​In our “Exclusivity Under Attack” article published in August 2019, we discussed the U.S. District Court for the District of Columbia’s opinion in Braeburn Inc. v. FDA, holding that FDA’s use of “innovation” in determining exclusivity under §505(b)(2) of the Federal Food, Drug, and Cosmetic Act (FFDCA) was too broad.  The court remanded the matter to the Agency to more clearly frame the definition.  This issue arose because multiple §505(b)(2) new drug applications (NDAs) were filed for variations of buprenorphine delivery, and some applications were blocked by market exclusivity granted by FDA to previously-approved competing products.
In late November 2019, FDA quietly responded to the plaintiff, Braeburn, Inc., in a decision that was not highly publicized but that nonetheless has significant ramifications for exclusivity decisions not only for §505(b)(2) NDAs, but also for orphan drugs and other novel products such as combination products and gene therapies.  In its response to Braeburn, FDA defined “exclusivity” in terms of clinical benefit to a patient population that is studied in a clinical trial.  Based upon FDA’s response to Braeburn, the central question becomes:  What unique clinical question about the safety and effectiveness of the active moiety is answered, for the first time, by the clinical trials that were conducted for—and are essential to—the application’s approval?
FDA’s conclusion is that exclusivity is available when there is no other data available to support the application; in other words, exclusivity does not apply to aspects of the drug product for which the clinical investigations that were conducted were not essential.  According to FDA, as the number of applications for therapeutic improvements in the active moiety increases, the exclusivity that is available to sponsors of these incremental advances becomes more limited and usually narrower in scope.
In its decision, the Agency emphasized the fact-specific nature of exclusivity determinations.  Clinical trials must address clinically meaningful differences that are unique (i.e., previously unanswered questions of clinical relevance).  Thus, clinical safety benefits must be unique to the product that is the subject of the §505(b)(2) NDA.  Accordingly, there is a relationship between the scope of exclusivity awarded and the changes to the product that required new clinical investigations which were essential for approval. 
However, FDA also noted that the context-specific nature of exclusivity decisions may create divergent results across different therapeutic areas.  A product change may be considered an innovation in one therapeutic area, but not in another therapeutic area if clinical trials would be unnecessary to approve the change.  Moreover, sponsors must recognize that changes to warnings or other risk information on a drug label must be included in generic drug labeling as well; therefore, such changes do not qualify for exclusivity.
Because FDA’s exclusivity decisions are fact-specific, it is difficult to rely upon a previous FDA exclusivity decision in a new situation—particularly as the industry continues to develop new technologies, combination products, and digital products.  FDA’s evaluation of what is known about a previously-approved drug product, combined with new clinical evidence generated by clinical investigations of another drug product containing the same active moiety, presents what we call “the clinical benefit dilemma”:

• What data and outcome is considered clinically relevant?
• What new question is being answered for the first time, particularly when competition already exists?
• Who determines what qualifies as clinical benefit?  This is a particularly hot topic in the oncology and orphan drug areas, as evidenced by ongoing public dialogue about the scope of clinical benefit and expanded access, as well as Oncologic Drugs Advisory Committee (ODAC) discussions.
• As technology advancements are made and we gain more knowledge about cellular mechanisms of action, will clinical benefit look different in the future—and who will decide?

It is important to recognize that FDA is neither a hydra nor a monolith.  The Center for Drug Evaluation and Research (CDER) is composed of many divisions and offices, including the Oncology Center of Excellence; the Office of Combination Products; the Office of Orphan Products Development; the Office of Pediatric Therapeutics; and the Office of Women’s Health.  Each one of these divisions and offices takes a different approach in determining what constitutes clinical benefit.  Opinions vary, and some reviewing divisions are more open-minded than others.  It is important to recognize these differences, along with the fact that every division and office believes that it is the ultimate decision maker.  Although often true, sponsors must be aware that FDA may consult the CDER Exclusivity Board, while the Office of Chief Counsel will have the final say in the most competitive, contentious, and economically-significant situations.
Because of the economic ramifications involved in many of these decisions, the courts often become entangled in these legal decisions.  However, the courts do not realistically appreciate the scientific nuances or practical aspects involved in drug development.  Courts look for FDA to make reasonable decisions, and they are becoming more cautious about providing FDA with unfettered discretion.  To this end, at least two current U.S. Supreme Court Justices have discussed revisiting the Chevron standard of review, which for decades has given great deference to Agency decisions.
Where do these recent developments leave industry?  While congressional groundwork has started on “21st Century Cures 2.0” and the 2022 user fee re-authorization bill, we are entering a new era of patient activism.  In this new era, the concepts of clinical benefit and clinical relevance are quickly becoming the 21st century equivalent to the 20th century standard of adequate and well-controlled clinical investigations.  Drug development no longer is only about showing efficacy and safety of a product.  It now requires that sponsors demonstrate product value.  Sponsors would be wise to take all of these facts into account when developing their drug products and when seeking exclusivity for their §505(b)(2) NDA.

By: Edward Allera
Chairman of The 505(b)(2) Platform 
The New Drug Landscape
FDA approves approximately 120 new drug applications (“NDAs”) annually.  Of these, applications submitted under § 505(b)(2) of the Federal Food, Drug, and Cosmetic Act (“FFDCA”) constitute the majority of NDAs filed (70%) and approved (60%) each year.  Although the sample size is not extensive, these data are important to both FDA and the individual companies that file or contemplate filing a § 505(b)(2) NDA.  These figures illustrate the fact that sponsors are increasingly developing drug products that are not new chemical entities (“NCEs”) but, rather, rely upon certain data and information that is already known about drugs that FDA previously approved.  These data also highlight the fact that FDA is increasingly  asking for “new” data that will be required to approve a § 505(b)(2) NDA.
In the case of § 505(b)(1) NDAs, the primary reason that these applications fail—both today and historically—is due to the sponsor’s failure to establish the correct dosage.  This is a well-known phenomenon that can cut an otherwise promising § 505(b)(1) development program short as the sponsor works to restart and recruit more patients to its clinical trial program.  The associated costs concurrently increase as does the lost opportunity cost.  Likewise, our research suggests that § 505(b)(2) NDAs face an analogous problem that accounts for many of the failures of these particular applications that arise even before an NDA is filed—namely, the Safety Paradox.
The Safety Paradox
In the case of § 505(b)(1) NDAs, FDA approves a particular drug containing a particular active moiety for a particular indication.  The NDA safety package for an NCE is centered on these and other characteristics.  All too often, however, a § 505(b)(2) sponsor concludes that FDA’s historical safety assessment of the NCE (i.e., the reference drug) will satisfy the safety requirements for the § 505(b)(2) NDA.
Sponsors are often enamored with the potential new use of the drug, often after studying the drug for a number of years.  The entity becomes like their child; they see only the positive side.
What § 505(b)(2) sponsors frequently fail to realize is that drug safety is not static.  The reference drug’s post-approval adverse event profile and pharmacovigilance data may reveal safety signals that require addressing in the § 505(b)(2) NDA.  Furthermore, the product or indication changes that a § 505(b)(2) sponsor introduces in its own drug development package means that the § 505(b)(2) NDA will need to include new safety data reflective of these changes despite the fact that the drug has already been shown to be safe by adequate tests by all methods reasonably applicable to show if the drug is safe.- hence the Safety Paradox.  
The Safety Paradox slows the road to § 505(b)(2) NDA approval, leading to unexpected delays.  Often these delays can be anticipated, and therefore minimized or eliminated, with careful planning during the § 505(b)(2) NDA drug development process.
Why the Safety Paradox?
The approval of a § 505(b)(1) NDA for an NCE does not provide a § 505(b)(2) sponsor with carte blanche to rely upon the reference drug’s safety package without it developing new safety data that reflects the change(s) introduced into the product or its use.  For example, a change in patient population, dosage form, dosage strength, route of administration, length of use, or indication which is the essence of a § 505(b)(2), creates different questions and may require §505(b)(2) sponsors to develop new safety data related to the change.
Moreover, § 505(b)(2) sponsors must be cognizant of what safety events may have arisen since FDA approved the reference drug:  Has the drug become a huge commercial success leading to vastly greater patient exposure than anticipated leading for greater patient exposure? Have new safety signals emerged in a given patient user subpopulation?  Has the concomitant use of certain medications led to a spike in adverse event reporting?  What labeling changes has the § 505(b)(1) sponsor introduced since approval that may offer insight into post-approval safety challenges?  As more data on drug usage becomes available after controlled clinical trials are completed and the product is marketed to a broader patient population, the safety profile of any drug will more than likely change.  Further, issues may arise with other drugs in the same therapeutic class.  FDA expects that a § 505(b)(2) sponsor will consider these changes during its own drug development program.
These considerations are particularly relevant if a sponsor anticipates filing a §505(b)(2) NDA for an active moiety that has been approved abroad but not in the U.S.  In this case, the sponsor may rely on studies conducted by others as well as published literature.  However, FDA is often reluctant to accept this type of real world data for drugs marketed outside of the U.S., even when there is a long history of use.  This also creates a potential hurdle to approval that may well result in the need to conduct additional safety studies.  Often applications for U.S. were filed, and a safety issue arose that precluded or discouraged additional clinical work for U.S approval.  Thus is one facing a biased FDA reviewing division? Knowing whether and how much additional safety data will be required can only be addressed by engaging with FDA during the drug development process.
A § 505(b)(1) sponsor faces an approval path that is relatively straightforward, albeit lengthy and expensive.  The amount of preclinical data and the timing of such studies as they relate to the start of clinical trials can vary, but the basic required elements of the safety package and the questions to ask FDA are well-understood.  FDA has issued numerous safety guidance documents for potential sponsors that take into account safety studies for the method of administration, drug-drug interactions, drug-food interactions, fetal exposure, or potential carcinogenicity.
In the case of § 505(b)(2) NDAs, the drug approval path is shorter when the sponsor critically evaluates the type of safety data that is needed well in advance of NDA submission.  Advance preparation, including a thorough safety analysis of the reference drug, is as critical to §505(b)(2) NDA success as is a freedom to operate opinion relative to an active moiety’s patent protection.
           
Conclusions
Filing a § 505(b)(2) NDA is becoming an increasingly attractive option for introducing a drug to the market because of the ability to obtain regulatory exclusivity and to list patents in FDA’s Orange Book.  The Safety Paradox, however, remains an important issue for many § 505(b)(2) sponsors to consider.  To tackle the Safety Paradox, a sponsor must be willing to ask both itself and FDA difficult questions early in development.  Doing so will eliminate or reduce unexpected questions about the drug’s safety profile late in development, and will allow sponsors to proceed in the most timely and cost-efficient manner possible.
As a member of The 505(b)(2) Platform™ we can help you identify the need for a Safety Review and who can help you develop a multi-part analysis for your § 505(b)(2) NDA asset. A proper Safety Review helps minimize the risk of missing existing critical safety information about the reference drug, and develops the necessary additional safety data to support the proposed change to the reference drug. To become a member by registering at www.505b2.org/membership.