Drugmaker Eli Lilly & Co. said Monday regulators have approved a longer-lasting version of its top-selling drug, the anti-psychotic Zyprexa.
The Food and Drug Administration approved Zyprexa Relprevv, an injection that can last up to four weeks, for the treatment of schizophrenia in adults.
Patients on Zyprexa currently take a pill daily. Lilly also makes a fast-acting injection of the drug that can be absorbed by the body in a few hours to treat agitation.
For the new version, patients will visit their doctors every two or four weeks _ depending on their dosage _ to receive the injection, spokeswoman Janell Smith said.
She said the longer-lasting version makes it easier for patients to stay on the medication, and it allows doctors to track whether they're doing that since they have to make office visits for the injections.
Zyprexa has been Lilly's top-selling drug for several years, and it rang up $4.7 billion in sales last year. But the anti-psychotic's sales have been flat this year, and its patent will expire in 2011, exposing it to generic competition.
Smith said the longer-lasting version of Zyprexa will have a separate patent, but she did not know when it expires.
Lilly shares rose 32 cents to $35.29 in Monday morning trading.