Let’s talk about Non-Biologic Complex Drugs (NBCD). If you look at the FDA’s recent actions relative to raising the issue of quality and performance of generic products and working with outside partners to seriously investigate the problem, you’d think that NBCDs are an obvious top of mind agenda item for the agency to consider and act on via Guidance. But, as with many difficult regulatory questions, predictability comes at the expense of ambiguity – and regulators have a penchant for embracing ambiguity.
When it comes to NBCDs (as with so many other issues), predictability is power in pursuit of the public health.
As my friend and former FDA colleague Dr. Scott Gottlieb has pointed out, a year ago, the Food and Drug Administration quietly posted a public notice that it wanted to hire an independent lab to test a generic drug that it had already approved. FDA wanted to make sure the drug was safe and effective.
The issue concerned a copy formulation of a complex, intravenous medicine used to replenish kidney-dialysis patients’ stores of iron. FDA had approved this “generic” version of the drug in March 2011 because it believed that laboratory data showed that the replica version of the drug was the exact same as the original branded medicine it was copied from. In announcing the request for independent testing of the generic version, FDA was indirectly saying it might have been wrong.
FDA was going back to get more evidence – including data looking at how the drug was behaving in patients – to make sure that its original decision was sound. Additional evidence was needed because this type of drug represents a new chapter in FDA drug approvals. By law, generic drugs are supposed to contain identical copies of the active ingredient of the original branded medicine that they are copied from. With almost all generic drugs, making identical copies has been relatively easy because the original medicine was a small molecule, which has a simple molecular structure. In contrast, complex drugs involve large molecules and are difficult to copy. In fact, their physical and chemical properties may not be fully understood. Even so, FDA has begun to approve generic copies of complex drugs.
Now, on the anticipated eve of one of the most significant generic drug approval decisions in recent years—involving another complex drug—the lesson from the generic IV iron episode bears reminding. FDA is widely known to be considering the approval of a generic version of Teva Pharmaceutical’s blockbuster drug for multiple sclerosis, Copaxone. The patents covering Copaxone for its 20mg/ml strength expired on May 24th. After patent expiration, FDA could approve generic copies of the drug at any time. But some of the same challenges that caused the agency to struggle with and sometimes stumble over its similar previous decisions still linger, and will color FDA’s decision concerning Copaxone.
Gottlieb believes (and I concur), that when it comes to evaluating copies of these complex drugs, the fact is FDA doesn’t have very good tools and policies. These drugs slip between FDA’s other generic drug constructs. They are less complex than biological drugs, which have their own separate law governing how the agency should review and approve copy versions. (Unlike with the generic drug law, the approval of copy versions of biologicals generally must be supported by evidence from human studies.) But non-biological complex drugs are far trickier than generic versions of the normal, small molecule pill drugs that FDA is accustomed to evaluating. It’s that framework for these small molecule drugs that FDA has been trying to apply to these complex drugs.
These challenges illustrate a need to reconsider how FDA approves copy versions of complex drugs. Perhaps different approval standards should be used. Current law already contains an appropriate alternative to the generic drug law in the pathway used for the review and approval of copies of biological drugs, which gives FDA more latitude when it comes to the data it can use as a the basis for these approvals. Some of these principles could be applied to a new category that addresses the complex drugs. Or Congress could re-write certain aspects of the generic drug law, tailoring generic drug principles to the unique challenges of copying complex drugs.
As Gottlieb points out, FDA also needs to change its practices when it comes to these complex drugs, to more clearly establish reliable principles for how generic copies of these medicines can be safely brought to market once brand-name patents have expired. It needs to develop these scientific principles in a more transparent and inclusive process that leverages the expertise that FDA doesn’t readily posses to discern these laws of drug science.
The complex drugs fall in a regulatory gap. FDA has tried to retrofit the “Hatch Waxman” generic drug law and policies that govern approval of small molecule drugs to these complex drugs, with sometimes troubling results. Regardless of the decision FDA makes with Copaxone, it remains clear that Congress and FDA alike need to re-examine the regulatory process when it comes to these intricate drugs.
The problem is that FDA has refused to define these complex drugs as distinct from normal, small molecule medicines. That has forced the agency to rely on less information in approving these complex copies than it probably would like. The agency’s desire to try and squeeze these complex drugs through its existing generic law approval pathway may have as much to do with political expediency as with good science. FDA is probably well aware that getting Congress to define a distinct category for these medicines, and give FDA proper tools, could be a heavy political lift. So FDA is doing what it often does: trying to massage its existing authorities and regulatory practices to fit novel challenges.
The challenge isn’t just the generic drug law, which doesn’t allow FDA to look at much more than bioequivalence data. The setback is what FDA has done in response to these limitations, to try and retrofit its existing policies on complex drugs where the generic drug principles are sometimes poorly suited. And FDA has entered this new chapter in generic drug approvals largely under the radar. Congress and the public generally are not aware of the new direction FDA is taking.
Instead of acknowledging that it needs a broader scope of data to ensure “sameness” (the statutory standard for a generic drug approval) between the original and the copy drug, FDA has typically divined new science in these circumstances – coming up with novel principles of drug science to determine how two drugs can be declared the same by comparing laboratory data that FDA often establishes on its own novel principles. Such is the case with the gene expression data that FDA is examining in the case of Copaxone.
The foundational problem here is that the FDA is in the business of evaluating data against known standards, not establishing those standards de novo. The enterprise of establishing standards upon which two highly complex drugs can be judged the same requires a great deal of expertise in discrete areas of science. This sort of expertise doesn’t exist in one place, and certainly isn’t the province of FDA. That’s not a knock on FDA, or its scientists. This sort of work just isn’t the business that Congress has tasked the agency with doing. FDA is not staffed or resourced to take on the task of developing novel principles of biology and discovering the standards for measuring how drugs affect biological systems.
Per Gottlieb, As a result, FDA has often established principles that are at times embarrassingly incomplete, and sometimes spectacularly wrong. The re-adjudication of the generic IV iron approvals is one example. The problems FDA had in 2008 assuring safety and effectiveness of generic, copy versions of intravenous heparin is another example. FDA had to recently walk back guidance it put out on how to copy a popular eye drop that was another complex formulation. In each case FDA had established some principles upon which the agency thought it could reliably determine that two complex drugs were the same. In each case, FDA was wrong.
Not subtle – but 100% on target.
FDA needs to adopt a more transparent and inclusive process for developing the scientific principles upon which it makes judgments on NBCDs and draft guidance that generalizes these principles, preferably well in advance of patent expirations that create the opportunity for generic entry. By establishing them in an open process, FDA would make this important knowledge generally available, and would lower the barrier to market entry by generic firms of different levels of technical sophistication. It should be emphasized that FDA’s current lack of transparency makes it hard for many generic-drug companies to get on the playing field. Transparency, per Gottlieb, could promote generic competition.