Phathom Pharmaceuticals Inc. will begin marketing Voquezna (vonoprazan) in December, thanks to the Nov. 1 approval by U.S. regulators, who cleared the potassium-competitive acid blocker at 10-mg and 20-mg doses for all grades of erosive gastroesophageal reflux disease (GERD), maintenance of healing of all grades of the condition and relief of associated heartburn.