Report shows Pfizer's hand in Neurontin studies

* Internal documents show many studies not published

* Studies changed after the fact to show benefit-report

* Pfizer denies allegations; claims study is biased

By Julie Steenhuysen

CHICAGO, Nov 11 (Reuters) - A study of internal company documents suggests Pfizer Inc (PFE.N) altered or omitted unfavorable study findings to expand its epilepsy drug Neurontin's market, U.S. researchers said on Wednesday, offering a look at how drugmakers influence scientific research.

Clinical trials are supposed to answer a specific, predetermined scientific question, but a comparison of Pfizer documents and published studies on Neurontin for conditions other than epilepsy found that eight out of 20 study reports never made it into medical journals.

And in eight of the 12 published studies, the primary outcome -- the answer to the main scientific question -- was changed by Pfizer, the world's biggest drugmaker, from the original study design.

"There were a lot of primary outcomes that were shifted around between the planning of the protocol and the reporting of the study," said Kay Dickersin of Johns Hopkins University in Baltimore, whose study appears in the New England Journal of Medicine.

"Some primary outcomes were lost altogether. Some were brand new. Some were secondary outcomes that were upgraded to primary," she said in a telephone interview.