The Indian arm of Swiss drug maker F Hoffman-La Roche Scientific has filed two separate petitions against Cipla in the Bombay high court alleging patent and trademark infringements over its anti-infection drug 'Valcyte'.

The first petition alleges that Cipla Ltd [Get Quote], India's second largest pharmaceutical company, violated Roche's patent by launching a generic version of Valcyte.

The second petition says Cipla violated the Swiss drug maker's trademark by launching the product in a phonetically similar name, 'Valcept'.

A generic is a drug that is chemically equivalent to an innovator's medicine and the drug is not protected by patent.

According to legal sources  tracking the development, the trademark infringement suit was filed last week and the case against alleged patent right violations early this week.

Roche officials confirmed the development but declined to provide more details. When contacted, Amar Lulla, joint managing director of Cipla, refused to comment.

This is the second product in which Roche and Cipla are locked in a legal battle on patent issues. The Delhi high court is expected to give its verdict on the first case -- involving Roche's cancer medicine Tarceva -- in two months.

Valcyte, which goes by the generic or chemical name 'Valganciclovir', is used to prevent eye infections for people with lower immune power. The medicine is also used for AIDS patients suffering from eye infections.

Civil society groups involved in helping AIDS patients had been at the forefront of opposing the Roche's patent application on Valganciclovir.

For technical reasons, the Chennai patent office had granted patent protection to Valganciclovir without hearing pre-grant oppositions, said NGOs involved in the case.

Indian pharma players and NGOs have filed a post-grant opposition against the decision. Cipla's product launch has come at a time when the patent office is considering the post-grant opposition.

Reacting to the development, Shamnad Basheer, a patent blogger, said the Mumbai high court may stay the proceedings until the post-grant opposition proceedings are completed.

"If the post-grant goes against Roche and the patent is invalidated, then the suit before the court becomes infructuous.

However, if the patent is upheld, the Bombay High Court can lift the stay and hear the injunction application afresh," Basheer said.

According to him, the trademark case could also be complicated as both the companies have derived the major portion of their brand names 'val'vyte and 'val'cept from the chemical name 'val'ganciclovir.

"Since 'val' is not a proprietary term but one that is derived from a chemical name, the courts are likely to hold that Cipla's Valcept does not infringe," he explained.