Horizon Therapeutics (HZNP) said Tuesday it's considering potential offers from three Big Pharma stalwarts, sending HZNP stock soaring more than 30% after hours. The board is engaged in "highly preliminary discussions" with Amgen (AMGN), Johnson & Johnson's (JNJ) Janssen division and Sanofi (SNY). There is no guarantee an offer will come to fruition, Horizon said in a news release. Each of the suitors is required to announce an offer by no later than Jan. 10 in accordance with Irish Takeover Rules. Horizon is headquartered in Dublin, Ireland. In after-hours trading on today's stock market, HZNP stock roared 32.1% higher, trading near 104. HZNP Stock: Tepezza Sales Topple Horizon's biggest product is Tepezza, a treatment for thyroid eye disease. In the September quarter, Tepezza sales toppled 20% to $490.9 million. But that beat expectations for $486.7 million, according to FactSet. Tepezza sales fell due to supply chain challenges amid the Covid pandemic. But the biotech company reiterated its expectations for Tepezza sales to grow by a high-teens percentage this year. Horizon expects global annual sales of the drug to peak at $4 billion. Total sales also topped expectations at $925.5 million. Adjusted profit of $1.25 per share was well above HZNP stock analyst forecasts. YOU MAY ALSO LIKE: More