European drugs regulators have approved AstraZeneca's new thyroid cancer pill vandetanib, or Caprelsa, giving a boost to a drug which has suffered a series of recent setbacks.

The Anglo-Swedish drugmaker said in a statement on Friday its application for a marketing authorisation for Caprelsa received a positive opinion from the European Medicines Agency for the treatment of advanced and non-operable medullary thyroid cancer.

Vandetanib was once seen as a potential $1 billion (631 million pounds)-plus blockbuster for AstraZeneca, but suffered a major setback after failing to extend survival in patients with lung cancer.

U.S. drugs regulators delayed a decision on whether to approve the drug in January, saying they needed more time to review the medicine.

The drug is now targeted at the niche market of treating patients with non-operable advanced medullary thyroid cancer (MTC), which accounts for about 4 percent of thyroid cancers.

(Editing by Mike Nesbit)