Will Amgen win another injunction against Regeneron’s Praluent?

Zachary Silbersher

Amgen ($AMGN) is about to square off once again against Regeneron ($REGN) and Sanofi over whether Praluent® should be pulled from the market.  Having prevailed at another jury trial earlier this year showing that Amgen’s PCSK9 protein patents are both valid and infringed, Amgen has renewed its bid for a court order enjoining Praluent® from the market.  The injunction hearing is scheduled for June 2019.  Over two years ago, Amgen prevailed after an earlier injunction hearing where the court ordered Praluent® to be barred from the market.  Will Amgen be able to prevail again? 

In March 2016, Amgen and Regeneron conducted an injunction hearing before the Honorable Sue L. Robinson of the District of Delaware.  Several months later, Judge Robinson issued a brief order agreeing with Amgen that an injunction should issue against Praluent®.  That order was quickly appealed to the Federal Circuit.  The Federal Circuit concluded that the jury improperly invalidated the patents.  As a result, the appellate court vacated the injunction and remanded the case back to the Delaware court to hold another trial on Regeneron’s liability.   

Because the Federal Circuit vacated the earlier injunction due to the jury’s determination on liability, the Court did not reach a full analysis of Judge Robinson’s prior entry of the injunction.  One may be inclined to take from that Amgen can easily sail through to another injunction.  In other words, having now corrected the prior deficiencies with the liability ruling, Amgen is more likely to prevail again on winning an injunction. 

Yet that is not necessarily so.  Rather, for a number of reasons, the landscape has changed in the past three years, and the old injunction decision will not necessarily read through to a new one. 

First, Judge Robinson has now retired, and the case is now being heard by a different judge, namely, the Honorable Richard G. Andrews.  The decision whether to grant an injunction is typically subject to a fair amount of discretion by the court.  Thus, whatever views we can glean from Judge Robinson’s prior injunction decision issued cannot necessarily handicap the upcoming decision because it will be decided by a different judge.

Next, an important difference between today’s injunction decision and the one from three years ago is that both Praluent® and Amgen’s drug Repatha® have now been on the market for three years.  During the last hearing, the drugs had only entered the market a matter of months before.  There is now considerably more data regarding how the drugs are faring in the market among doctors and how they are arguably impacting one another. 

During the 2016 injunction hearing, Amgen and Regeneron focused many of their arguments on dosing differences between Repatha® and Praluent®.  Regeneron argued at length that Praluent® comes in lower-dosages that allows doctors to titrate down to the therapeutic LDL levels, which could not be done with Repatha®’s single, high-dose formulation.  Amgen disputed this by arguing that there was no data showing that lowering LDL levels too far could be detrimental.

Now, however, the companies have three years of market-data at their disposal.  The principle disagreement is now whether or not the presence of Praluent® in the marketplace has irreparably harmed the market for Repatha®.  Amgen argues that it expected to be first-to-market with the first PCSK9-inhibitor drug, but was usurped by Praluent®.  As a result, rather than being the only PCSK9-inhibitor on the market, Repatha® has been forced to compete in a two-player market, which has resulted in price erosion and loss of market share.  This has been caused by insurers and formularies pitting the two companies against each other.  Combined with Regeneron’s alleged aggressive pricing tactics, Amgen argues that its market share for Repatha® has been irreparably harmed. 

Amgen also argues that, because of competition with Praluent®, Amgen has had to offer significant rebates to payers.  These rebates lower the net cost of the drug, but Amgen claims that the rebates have (counter-intuitively) also reduced demand for its drug.  That is because the rebates are to the payers, whereas the actual consumers of the drug do not realize or “see” any price reductions.   

At the heart of this debate is the fact that neither Repatha® nor Praluent® have performed as well in the market as expected.  Amgen blames the presence of Praluent® for that.  Yet, Regeneron argues that Repatha®’s disappointing sales have to do with factors unrelated to Praluent®.   

Namely, Regeneron argues that payers are concerned about the high costs of the PCSK9-inhibitors and have questioned their cost-effectiveness.  As a result, payers have erected utilization management, prior authorizations and other barriers to coverage of both drugs, Repatha® but also Praluent®.  Regeneron’s basic point is that, given the inherent concerns with PCSK9-inhibitors and the costs, payers would have negotiated price discounts and barriers to coverage for Repatha® whether or not Praluent® was on the market.   

This dispute will likely form the focus of the upcoming injunction hearing.  As the market is aware, there are clearly factors at play that have mitigated the success of PCSK9-inhibitors.  While those factors were hypothetical three years ago, today they are more evident.  Amgen faces the following challenge to winning an injunction, namely, pinning Repatha®’s disappointing sales almost solely on the presence of Praluent®.  That is not necessarily a hurdle faced three years ago 

Another factor that will be different in the upcoming injunction hearing relates to the public interest.  Even though the Federal Circuit’s remand of this case in 2017 did not turn Judge Robinson’s injunction analysis, the Court did comment on it.  That comment changes the burden for both parties in ways that did not exist three years ago. 

When deciding whether to grant a permanent injunction, courts consider four factors: whether the patentee will suffer irreparable harm, whether the patentee can be adequately compensated with money damages, the balance of hardships between the parties, and whether an injunction serves the public interest.  Judge Robinson found only two of those factors weighed in favor of an injunction (irreparable harm and inadequacy of money damages) and one of them (public interest) actually weighed against granting an injunction.  (The fourth factor, balance of hardships, was deemed neutral by Judge Robinson.) 

The Federal Circuit deemed this to be error.  It held that an injunction cannot issue if the court finds the public interest would be disserved.  Thus, on its second attempt, Amgen faces a higher burden to winning an injunction against Praluent®.  If it cannot convince the court that the public interest will not be disserved by enjoining Praluent®, (which Amgen failed to do last time,) then it will not be entitled to an injunction. 

Importantly, on the issue of public interest, Judge Robinson found that having a diversity of life-saving drugs on the market benefits the public interest.  As a result, she found that pulling a life-saving drug from the market, namely, Praluent®, would disserve the public interest.  Presumably, if that same finding carries over to the upcoming injunction hearing, that might mean Amgen necessarily cannot win an injunction. 

Yet, during appeal, the Federal Circuit handicapped Judge Robinson’s prior analysis.  It found that there cannot be a per se rule that pulling a life-saving drug necessarily harms the public interest, because otherwise, that would categorically bar a permanent injunction against any life-saving drug deemed to infringe a patent.  Thus, on this next round, Regeneron will have to work a little harder to demonstrate that pulling Praluent® from the market harms the public interest.

 On this point, Amgen argues that, because the two drugs are deemed substitutable by the FDA (since they are approved for the same indications), payers do not feel compelled to cover both drugs.  Thus, Amgen argues that the public will not be disserved by an injunction because Repatha® can do whatever Praluent® can do.   

Yet, that may no longer be true due to recent developments.  On April 27, 2019, after briefing on the injunction was closed, Regeneron notified the court that Praluent® had received FDA approval for a new indication, namely, to reduce the risk of unstable angina requiring hospitalization in adults with established cardiovascular disease.   

Importantly, Repatha® is purportedly not approved for that indication.  This may undercut many of Amgen’s arguments because Regeneron can now argue that if Praluent® is pulled from the market, certain patients will be deprived of possibly the only treatment for certain life-threatening conditions.  (Amgen has responded to this development, but that response remains under seal for now.)

Overall, the companies heavily dispute whether there are any significant clinical differences between Repatha® and Praluent®.  The fact is, they are not the same protein.  And so, it is not surprising that one drug may have benefits not shared with the other.  Judge Robinson was previously persuaded that enough differences between the drugs exist that the public interest would not be served by enjoining Praluent®.  Whether Judge Andrews feels the same way remains to be seen, yet this will likely be a significant factor in the court’s ultimate decision.

The injunction hearing itself is scheduled for June 2019.  (The hearing is actually spread out over several days between June 6 and June 21.)  At the hearing, Judge Andrews may make comments or questions indicating issues he perceives to be important to whether Praluent® should be enjoined from the market.