Mumbai: Swiss drug major Novartis AG has bought US-based vaccine maker Protez Pharmaceuticals in a deal worth up to $400 million, gaining rights to an antibiotic which could be used to fight superbugs such as MRSA.

"The acquisition of Protez Pharmaceuticals provides rights to PZ-601 and further strengthens specialty medicines development portfolio in hospital infections," Novartis said in a statement. Novartis will get rights to PZ-601 in the US and Europe.

PZ-601 is a novel broad-spectrum antibiotic in Phase II development against potentially deadly drug-resistant infections, including MRSA and ESBL strains, Novartis said.

Novartis will initially pay $100 million for privately held Protez, with a potential for up to $300 million in additional payments depending on the success of PZ-601, the company said.

PZ-601 is a new antibiotic in a class of agents known as carbapenems. Medicines in this class are useful in treating life-threatening infections caused by Gram-negative and Gram-positive bacteria. PZ-601, which is administered by injection, has been specifically shown to have a broad spectrum of activity that could offer better coverage over existing injectable antibiotics, especially against multidrug-resistant bacteria including MRSA (methicillin resistant Staphylococcus aureus) strains that are becoming an increasing public health challenge.

''Novartis has a long-standing commitment of bringing innovative medicines to severely ill patients and fighting infections that represent significant public health threats," said Joe Jimenez, CEO of Novartis Pharma AG. "The addition of Protez and its pipeline, including PZ-601, to our existing initiatives will further strengthen our position in the specialty field of hospital infections while helping to address the public health challenges of increasing bacterial resistance and high mortality rates."

Protez started a 100-patient, Phase II study in May 2008 in the US to evaluate the safety and efficacy of PZ-601 in patients with complicated skin and skin structure infections including cellulites, abscesses, infected wounds and ulcers. Novartis plans to start additional clinical trials for PZ-601, with the aim of first regulatory submissions in 2012.

Antibiotic resistance is one of the world's most pressing public health problems. According to the Centers for Disease Control and Prevention (CDC), two million people in the United States develop hospital-acquired infections each year, and approximately 90,000 die as a result. In Europe, an estimated three million hospital-acquired infections occur each year, resulting in some 50,000 deaths, the company said in its release.

The number of bacteria resistant to antibiotics has increased significantly in the last decade, including the potentially fatal type known as methicillin-resistant Staphylococcus aureus (MRSA) - or "staph" - branded as a major public health threat in many countries.

Bacteria have also been observed with resistance to other antibiotics, including hospital antibiotics such as vancomycin (VRE). In addition, officials have documented multidrug-resistant bacteria known as extended-spectrum beta-lactamase enterobacteriaceae (ESBL) that are considered to be an increasing public health threat.

The addition of PZ-601 further expands the Novartis portfolio of specialty medicines for severe infectious diseases, which already includes approved medicines as well as development compounds for use in treating hospital-based infections and hepatitis.

Protez will operate as a stand-alone subsidiary of Novartis, continuing its operations in Malvern, Pennsylvania.