PHAT - Phathom falls 22% in in after-hours trading on FDA formal request for vonoprazan data

• Phathom Pharmaceuticals ( NASDAQ: PHAT ) said it has received correspondence from the US FDA formally asking for additional stability data from the company's vonoprazan products.
• The data is to assure the agency that levels of a nitrosamine impurity, N-nitroso-vonoprazan (NVP), previously found in commercial batches, will be at or below daily acceptable intake throughout the drug's shelf life.
• The stock is down 22% in after-hours trading.
• In August 2022, Phathom ( PHAT ) found trace amounts of NVP in commercial batches of the drug. Since then, it has been working with the FDA on an acceptable daily intake limit and ways to control the impurity prior to vonoprazan hitting the market.
• The company had planned on launching vonoprozan combination antibiotic products under the names Voquezna Double Pak and Voquezna Triple Pak in Q3 2022.
• In January, the FDA delayed a decision on vonoprozan for another indication, erosive esophagitis .

For further details see: