What happened

Shares of Bellus Health (BLU) jumped 105.1% this week as of Thursday afternoon, according to data provided by S&P Global Market Intelligence. The company, which received a $2 billion buyout offer from GSK (formerly known as GlaxoSmithKline) (GSK -1.25%), closed at $7.06 last week and reached a new 52-week high at $14.50 on Tuesday. The biotech stock is up more than 76% so far this year.

So what

The stock could easily go higher, because GSK's offer was for $14.75 a share. The attraction for GSK is camlipixant, Bellus' late-stage pipeline candidate to treat adults with refractory chronic cough (RCC). That's a cough that continues for more than eight weeks despite treatment, and in some cases, it might not have an identifiable cause.

The oral therapy, a P2X3 antagonist, is in two phase 3 trials to treat RCC, and the results are expected in the second half of 2024 and 2025. Bellus said it anticipates launching the drug in 2026, pending regulatory approval. According to company data, 28 million patients suffer from chronic cough, with 10 million patients globally and 6 million in the United States (U.S.) and the European Union (EU) suffering from RCC for more than a year.

Now what

Bellus' stockholders need to vote on the offer, and the deal is expected to be approved by the third quarter of 2023. GSK's own stock has fallen about 3% over the past week.

The addition of camlipixant would give GSK strong competition to gefapixant, a P2X3 receptor antagonist to treat RCC that is being developed by Merck (MRK 0.28%). That therapy has been approved in Japan but is in the process of responding to a Food and Drug Administration complete response letter in the U.S.

Bellus has no marketed drugs yet, and as of December 31, 2022, it said it had $337.1 million in cash, up from $248.8 at the end of 2021. The company had very little revenue and lost $76.1 million in 2022.