Paratek shares bounce after matching Pfizer in antibiotic study


Paratek Pharmaceuticals ($PRTK) saw its shares jump by more than 23% in afterhours trading as it posted new Phase III data for its antibiotic omadacycline--with just one more trial to go before it can file with regulators.

The Boston, MA-based biotech was studying the drug in patients with acute bacterial skin and skin structure infections (ABSSSI).

Oral and injectable versions of once-daily omadacycline were being tested against the twice-daily treatment from Pfizer ($PFE), known as Zyvox (linezolid), which has a license for infections caused by Gram-positive bacteria that are resistant to other antibiotics. Paratek’s drug achieved non-inferiority in the study (i.e., it was clinically as good as Zyvox).

Although not besting Pfizer’s treatment, it still met the regulators' standard for the trial--hitting an early clinical response--and so the company can chalk this up as a win.

The drug was being tested over a 1-2 week course in 645 patients with early clinical response rate for Paratek and Pfizer being 84.8% and 85.5%, respectively. Secondary endpoints have not yet been published--but will be later this year, according to the biotech.

Another Phase III trial is also expected to post data later this year, with both studies together designed to aid EMA and FDA approvals.

Omadacycline, a tetracycline antibiotic known as an aminomethylcycline, has broad spectrum activity against Gram-positive, Gram-negative and atypical bacteria. These are the types of resistant bacteria that have been grabbing headlines in recent years, prompting governments around the world to encourage biopharma companies to do more to develop new and better antibiotics.

“The successful achievement of these primary efficacy and secondary outcomes, combined with the safety and tolerability outcomes for both the oral and IV formulations of omadacycline is a significant step towards securing regulatory approval and advancing omadacycline to commercialization,” said Michael Bigham, chairman and CEO of Paratek.

“Increasingly, patients and physicians are faced with the growing challenge that existing antibiotic therapies are failing as pathogens develop resistance. The positive data from this registration study demonstrate the clear potential of omadacycline to treat serious community-acquired infections where resistance is of concern.”

The company has an odd history, failing in its first attempt at an IPO back in 2012 and then only going public through a reverse merger with Transept two years’ ago. Bayer, Merck ($MRK) and Novartis ($NVS) have all at one time worked with the biotech on its drug, but have all since dropped out.

ABSSSI are responsible for more than 750,000 hospitalizations per year, representing a 17.3% increase in hospitalized ABSSSI patients from 2005 to 2011, according to estimates from Paratek.

There are already a number of drugs on the market for these infections, but most are narrowly focused and taken through an IV, whereas omadacycline is being developed both as an IV treatment and a daily pill, which could give it an edge in administration

As a broad spectrum drug, it can also deal with multiple types of infections--including gram-negative bacteria, the biotech is keen to point out. 

Many in Big Pharma have pulled out of antibiotic research in recent years, although Merck and Roche ($RHHBY) have tentatively picked up some new R&D projects in the area--but much of the grunt work is coming from biotech.

Just this week, Allecra raised $24.7 million to help it push on in Phase II trials for its antibiotic combo designed to treat drug-resistant Gram-negative bacterial infections. U.K.’s Redx Pharma and the new upstart Iterum are also among those looking to create a new set of antibiotics, and help stave off the “silent apocalypse” of antimicrobial resistance. 

-check out the release

Related Articles:
Fresh from a series B raise, Allecra looks to help stave off ‘antibiotic apocalypse’
Paratek absorbs the troubled Transcept in a reverse merger
Another startup jumps into antibiotics R&D as Iterum grabs a $40M round