PHAT Stock Eyes Worst Day In Nearly Two Years After Generic Drug Maker Challenges Key Drug’s Exclusivity

• BDR is principally challenging the FDA’s alleged refusal to accept an abbreviated new drug application referencing Phathom’s new drug application for VOQUEZNA tablets. 
• Phathom said it is reviewing BDR’s filings but believes the FDA carefully and correctly evaluated the issue when it recognized the drug’s exclusivity until 2032. 
• The company stated it “intends to take appropriate action to protect its statutory exclusivities.”

Shares of Phathom Pharmaceuticals (PHAT) plunged roughly 23% on Friday after the company disclosed that BDR Pharmaceuticals had sued the U.S. Food and Drug Administration over exclusivity for its key drug VOQUEZNA.

Phathom said BDR Pharmaceuticals International Pvt. Ltd. filed suit in the U.S. District Court for the District of Columbia against the FDA and related federal defendants. BDR is principally challenging the FDA’s alleged refusal to accept an abbreviated new drug application (ANDA)—the pathway for a generic version—referencing Phathom’s new drug application for VOQUEZNA tablets.

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BDR claims the FDA improperly applied laws to extend Phathom’s drug’s exclusivity. The stock is now on track for its worst day since November 2024, if the losses hold.

VOQUEZNA Market And Exclusivity

VOQUEZNA is used for heartburn related to non-erosive gastroesophageal reflux disease (GERD), healing and maintenance of erosive GERD, and as a combination for H. pylori infection. The drug was first approved in May 2022 and later for other indications. The drug carries 10 years of exclusivity and protection against generic versions, until May 2032.

Phathom said it is reviewing BDR’s filings but believes the FDA carefully and correctly evaluated the issue when it recognized the drug’s exclusivity until 2032. The company stated it “intends to take appropriate action to protect its statutory exclusivities.” An adverse outcome could shorten exclusivity, allow earlier ANDA acceptance and potential approval, and pressure VOQUEZNA sales, the stock price, and overall business prospects.

Wall Street Weighs In On PHAT

Cantor Fitzgerald acknowledged that ongoing lawsuits can create overhangs for stocks. However, the firm sees a low likelihood that the FDA will reverse its decision and estimates Phathom still has more than six years of selling VOQUEZNA without competition. Cantor maintained its ‘Overweight’ rating on the shares.

Phathom Pharmaceuticals reported $175.1 million in net revenue for full-year 2025. This was a 217% increase from $55.3 million in 2024, and essentially all came from sales of its VOQUEZNA franchise.

How Did PHAT Retail Traders React?

On Stocktwits, retail sentiment around PHAT stock jumped from 'bearish' to 'extremely bullish' territory over the past 24 hours, while message volume rose from 'low' to 'extremely high' levels.

A Stocktwits user highlighted that the lawsuit is not confirmation of generic competition.

Another user said that the lawsuit will have little impact besides causing the selloff, as the FDA will not allow generics for the drug.

PHAT stock has dropped 67% year-to-date. 

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