Many bacteria have developed resistance to carbapenems and efforts to combine those last-line antibiotics with drugs to restore bacterial sensitivity have been unsuccessful. Rempex Pharmaceuticals Inc. has designed a beta lactamase inhibitor that restored carbapenem activity in preclinical models and could be effective against multi-drug resistant Gram-negative bacteria.

Carbapenems are broad-spectrum beta lactam antibiotics that kill Gram-positive and -negative bacteria by blocking cell wall synthesis. They are designed to avoid resistance mediated by bacterial beta lactamases, but some Gram-negative bacteria produce a variety of beta lactamases called carbapenemases that inactivate carbapenems.