The U.S. health regulator has approved British drug maker BTG Plc's intravenous drug Voraxaze to treat harmful chemotherapy side effects relating to kidney failures in cancer patients.

The drug, also known as glucarpidase, helps reduce toxic levels of methotrexate, a commonly used chemotherapy drug used to treat breast, bone and lung cancer, by breaking it into a form that can be easily eliminated from the body.

"Voraxaze is an important new treatment option for cancer patients aimed at preventing these toxicities associated with sustained high levels of methotrexate," said Richard Pazdur, the head of the FDA's cancer drugs division.

The drug has an orphan drug status in both the U.S. and EU that ensures seven and ten years of marketing exclusivity in the respective countries.

Methotrexate is normally eliminated from the body by the kidneys itself. However, high doses of it can cause kidney failures and liver damages in patients receiving it. It can also damage the lining of the intestine and cause severe mouth sores, skin rashes and death due to low blood counts.

Currently, there are no other drug treatments available which are capable of reducing methotrexate levels.

A study involving 22 patients showed that methotrexate level fell below a critical level within 15 minutes of administering Voraxaze and stayed below that level for eight days. It was successful in eliminating 95 percent of the harmful chemical.

The most common side effects observed in the clinical study were low blood pressure, headache, nausea, vomiting, flushing and abnormal sensation.

Voraxaze was developed by Protherics, a Salt Lake, Utah-based drug maker that BTG acquired in 2008 for about $400 million. The company believes that Voraxaze could potentially be used as an adjunctive therapy with each cycle of high dose methotrexate therapy, an opportunity that could be worth more than $100m per annum.