 2025, the company’s net product sales grew 50% year-over-year. Livmarli performed particularly well, with sales surging 69% to $360 million. This strong growth enabled Mirum to achieve positive free cash flow in 2025. Although increased R&D spending this year will lead to negative free cash flow, the company’s management expects to quickly return to positive free cash flow in 2027.
Mirum plans to release key data from four clinical studies over the next 18 months. The first data is imminent: topline results from a Phase III study evaluating volixibat for primary sclerosing cholangitis are expected in the second quarter of 2026. In the second half of this year, the company will release Phase III data for brelovitug for hepatitis delta virus. In the fourth quarter, it plans to announce Phase III results for Livmarli in treating cholestatic pruritus. Additionally, the company expects to release topline results from a Phase III study of volixibat for primary biliary cholangitis in the first half of 2027.
The market estimates that the peak sales potential for Mirum’s pipeline exceeds $4 billion. The company’s current market capitalization is approximately $5.8 billion. Based on the average price-to-sales ratio of 6.4 times for biotech stocks, if its therapies reach their full potential, Mirum’s valuation could reach approximately $26 billion.
However, success for Mirum’s pipeline is not guaranteed. The opportunity for substantial returns always comes hand-in-hand with the risk of failure. It is not advisable to put all your capital into any single stock; building a diversified portfolio is essential.
Overall, Mirum has a relatively high likelihood of reporting positive results in its upcoming key studies. For this emerging biotech company, even a small amount of good news could lead to significant market performance.
