Vote May Lead to Confidence, Competition in MCM Market
By Mari Serebrov
After voting 17-1 that data from a National Institutes of Health (NIH)-sponsored animal study were sufficient to approve Amgen Inc.'s Neupogen as a treatment for radiation sickness, two FDA advisory committees told the agency that the data should be applied to all drugs in the same class.
With the Biomedical Advanced Research and Development Authority (BARDA) looking to procure a hefty supply of a granulocyte colony-stimulating factor (G-CSF) such as Neupogen for emergency use in case of a nuclear attack or accident, that was good news for Sanofi SA and Teva Pharmaceutical Industries Ltd., as well as Amgen. The recommendation would extend to Amgen's Neulasta (pegfilgrastim), Sanofi's Leukine (sargramostim) and Teva's Tbo-Filgrastim (filgrastim). (See BioWorld Today, May 2, 2013.)
Friday's discussion at the joint meeting of the Oncologic Drugs and the Medical Imaging Drugs advisory committees also could open the medical countermeasure (MCM) door for future biosimilars. Teva's Tbo-Filgrastim, approved by the FDA last year as a new biologic, is one of seven Neupogen (filgrastim) biosimilars approved in Europe, where it is marketed as TevaGrastim. None of the others are approved in the U.S., where Neupogen enjoys patent protection until later this year.
Since the U.S. biosimilar path was still under construction when Teva began developing its filgrastim for the U.S. market, the Jerusalem-based company opted to go the new biologic route. As part of a settlement with Amgen, of Thousand Oaks, Calif., Teva agreed to not launch the drug until at least November.
That agreement wouldn't necessarily stop Teva from competing for BARDA's request for proposal (RFP) for 2.8 million courses of a G-CSF for the national stockpile.
While it would be too late for other biosimilars to get in on the current RFP, there are likely to be more opportunities in the future. Filgrastim has a refrigerated shelf life of about three years, which means the stockpile would need to be replenished regularly. In light of concerns about slow market adoption of biosimilars, a potential government contract could be an enticing incentive for drugmakers working to get Neupogen or Neulasta biosimilars approved in the U.S.
However, if future BARDA RFPs are structured like the current one, biosimilars with limited market share could find themselves at a disadvantage. In addition to the 2.8 million courses, the RFP calls for the selected vendor to provide a continuous "inventory bubble" that the government could access as needed, said John McManus, president and CEO of Aeolus Pharmaceuticals Inc.
Providing consistent overproduction could be difficult for a biosimilar maker with limited inventory and capacity, he told BioWorld Today, and it would be riskier for the government to rely on a company that doesn't have much demand for inventory.
Sponsors of filgrastim biosimilars weren't the only ones with cause to be happy about Friday's adcom meeting. Companies such as Aeolus that are working on other MCMs for acute radiation sickness were encouraged by the acceptance of the animal data for Neupogen, as well as the cooperation and support expressed by BARDA, the FDA and NIH. It was "very, very positive from our point of view," McManus said.
If the FDA goes along with the advisory committees and approves filgrastim to treat radiation-induced myelosuppression, it would be the first radiation MCM approved under the Animal Rule, which was enacted to allow pivotal trials in animals when human testing would be considered unethical.
"There used to be, not that long ago, [the feeling] that it would be impossible to get a drug approved through the Animal Rule that the FDA wouldn't do that," McManus said. That perception made it difficult to attract investors.
Now, "the tide is turning, and investors are becoming more comfortable with the space," he added, noting that a growing number of other types of MCMs have been approved under the Animal Rule.
The recent BARDA RFP and last week's meeting should strengthen that confidence because they showed what needs to be done to address current issues and provided guidance on the size and structure of government procurements.
"Having an example of how this works is very helpful," McManus said. Aeolus, of Mission Viejo, Calif., is approaching the procurement stage with AEOL10150, an MCM intended to combat the pulmonary effects of acute radiation syndrome. The broad-spectrum catalytic antioxidant compound is being developed as an MCM under government contracts, including a 2011 contract from BARDA worth up to $118 million. (See BioWorld Today, March 30, 2011.)
Five efficacy studies of the drug should be completed within the next 12 months, McManus said.
Although AEOL10150 has patent protection into 2022, McManus knows it may eventually have to compete with generics, as well as new or improved drugs, for government contracts. But for now, he said, "we're not concerned about looking over our shoulders. We just need to get to the finish line."
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