UPDATE 1-Cubist to pay up to $1.62 bln for Trius, Optimer Pharma
* Says to pay $13.50 per share upfront for Trius
* Says to pay $10.75 per share upfront for Optimer
* Cubist shares up 3 pct after the bell
July 30 (Reuters) - Cubist Pharmaceuticals Inc said it would buy Trius Therapeutics Inc and Optimer Pharmaceuticals Inc for up to $1.62 billion as it seeks to strengthen its antibiotics portfolio.
Cubist said it would pay Optimer shareholders $10.75 per share in cash upfront, and an additional $5 per share contingent on Optimer meeting certain sales milestones.
The total value of $15.75 per share is a premium of about 19 percent to Optimer's Tuesday's closing price of $13.29, but represents a discount minus the contingent payment.
For Trius, Cubist will pay $13.50 per share in cash and another $2.00 per share if Trius meets certain sales targets. Collectively, the $15.50 per share offer, is about 32 percent more than Trius's Tuesday closing of $11.71.
Cubist, known for its Cubicin antibiotic, would gain a late-stage Trius drug that has shown promise in treating skin infections. From Optimer, Cubist will acquire the antibacterial, Dificid, which brought in sales of $19.0 million in the quarter ended June.
"I don't think (Cubist) will create a ton of value out of (the Optimer deal), but I don't think it's going to wind up looking like a bad deal," Baird analyst Brian Skorney said.
"The risk to me is that there is a little bit of overlap in terms of Trius' drug and Cubicin in terms of market opportunity in outpatient complicated skin infection," Skorney added.
Cubist shares rose about 3 percent to $58.50 after the bell. Trius shares were trading up at $13.75, while those of Optimer were down at $12.15 after hours.