AstraZeneca has the option to buy the rest of Acerta — when the first approval of the cancer drug in the US and Europe has been gained — for about $3 billion.
Scientists believe that acalabrutinib, which is in the most advanced form of clinical trial, could have annual sales of more than $5 billion a year.
The British pharma company, which rejected a takeover bid from United States giant Pfizer last year, is seeking to rebuild its portfolio as many of its key drugs are no longer under patent.
In November, Astra agreed to buy ZS Pharma for $2.7 billion and this week snapped up lung cancer treatment specialist Takeda for $575 million.
