* Expects Q2 rev $7.9 mln to $8.4 mln vs est $9.01 mln
* Shares down 13 pct after market
July 23 (Reuters) - Zogenix Inc estimated second-quarter net revenue below market expectations, sending its shares down 13 percent after the bell.
The company said in a regulatory filing that it expects revenue to be in the range of $7.9 million to $8.4 million for the second quarter.
Analysts were expecting revenue of $9 million, according to Thomson Reuters I/B/E/S.
Zogenix also said it did not receive any contract revenue for the second quarter due to the termination of a co-promotion agreement for its acute migraine treatment with the U.S. subsidiary of Astellas Pharma.
The company earned contract revenue of $8.5 million in the first quarter of 2012 including milestone payments from Astellas. It received contract revenue of $1.6 million in the first quarter of 2011.
Shares of the San Diego, California-based company were trading at $1.85 after the bell. They closed at $2.12 on Monday on the Nasdaq.