* AstraZeneca confirms talks with biotech firm Acerta
* Signals determination to build up cancer drug business
* "No certainty" that any deal will be agreed (Adds comment on other potential bidders for Acerta)
By Ben Hirschler
LONDON, Dec 14 (Reuters) - AstraZeneca said on Monday it was in talks that might lead to the acquisition of privately held biotech firm Acerta Pharma, a potential $5 billion-plus deal designed to build up its cancer drug portfolio.
"AstraZeneca confirms that it is exploring potential strategic options with Acerta Pharma BV. There can be no certainty that any transaction will ultimately be entered into, or as to the terms of any transaction," it said in a brief statement.
Credit Suisse analysts said acalabrutinib's considerable potential could also encourage other potential buyers. "If Acerta is open to a transaction, we would expect significant interest from multiple other bidders," they said in a note.
The Wall Street Journal had reported on Friday that the British drugmaker was looking to buy Acerta for more than $5 billion to gain access to its experimental blood cancer drug acalabrutinib.
Acalabrutinib works in a similar way to Imbruvica, which was developed by Pharmacyclics but is now controlled by AbbVie after the U.S. drugmaker bought Pharmacyclics for $21 billion earlier this year. Johnson & Johnson jointly markets Imbruvica.
Both drugs are so-called Burton's tyrosine kinase inhibitors that target an array of blood cancers and have the potential to become multibillion-dollar-a-year sellers, according to industry analysts. They may also help in autoimmune diseases like lupus.
Given pharmaceutical companies' current heated interest in oncology, Bernstein analyst Tim Anderson said it was not surprising that Acerta, based in California and the Netherlands, was an acquisition candidate.
PIPELINE BOOST
Acerta does not yet have a partner to help develop its leading drug, although it has agreed to test acalabrutinib in combination with Merck's Keytruda.
Acerta is running a wide range of cancer clinical trials, including two final-stage Phase III studies. Last week it reported positive results in leukaemia.
The decision to chase after Acerta reflects a determination by AstraZeneca Chief Executive Pascal Soriot to use deals to boost his company's pipeline as sales of older blockbusters, including cholesterol fighter Crestor, lose patent protection.
Last month he agreed to buy ZS Pharma, a specialist in treating high potassium levels, for $2.7 billion.
The biggest hopes are pinned on oncology, however, where AstraZeneca already has a goal of bringing six new cancer treatments to market by 2020.