BioPharma, Pharma

Report: Pfizer battles originators over biosimilars; but new study shows first one approved is equivalent

The study can assure clinicians that Sandoz’s Zarxio works just as well in febrile neutropenia as originator Amgen’s Neupogen, author says in interview.

New York-based pharmaceutical company Pfizer is alleging that other large drugmakers are trying to block access to its biosimilar products and has taken the battle online, into the courts and to regulators, according to a news report.

Bloomberg reported Tuesday that Pfizer has been battling companies like Johnson & Johnson, Amgen and Roche. Pfizer sought to enter the biosimilars market in 2015 when it spent $17 billion to buy generic drugmaker Hospira, a firm that had been a leader in making biosimilars, mainly for the European market. In particular, Pfizer accused Amgen and Roche of using social media to mislead doctors and patients about biosimilars’ effectiveness and comparability to their branded counterparts.

But at least one biosimilar version of an Amgen drug was shown in a study published earlier this month to be equivalent to the reference product.

The study, published Sept. 3 in the journal ClinicoEconomics and Outcomes Research, compared Amgen’s reference product, Neupogen (filgrastim), with biosimilar Zarxio (filgrastim-sndz), made by Sandoz, the generics arm of Swiss drugmaker Novartis, with the goal of showing what happens in “real-life” settings outside of clinical trials. Specifically, it examined the efficacy of the two products among cancer patients treated for febrile neutropenia resulting from chemotherapy. Febrile neutropenia is a common complication of anticancer therapy and occurs when patients with neutropenia – meaning abnormally low counts of white blood cells called neutrophils – experience an accompanying fever.

Examining Medicare Advantage patient data from March 2015 and June 2016 among 3,297 patients receiving Neupogen and 162 receiving Zarxio, it found that adjusted incidence of febrile neutropenia was equivalent between the two groups. The difference in size between the two study groups was because Zarxio was so new during the study period, lead author Dr. Lee Schwartzberg, executive director of the West Cancer Center in Memphis, Tennessee, explained in a phone interview. As such, the statistical analysis used the propensity matching method to ensure the two groups were similarly weighted and to correct for any biases. In early 2015, Zarxio became the first biosimilar to receive Food and Drug Administration approval under the abbreviated biosimilars approval pathway created under the Affordable Care Act in 2009.

“What clinicians want to know is, when they reach for a biosimilar product, is it going to work just the same as what they’ve been using for years now,” Schwartzberg said. “I think the answer from this study is, one can be assured that you can get the same result using the biosimilar.”

Still, he cautioned against attempting to extrapolate the study’s results to other biosimilars as they must go through their own validation processes. However, he said the study could be a model for looking at other biosimilars. “I know clinicians will want to see similar data for [biosimilars] because they’re not used to using anything except the originator product, but I’m very confident we’ll be able to show such data,” he said.

Since Zarxio’s approval, biosimilars of numerous other products have been approved as well, including cancer drugs like Roche’s Avastin (bevacizumab) and Herceptin (trastuzumab) – both used to treat solid tumors – and Johnson & Johnson’s chemotherapy-associated anemia treatment Procrit (epoetin alfa). Biosimilars for autoimmune diseases have been approved as well.

Photo: Dmitrii_Guzhanin, Getty Images