MUMBAI (Reuters) - India's patent appeals board has revoked a patent granted to GlaxoSmithKline Plc's (>> GlaxoSmithKline plc) breast cancer drug Tykerb, which is a salt form of the original compound, lapatinib.

However, the Intellectual Property Appellate Board (IPAB) upheld a patent granted to the original compound, or active pharmaceutical ingredient, citing innovative merit.

Fresenius Kabi Oncology (>> Fresenius Kabi Oncology Ltd), the Indian unit of German healthcare group Fresenius SE (>> Fresenius SE & Co KGaA), had challenged patents granted for both the original molecule and it's marketed version Tykerb, saying both molecules lacked innovation.

"We are studying the IPAB's decision but maintain our belief in the inventiveness of the lapatinib ditosylate salt and will consider the possibility of taking further steps before the appropriate authorities to validate this," the Indian unit of UK-based GSK said in an email to Reuters on Friday.

The IPAB orders for both the patent disputes were uploaded on its website late on Thursday.

(Reporting by Kaustubh Kulkarni; Editing by Tony Munroe)