With Fresh Pneumonia Data, Paratek To Seek 2018 Antibiotic Approval

Xconomy Boston — 

The need for new antibiotics to battle drug-resistant bacteria is rising, and Paratek Pharmaceuticals has news that could give doctors a new weapon.

Boston-based Paratek (NASDAQ: PRTK) reports that its antibiotic, omadacycline, has hit all its main and secondary goals in a study of 774 patients with hospital-acquired pneumonia. It is the second of two trials; last year, Paratek’s antibiotic succeeded in a study of 645 patients with certain types of bacterial skin infections.

Omadacycline is being developed both as an IV treatment and once-a-day pill, which would allow patients to continue taking the drug once discharged from the hospital. It’s a broad-spectrum antibiotic, meaning it can handle multiple types of infections. With the new data, Paratek plans to file for approval of omadacycline in the U.S. by the first quarter of 2018 and in Europe later next year.

Shares of Paratek surged more than 42 percent in after-hours trading on Monday.

The 774-patient pneumonia study, OPTIC, compared the IV-oral combination of omadacycline to treatment with a current standard of care, a similar IV-oral combination of the antibiotic moxifloxacin.

The main goal of the study was for omadacycline to perform at least comparably to—not necessarily better than—moxifloxacin to help patients achieve an “early clinical response,” or improvement in symptoms like chest pain and difficulty breathing three to five days after their first dose. The early clinical response rate for omadacycline was 81.1 percent, compared to 82.7 percent for moxifloxacin. Paratek’s threshold for success was for omadacycline to be within 10 percent of moxifloxacin.

Secondary goals, which omadacycline also hit, included response rates five to 10 days after treatment was completed (87.6 percent for omadacycline, 85.1 percent for moxifloxacin).

The most common side effects were high blood pressure, nausea, vomiting, and an increase in liver enzymes, though the rates of each were comparable between omadacycline and moxifloxacin and in some cases lower with Paratek’s drug. There were more treatment-related side effects for patients on moxifloxacin (48.5 percent of patients) than omadacycline (41.1 percent). Paratek will discuss more details at a future medical meeting.

Pneumonia is a leading cost of hospitalization in the U.S., with medical costs exceeding $10 billion in 2011, according to a study from the Healthcare Cost and Utilization Project, a collection of health databases associated with the U.S. Department of Health and Human Services. In 2015 the Centers for Disease Control and Prevention reported that 14 percent of roughly 2,300 pneumonia cases in U.S. adults were caused by bacterial infections like Streptococcus pneumonia and Staphylococcus aureus.

Drug-resistant bugs are on the rise. According to the CDC, 2 million Americans each year suffer from drug-resistant bacterial infections, and more than 23,000 of them die. Antibiotics, many of them cheap and generic, are available for bacterial pneumonia infections, but new additions are sorely needed—particularly in light of clinical failures and regulatory setbacks over the past couple years from companies like Cempra (NASDAQ: CEMP) and Tetraphase Pharmaceuticals (NASDAQ: TTPH).

Paratek president, chief operating officer, and chief medical officer Evan Loh says that many of the bugs associated with bacterial pneumonia are becoming resistant to currently available antibiotics, among them the cheap generics.

“Bugs always win,” says Loh. “This is an area where if you don’t introduce new technology every 10 to 15 years, you run into a place where resistance leads to complete obsolescence of currently available antibiotics.”

Another problem is that the class of antibiotics known as quinolones, like moxifloxacin, are associated with safety problems.

Even with recent initiatives to spur antibiotics R&D such as the GAIN Act in 2012, and more clarity from regulators regarding clinical trial design than before, companies can’t charge the high prices they feel are justified. “The value of antibiotics is underappreciated,” Loh argues, pointing out that some cancer therapies can get a “huge premium” for extending lives for weeks or months, whereas antibiotics don’t command those prices but can actually save lives. That environment is something Paratek will likely have to battle through. Leerink Partners analysts have projected over $500 million in peak sales for omadacycline.

Paratek hopes to build its case by showing omadacycline can reduce hospitalization costs. The two Phase 3 trials it has run so far enable patients to complete their antibiotics course at home, with pills, rather than entirely at the hospital. Paratek hasn’t released any analyses of omadacycline’s effect on hospital stays yet, but the first details are expected at a medical meeting later this month.

The company is also testing an oral-only regimen of omadacycline—meaning no hospital stay—for patients with moderate to severe skin infections, with data expected in June. If Paratek is successful, “there is a clear value-based argument,” Loh says.

The pneumonia data build upon recent momentum for Paratek. Last week, the company announced that its other antibiotic—seracycline, for acne—succeeded in two Phase 3 trials. Paratek doesn’t have U.S. rights to seracycline, however; partner Allergan (NYSE: AGN does. Paratek has full rights to omadacycline.