One of the top ranked drug manufacturers, AstraZeneca, has pulled American and European regulatory submissions for its much talked about lung cancer medicine Zactima. Along with chemotherapy, the drug is being touted as an effective treatment for lung cancer.

In June, AstraZeneca had filed the new drug as a potential treatment for large cell lung cancer which was in its advanced stages. Filed with the American and European authorities, these submissions touted Zactima as one of the most important new 2009 submissions.

The decision to yank the previously filed submissions, which had managed to garner much attention, came after an updated clinical study by regulators which put forward findings that revealed that there were, overall, no improvements as such to a patient's survival chances when Zactima, or Vandetanib, was complimented with chemotherapy.

Regulators have also warned the company that its current clinical data might not be enough for a complete approval, and it should conduct further tests and present more concrete data for Zactima.