Patent battle over generic Inomax leaves five Mallinckrodt patents invalid as naturally occurring phenomenon

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On Tuesday, September 5th, the patent portfolio of UK-based pharmaceutical firm Mallinckrodt PLC (NYSE:MNK) suffered a large setback after a judgment entered in the District of Delaware found that five patents asserted by that company in an infringement suit are invalid under 35 U.S.C. § 101. The order entered by Judge Gregory Sleet also declared that Danbury, CT-based chemical company Praxair (NYSE:PX) did not infringe upon six other Mallinckrodt patents with a generic version of a respiratory treatment marketed in competition with Mallinckrodt’s Inomax. The legal challenge caused Mallinckrodt’s stock to plunge nearly 15 percent on the day that the ruling came out.

Among the patents invalidated by the District of Delaware include:

  • U.S. Patent No. 8282966, titled Method of Reducing the Risk of Occurrence of Pulmonary Edema in Children in Need of Treatment with Inhaled Nitric Oxide. It claims a method of reducing risks for pulmonary edema associated with a treatment by performing echocardiography to identify a child in need of an inhaled nitric oxide treatment, determining that the child has such a risk due to ventricular dysfunction, and then excluding the child from nitric oxide treatment if that treatment would cause pulmonary edema.
  • U.S. Patent No. 8795741, titled Methods for Treating Patients Who are Candidates for Inhaled Nitric Oxide Treatment. It claims a method for treating patients for hypoxic respiratory failure that reduces the risk of increasing pulmonary capillary wedge pressure leading to pulmonary edema in neonatal patients.
  • U.S. Patent No. 8846112, entitled Methods of Distributing a Pharmaceutical Product Comprising Nitric Oxide Gas for Inhalation. It discloses a method of providing pharmaceutically acceptable nitric oxide gas in a cylinder of compressed gas which is also designed to reduce adverse effects or serious adverse effects in patients undergoing nitric oxide treatments.

The recent order invalidating Mallinckrodt’s respiratory treatment patents arises out of a patent infringement suit filed in February 2015 by Ikaria Inc. and its subsidiary INO Therapeutics, which developed the patented technologies, against Praxair; this suit came less than a month before Mallinckrodt announced that it was purchasing Ikaria for a reported price of $2.3 billion. Mallinckrodt was listed among the plaintiffs in the case in a first amended complaint filed in January 2016. The infringement suit followed an abbreviated new drug application (ANDA) filed by Praxair with the U.S. Food & Drug Administration to market a generic version of the Inomax respiratory treatment. Praxair had made a Paragraph IV certification in the ANDA that its generic respiratory treatment would not infringe upon the patents held by Mallinckrodt.

Although redacted trial transcripts in the case won’t be available until October, a memorandum signed by Judge Sleet shows that Mallinckrodt’s patents were invalidated under the Section 101 patentability standard set by the U.S. Supreme Court in 2012’s Mayo Collaborative Services v. Prometheus Laboratories, Inc., a standard affirmed by SCOTUS’ 2014 decision in Alice Corporation v. CLS Bank International. Applying the two-step test for Section 101 patentability, the Delaware court found that the Mallinckrodt patents covered natural phenomenon which did not include an inventive step. The court found that patent claim limitations directed at echocardiography or severe adverse reactions did not satisfy the inventive concept step. “It does not matter what the severe adverse reaction is,” Judge Sleet’s memo reads. “Any reaction to treatment with iNO will be a natural phenomenon, dictated by the patient’s physiological response to the drug.”

The invalidation of the Mallinckrodt patents covering the Inomax treatment is a significant blow to the pharmaceutical company as Inomax sales reportedly contribute about 15 percent of Mallinckrodt’s overall revenues. Mallinckrodt’s most recently quarterly earnings report filed with the SEC in early August indicates that net sales of Inomax reached $125.5 million for the quarter ending June 30th, more than $4 million greater than net sales of Inomax during the same period in 2016. Through the first half of 2017, Inomax generated $253.9 million in net sales and the treatment is the second-best selling unit for Mallinckrodt after its injectable multiple sclerosis drug Acthar. Along with the recent patent infringement suit in Delaware district court, Mallinckrodt’s earnings report notes that the patents covering Inomax were also challenged by Praxair petitions for inter partes review (IPR) proceedings at the Patent Trial and Appeal Board (PTAB); the first petitions for IPRs on those patents were filed by Praxair in the same month that INO Pharmaceuticals and Ikaria first filed suit in Delaware.


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Join the Discussion

4 comments so far.

  • [Avatar for Anon]
    September 18, 2017 08:13 am

    Eric – exactly correct.

    Even today, as I note on another thread, I continue to run into “pharma types” and preferences being put forth that simply do not work for most all other art fields (e.g., “only composition claims with written in picture-claim format should be allowed”).

    This feeds another view that I have often put forth: when one looks carefully (and with critical thinking), the professed anti-software and anti-business method arguments simply boil down to be anti-patent arguments. There simply exists no congruent rational basis for the attempted distinctions that one may see as a mere after thought when those who would try to deny patent protection to software and business methods take the “gist” of their arguments and apply them to any other (including pharma) art field.

    I am not saying that CP in DC is one that has actively campaigned against software and business methods, so I cannot take examples of his personal stance as an example, but on another thread he DOES reveal his “preference” for that very type of picture claim composition.

  • [Avatar for Eric Berend]
    Eric Berend
    September 18, 2017 06:46 am

    @2., ‘CP in DC’:

    What truly makes “no sense”, is how Big Pharma provided much of the ‘heavy lifting’ (e.g., lobbying) that helped finally push the AIA into enactment.

    Then, they somehow belatedly realized even their own patents could been challenged with the new, destructive procedures they sponsored with their influence.

    It gets rather despicable with their next move, lobbying the U.S. Congress for special carveouts protecting only their particular IP.

  • [Avatar for CP in DC]
    CP in DC
    September 17, 2017 11:51 am

    Ok so patent eligibility is a plague upon pharma. If abstract ideas kill off high tech patents, “natural phenomena” kills off pharma. Compound patents survive, unless genomic DNA (Myriad). Methods of diagnosis or treatment are in peril. This issue has been on the frontline of pharma since Mayo.

    The Alice two step analysis never works. Step 2A: identify the exception, always gets pharma treatment and diagnosis claims. Courts and the PTO reason that a diagnosis or treatment merely recognize the natural phenomena and so must be excluded. Thereafter, the “rest of the claim” is examined to determine if “something more” is provided. The second step 2B always views any additional information at a high level of generality (contrary to Mayo) such that anything else is deemed post solution activity. There goes the claim down the drain.

    I’m not agreeing with this analysis but this is what is happening in courts, PTAB, and examination.

    So what is the claim? I don’t have time for all claims so I picked claim 1 of the ‘966 patent. I don’t know which claims were asserted.

    1. A method of reducing the risk of occurrence of pulmonary edema associated with a medical treatment comprising inhalation of 20 ppm nitric oxide gas, said method comprising:
    (a) performing echocardiography to identify a child in need of 20 ppm inhaled nitric oxide treatment for pulmonary hypertension, wherein the child is not dependent on right-to-left shunting of blood;
    (b) determining that the child identified in (a) has a pulmonary capillary wedge pressure greater than or equal to 20 mm Hg and thus has left ventricular dysfunction, so is at particular risk of pulmonary edema upon treatment with inhaled nitric oxide; and
    (c) excluding the child from inhaled nitric oxide treatment based on the determination that the child has left ventricular dysfunction and so is at particular risk of pulmonary edema upon treatment with inhaled nitric oxide.

    So (a) is identification of the patient population using known technology, i.e., echocardiography. I guess step (b) is the natural phenomena (law of nature) step (think natural correlation if test for A, you have B), so it’s excluded. Finally, step (c) the exclusion step, basically remove those having the natural phenomena, So if the court performed an Alice analysis like that, you get their result.

    Sorry but a proper analysis would take an enormous amount of time and detail that I don’t have right now.

    Pharma and biotech have been fighting this fight for years. Alice is unworkable. In re Chamberlain followed the PTO’s guidelines for allowable claims and the PTAB found them ineligible. No one (much less district court judges and examiners) know what they are doing. Sometimes we argue you need two inventions in one patent, the diagnostic step or method of treatment, and a second one dedicated to identifying apparatus, treating compound, or other.

    Makes no sense.

  • [Avatar for Anon]
    September 17, 2017 09:36 am

    IF allowed to stand, this notion of:

    Judge Sleet’s memo reads. “Any reaction to treatment with iNO will be a natural phenomenon, dictated by the patient’s physiological response to the drug.”

    will mean the end to ALL pharma patents.

    This may come about in two ways – the direct line of thought of Judge Sleet, or if Pharma attempts to step around that and go an indirect route, the indirect route – lacking the “natural human physiological” inventive step (as it were) – then steps outside of the claim having utility; as it is ONLY in that “natural human physiological” step that utility is obtained.

    WAY back when the Supreme Court starting laying down this attack on patent rights, in the aftermath of the Bilski decision (IIRC, or it may have been after Mayo), there were a number of German film clips featuring Hitler that were dubbed over to indicate a discussion of patent eligibility.

    A line in one of those clips has two women in an outer area reacting to Hitler’s rants by saying “at least business methods are not ‘laws of nature.’

    I thought at that time that it was only a matter of time before some judge somewhere extends the “natural” logic of the “laws of nature” exception to the pharma world with the realization that pharma quite often does not provide drugs that attack ills, but more often merely provides drugs that – when broken down by the human body, the resulting drugs, created in part BY the human body are the actual items providing the utility.

    A step removed from having that direct utility may be a step enough to eliminate a patent for a “mere chemical” when what is actually required to possess utility is supplied apart from the physical item that pharma wants the patent upon (or, as in the cases displayed here with method claims as opposed to composition claims, the critical method step is merely the human body doing what it would do anyway).

    I invite CP in DC especially (who on another thread indicates his background in pharma), to a discussion on this seemingly two-headed attack on pharma patents.