In September 2025, Taiwan’s Intellectual Property and Commercial Court (“IPCC”) rendered an appellate judgment[1], dismissing Boehringer Ingelheim’s appeal against the Taiwanese company Lotus Pharmaceutical. The case concerned a dispute over whether a party could be restrained from selling a generic drug approved for a non-patented indication which was accused of having been used off-label for patented indications. The court’s opinion provides important guidance on how Taiwanese courts assess the likelihood standard in the patent infringement clause and clarifies the establishment of a causal relationship between a generic product’s presence and doctors’ off-label prescriptions.

  Boehringer Ingelheim International GmbH (“Boehringer”) owns three Taiwanese patents--Nos. I268922, I285635, and I418351--relating to nintedanib, a kinase inhibitor used to slow down the progression of pulmonary fibrosis and some lung cancers. Particularly, during the Patent Extension Term (“PTE”) starting in 2010 for the earliest one, the ‘922 patent is specifically restricted to the use of the drug for idiopathic pulmonary fibrosis (IPF; Indication 1), while the ‘635 patent is specifically restricted to its use for systemic-sclerosis-associated interstitial lung disease (SSc-ILD; Indication 2).

  The defendant, Lotus Pharmaceuticals Inc. (“Lotus”), developed a generic version of nintedanib called Nifibro for which regulatory approval was obtained from the Taiwan Food and Drug Administration (TFDA). Although the active ingredient, dosage form and strength were identical to those of Boehringer’s brand drug Ofev, the approved labeling limited the generic product’s use to a different indication, namely, progressive fibrosing interstitial lung disease (PF-ILD; Indication 3).

  Boehringer filed a lawsuit seeking a preventive injunction to stop any further commercialization of Lotus’s product, claiming that doctors might clinically prescribe Lotus’s generic version of nintedanib off-label for patients of the patent-covered Indications 1 and 2 because the three indications do not clearly distinguish and some symptoms may overlap. Boehringer argued that there existed a real and imminent risk that the generic product would be used for purposes falling within the patented scope. The court of first instance dismissed the claim, finding that the alleged risk was speculative.[2] Boehringer appealed and the IPCC again sided with Lotus.

  Boehringer emphasized that the composition and dosage of Lotus’s product were the same as those of Ofev. Since Indications 1, 2 & 3 appear to be indistinguishable, doctors would be likely to treat these related interstitial lung diseases similarly. Arguably, it was highly foreseeable that doctors would prescribe Lotus’s generic product for the same patient group as Ofev. Boehringer also cited national health insurance statistics showing that most prescriptions of nintedanib in Taiwan (88%) related to Indications 1 and 2 rather than Indication 3. Hence, allowing the free launch of the generic product was tantamount to the creation of conditions conducive to infringement, even if Lotus never explicitly promoted off-label use.

  In defense, Lotus countered that, according to the marketing authorization and labeling, its generic product was limited to Indication 3 only, and was medically reasonable and clinical practice compliant. Since the PTE restricts protection to only Indications 1 and 2, Lotus’s product fell entirely outside the scope of Boehringer’s extended rights. As Lotus further emphasized, even when doctors prescribe Nifibro for indications 1 and 2, such an event is an independent medical decision for which Lotus as the product manufacturer cannot be held responsible. The drug regulations also prohibit labeling or advertising for unapproved uses. Lotus had fully complied with said medical regulations. It further argued that when a patient is diagnosed with Indications 1 and 2, their use of the patented drug will be covered by their health insurance; there is no incentive to pay for the generic product out of pocket. In short, Boehringer’s theory was not evidentially supported.

  Whether there was actual infringement requiring the construction of a claim and an analysis of the accused product was not an issue. Instead, the question presented at the IPCC was whether the generic product posed an imminent risk of infringement of Boehringer’s patents during the extension period. After reviewing, the IPCC reaffirmed that the answer was no.

  In its reasoning to determine how such a risk of infringement could arise, the IPCC began by adopting the jurisprudence approach of causation. Infringement liability takes place when there is “sufficient causation” connecting the infringing activity and the occurrence of the injury. In more detail, as assessed sequentially, the causal condition is found first, and then the issue of whether the act and the inquiry are “sufficiently related” is determined. In line with the rule of thumb, when considering all the facts present at the time of the act, it is assessed objectively whether the same result could have occurred with the same conditions under general circumstances. If affirmative, the condition is considered a sufficient condition for the result. The act and the result are connected in a sufficient causation. In the event of infringement liability, a causal relationship between the accused infringing activity and the occurrence of the injury is sufficient.

  In the present case, the label of Lotus’s accused generic drug specifically indicated that it is intended for Indication 3 by providing clinical doctors and medication dispensary personnel with a specific drug administration guidance. Relevant policy mechanisms have clear regulations regarding how it can be used either according to the label or off label, coverage and reimbursement rules under national insurance, procurement, and inventory management. Furthermore, certain conditions must be met in order for a physician to prescribe the accused generic drug off label for patients with Indications 1 or 2. There are a number of factors which would have to be taken into account.

  More specifically, it is doubtful whether national insurance would cover such off-label use, since in principle only the prescription according to a drug label’s indication can be covered. The health authority would only reimburse a prescription for other indications under exceptional circumstances and such exceptions would be publicly announce; Lotus’s Nifibro product has thus far not received such exceptional approval from the health authority. Furthermore, if an off-label use is not covered by national insurance, it remains doubtful whether a patient would be willing to pay out of pocket for the additional sum required for a generic product when a patented drug is offered with insurance coverage. Therefore, it is not necessarily the case as Boehringer complained that the accused generic drug would be prescribed for Indication 1 or Indication 2 in the clinical practice.

  When the assessment of liability causation is taken into account, even in the extreme scenario of the accused product being prescribed for Indications 1 or 2, Lotus’s offering of the product constitutes at most a “causal condition” or “factual causation”. It falls far short of meeting the sufficiency requirement. Consequently, without a sufficient causal link, Boehringer’s argument of there being a high likelihood of the accused product being prescribed for Indications 1 or 2 (thus leading to a direct infringement of its patent rights) is not reasonable or admissible.

  The IPCC dismissed Boehringer’s appeal and additional claims, fully upholding the first-instance decision. Boehringer was ordered to bear all litigation costs.

  The IPCC’s decision underscores the practical limit of enforcing pharmaceutical-related patents under the drug-patent early dispute resolution system to seek preventive injunctions in Taiwan. Pharmaceutical patentees cannot win lawsuits by relying solely on the biochemical identity of the drug substances or theoretical possibilities of off-label prescriptions. In order to succeed, they must present solid evidence demonstrating a sufficient link between the availability of the generic product and an event of off-label prescription.