Antibiotic - PTK 0796
The growing incidence of bacteria that are resistant to current antibiotics means there is a great need for new drugs that retain activity against them. One such novel antibiotic, PTK 0796 or amadacycline, is being developed by US company Paratek Pharmaceuticals.1 Based on its tetracycline platform, it is a broad spectrum antibiotic that is being developed for first line use in hospital infections, including those caused by multidrug resistant bacteria.
The growing incidence of bacteria that are resistant to current antibiotics means there is a great need for new drugs that retain activity against them. One such novel antibiotic, PTK 0796 or amadacycline, is being developed by US company Paratek Pharmaceuticals.1 Based on its tetracycline platform, it is a broad spectrum antibiotic that is being developed for first line use in hospital infections, including those caused by multidrug resistant bacteria.
The first in class drug is an aminomethylcycline, and is predicted to lack the drug resistance of existing tetracyclines. Both intravenous and oral forms are being investigated. In the lab, it was found to be active against a broad range of bacteria, both Gram positive and Gram negative.2 These included methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant Enterococcus faecium, and Haemophilus influenzae.
A Phase II trial in patients with complicated skin and skin structure infections was recently reported.3 A total of 219 subjects were given 100mg of the drug intravenously once a day to start with followed by 200mg oral doses once a day, or twice daily 600mg intravenous doses of linezolid followed by 600mg oral doses twice a day. The clinical success rates for the two drugs were 88% and 76% respectively. There were two failures in the amadacycline group, neither of which was associated with MRSA, whereas two of the four failures in those given linezolid were MRSA related.
The two drugs had similar efficacy against MSSA. Similar side-effect profiles were seen in both treatment groups: the most common were gastrointestinal problems, and for amadacycline these were almost all associated with oral therapy. No serious drug related adverse events were observed.