Johnson & Johnson Reportedly in Talks to Acquire Protagonist Therapeutics

Johnson & Johnson (NYSE: JNJ) is in discussions to acquire Protagonist Therapeutics, Inc. (NASDAQ: PTGX), according to reports from The Wall Street Journal and Reuters. The potential acquisition would expand Johnson & Johnson’s pipeline in oncology and immune-mediated diseases, while deepening its existing partnership with Protagonist.

While terms have not been finalized, people familiar with the matter said the deal could value Protagonist above its current market capitalization of approximately $4.2 billion. Shares of Protagonist rose more than 30% in afternoon trading following the news.

Johnson & Johnson currently holds an estimated 4% stake in Protagonist and has been collaborating with the company on the development of icotrokinra, an oral therapy targeting plaque psoriasis and ulcerative colitis. Under existing agreements, J&J holds exclusive commercialization rights to the program.

The acquisition would also grant J&J access to rusfertide, a late-stage therapeutic candidate for polycythaemia vera, a rare blood disorder. Rusfertide is being developed in partnership between Protagonist and Takeda Pharmaceutical Company Limited (TSE: 4502) and has demonstrated strong clinical results in recent trials.

If completed, the transaction would strengthen J&J’s oncology and immunology portfolios at a time when the company faces upcoming patent expirations for its top-selling immune-disease drug Stelara. Analysts said the deal would be financially manageable for Johnson & Johnson, which has a market capitalization approaching $460 billion.

The company has pursued an active acquisition strategy to bolster its innovative medicine division. In January 2025, Johnson & Johnson acquired Intra-Cellular Therapies in a $15 billion transaction, and in 2024, it purchased Proteologix for approximately $850 million to expand its immunology research capabilities. In March 2025, J&J Innovative Medicine announced plans to invest up to $55 billion in U.S. expansion projects through 2029.

Since its 2016 initial public offering, Protagonist Therapeutics’ shares have risen more than 450%, driven by clinical advancements in peptide-based therapeutics targeting hematologic and inflammatory conditions.

Both companies declined to comment on the ongoing discussions, according to Reuters.

About Johnson & Johnson

Johnson & Johnson (NYSE: JNJ) is a global healthcare company engaged in the research, development, manufacture, and sale of products in the pharmaceutical, medical technology, and consumer health sectors. Headquartered in New Brunswick, New Jersey, Johnson & Johnson operates in more than 60 countries and serves more than one billion patients worldwide.

About Protagonist Therapeutics

Protagonist Therapeutics, Inc. (NASDAQ: PTGX) is a biopharmaceutical company focused on discovering and developing peptide-based drugs to address unmet medical needs in hematology and immunology. The company’s lead candidates include rusfertide for polycythaemia vera and icotrokinra for immune-mediated diseases. Protagonist is headquartered in Newark, California.

At the time of publishing, Stocks.News holds positions in Johnson and Johnson as mentioned in the article.