The blockbuster medicine for diabetes clocked annual sales of over $1 billion in the US alone. Ranbaxy is known to be the first one to have challenged the patent of Actos and expects a six-month marketing exclusivity in the US.

Actos is the money-spinning drug of Takeda, Japan's largest pharmaceutical company. What makes the possibility of an out-of-court settlement interesting is the fact that the soon-to-be owners of Ranbaxy, Daiichi Sankyo, is Japan's second largest drug maker. Incidentally, Ranbaxy is believed to be derisking its businesses at Daiichi's behest.

With the Lipitor litigation settled, Actos is perhaps the only remaining blockbuster drug, whose patent has been challenged by Ranbaxy. The other patent-related litigations, apart from the five pending Lipitor litigations Ranbaxy has with Pfizer in Europe, are on drugs like Allegra, Valcyte and Provigil. While the litigation on Allegra is with Sanofi Aventis, it is locked in a legal battle with Roche over Valcyte.

In the case of Provigil, Ranbaxy has been sued by Apotex for allegedly engaging in anti-competitive collusion with the patent holder and delaying the entry of generic medicines in the US market. The combined sales of these medicines in the US could be just over $1 billion, analysts said.

"Wherever there is a ligitation outstanding, Ranbaxy is sure to go for settlements. Daiichi, being an innovator company, may not like its subsidiary engaging in patent infringement allegations," analysts said.

 Declining to provide details of Ranbaxy's pending litigations, a company spokesperson said, "Ranbaxy is open to settlement opportunities and considers these on a case-to-case basis. Our objective is to make affordable drugs available and maximise shareholder value."

In the past, Ranbaxy has said it has one of the largest product pipelines in the US, which include 18 first-to-file opportunities with a significant market size of over $27 billion at innovator prices.

While the company had been aggressive in fighting legal battles earlier, since the last year, it has started seeing huge business potential in out-of-court settlements.

Including Lipitor, Ranbaxy has made five settlements since 2007. This includes three independent litigation settlements with innovator companies GlaxoSmithKline (GSK) for Valacyclovir (Valtrex) and Sumatriptan (Imitrex) and with Boehringer Ingelheim/Astellas Pharma for Tamsulosin (Flomax).

These products have a combined market size in excess of $3.5 billion (at innovator prices). Ranbaxy will be launching these products in 2008 (Sumatriptan), 2009 (Valacyclovir) and 2010 (Tamsulosin) on an exclusive basis.

In April 2008, Ranbaxy entered into a settlement with AstraZeneca on the world's second largest selling molecule, Nexium (Esomeprazole), having a market size of around $5.5 billion.

The settlement will allow Ranbaxy to commence exclusive sales of a generic version of Nexium under a licence from AstraZeneca on May 27, 2014. During the 180-day period following the date, Ranbaxy will distribute the only generic Esomeprazole magnesium product in the US market.

The most recent one was the last week's settlement with Pfizer on Lipitor, which has $8 billion sales in the US alone.

With a majority of its patent ligitations settled, Ranbaxy could expect a revenue upside of approximately $3 billion over the next 6 to 10 years, analysts said.