AstraZeneca has confirmed speculation that it is “exploring potential strategic options” with Acerta Pharma, a privately owned biotech firm with operations in the Netherlands and California.

However, the British-Swedish drugmaker said, “there can be no certainty that any transaction will ultimately be entered into, or as to the terms of any transaction.” It added it would make a further announcement “if and when appropriate.”

Earlier, the US newspaper Wall Street Journal had reported that AstraZeneca had offered to buy Acerta for more than $5 billion to gain access to its experimental blood cancer drug acalabrutinib.

Acerta is currently developing acalabrutinib, also known as ACP-196, for the treatment of various malignancies, including leukemias and lymphomas. Data from recent Phase I/II trials is said to have shown that the Bruton tyrosine kinase (BTK) inhibitor was associated with a response rate of 95% among patients with relapsed chronic lymphocytic leukemia.

Acalabrutinib is said to work in a similar way to Imbruvica, developed by Pharmacyclics. That company was snapped up for $21 billion earlier this year by AbbVie, which currently co-markets the drug with Johnson & Johnson.

Both products target a variety of blood cancers and are regarded as having the potential to become multibillion-dollar-a-year blockbusters, especially as they may also help treat autoimmune diseases such as lupus.