FDA rejects Novartis’ biosim app for Amgen blockbuster

Buried deep down in Novartis’ ($NVS) Q2 results out this morning was a previously unknown rejection by the FDA for its copycat version of Amgen’s ($AMGN) blockbuster drug Neulasta (pegfilgrastim).

The biosimilar, coming out of its Sandoz unit, was seeking the same license as Amgen’s original med--a long-acting granulocyte colony stimulating factor, which is used to bolster white cells in patients undergoing chemotherapy for cancer.

The drug is one of Amgen's top-selling products, with around $5 billion in sales, and much of that revenue stream coming from the U.S.

But for the first time, Novartis has said in its second-quarter update that the FDA rejected its biosim application for the drug, which was accepted by the regulator last November. The review was designed to last 10 months.

In a brief update noted deep down in its results, Novartis said: “Sandoz received a complete response letter from the FDA for biosimilar pegfilgrastim candidate (Neulasta). We are working with the agency to address remaining questions.” No further details were given.

This will be a blow to the company and perhaps more widely to other biosim manufacturers, just when it looked like the regulatory side of things was becoming a little more predictable.

Many of the issues this year have revolved around each company trying to block the other with patent disputes; earlier this month, both Novartis and Amgen had seen FDA advisory committees give a unanimous yes to their new, separate biosimilars, with final decisions expected by fall of this year.  

But other companies have received complete response letters, notably Pfizer’s ($PFE) new Hospira unit, whose biosimilar version of Amgen’s kidney disease drug Epogen (epoetin alfa) was rejected last year. The FDA asked the companies for more data from their application with a resubmission planned for this summer. 

Last year, Novartis in fact became the first company to gain a biosimilar approval in the U.S. (there have been biosims in Europe for around a decade) for its copy of Amgen’s other chemo side effects drug Neupogen (filgrastim)--a slightly different formulation of Neulasta.

It is unclear what the Sandoz CRL refers to, and whether the issues have to do with a clinical trial or manufacturing concerns.

In a statement released last year along with the FDA acceptance, Sandoz said it had conducted three pivotal clinical trials on its biosimilar: one pharmacokinetic and pharmacodynamic study in healthy volunteers and two comparative efficacy and safety studies in breast cancer patients (PROTECT 1 and 2).

It said these “demonstrate that the proposed biosimilar is highly similar to the reference product.” The biosim drug was also accepted by the European Medicines Agency back in February. 

During its Q2 call, Novartis' CMO and head of drug development, Vasant Narasimhan, said: “We received the complete response letter from FDA at the end of June. And we have worked closely with the agency throughout this program and are continuing to work with the agency to determine how best answer their questions.” 

Pushed by an analyst about what was going on with the CRL, Narasimhan said that biosimilars are “obviously complex filings where we have different elements we need to work through. So, I don't think we're ready to discuss the details of the response because we still need to work through with the agency how best to resolve their concerns. But as I have stated, we'll keep you updated as we work through the issue.”

Novartis did not return a call to FierceBiotech about the CRL. 

- check out its Q2 results

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