Company: PHAT
Filing Date: 2025-03-06
Form Type: 10-K
Source: 0000950170-25-034183
Chunk: 30

Company: Phathom Pharmaceuticals, Inc.
Filing Date: 2025-03-06
Form: 10-K
Item: Item 1
Chunk 30
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itory concentration of antibiotic required to eradicate 90% of H. pylori in vitro, or MIC90. As pH increases, the amount of antibiotic required for 90% eradication decreases substantially. 

23

H. pylori MIC90 Values as a Function of pH

A triple therapy regimen (PPI, clarithromycin, and either amoxicillin or metronidazole) is the regimen most commonly used in clinical practice for the first-line treatment of H. pylori infection. However, H. pylori eradication rates with PPI triple therapy in the 1990s have fallen to current levels of <80%, primarily due to increased resistance of H. pylori to clarithromycin and metronidazole. A recent meta-analysis indicates that U.S. resistance rates measured from 2012 to 2016 were 20% for clarithromycin, 29% for metronidazole, and 19% for levofloxacin. Additionally, in a U.S.-based study from 2021, 65.6% of tested H. pylori was resistant to at least one antibiotic currently used for treatment, with resistance rates of 33% for clarithromycin and approximately 30% for metronidazole and levofloxacin. These figures represent a marked increase from 2009 to 2011 for both clarithromycin and metronidazole, for which resistance was 9% for clarithromycin, 21% for metronidazole, and 11% for levofloxacin. H. pylori resistance to amoxicillin remains low despite its use in most triple therapy regimens; resistance is generally <2% among isolates in the United States and Europe. There is a similar trend of increasing resistance to key antibiotics in Europe.

Given the declining eradication rates for H. pylori, bismuth quadruple therapy is recommended as first-line treatment; however, our U.S. market research study reported that physicians prescribe quadruple therapy to only 17% of first-line patients. Due predominantly to considerations of convenience and patient compliance, approximately 75% of physicians surveyed in our market research expressed a preference for convenience, or combination packs compared to individual bottles for both dual and triple therapy. Further, geographic patterns of resistance in the United States are poorly understood and treatment is largely empiric, with susceptibility testing rarely conducted prior to first-line treatment. Our U.S. market research study reported that only 8% and