Core Insights - CorMedix (CRMD) and Mirum Pharmaceuticals (MIRM) attract investors in the rare-disease biotech sector due to smaller patient populations that can yield significant revenue through premium pricing and regulatory incentives [1] - Both companies benefit from clearer clinical endpoints and faster regulatory pathways, allowing quicker market entry compared to traditional drugs [1] CorMedix (CRMD) Overview - CorMedix's lead product, DefenCath, received FDA approval in late 2023 as the first antimicrobial catheter lock solution in the U.S., aimed at reducing catheter-related bloodstream infections in kidney failure patients [2] - DefenCath generated $167.6 million in net sales in the first nine months of 2025, indicating strong market adoption [7] - The company plans to expand DefenCath's label into total parenteral nutrition and has diversified its revenue through a $300 million acquisition of Melinta Therapeutics, adding seven approved therapies to its portfolio [7] - Despite initial success, CorMedix's future outlook is cautious, with 2026 revenue guidance of $300-$320 million and projected 2027 revenues of $100-$140 million, reflecting pricing pressures and limited growth [8][11] Mirum Pharmaceuticals (MIRM) Overview - Mirum's lead product, Livmarli, is approved for treating cholestatic pruritus in patients with Alagille syndrome and has seen a 70% year-over-year increase in net sales, reaching $161.4 million in the first nine months of 2025 [3][12] - The company has expanded its portfolio with a new tablet formulation of Livmarli and additional bile acid products from the acquisition of Travere Therapeutics, generating $118.8 million in the first nine months of 2025 [16] - MIRM's revenue guidance for 2026 is approximately $630-$650 million, supported by a broader product base and ongoing clinical studies for new therapies [16][28] Comparative Analysis - Both companies exhibit a similar risk-reward profile, but MIRM presents a clearer growth narrative with multiple revenue drivers, while CRMD's outlook is clouded by conservative guidance and reliance on a single product [4][9] - MIRM's shares have increased by 75.3% over the past six months, contrasting with CRMD's 38% decline, indicating market preference for MIRM's growth potential [23] - Valuation metrics show MIRM trading at a price/book ratio of 16.02, significantly higher than CRMD's 1.43, reflecting investor confidence in MIRM's growth prospects [24] Investment Recommendation - Mirum Pharmaceuticals is viewed as the better investment opportunity due to its strong sales growth, diversified revenue streams, and multiple growth levers, while CorMedix faces more uncertainty and competitive pressures [25][29]