Vifor (International) Limited Vs Dr Reddys Laboratories Limited and others (July, 2023) involves multiple cases filed by Vifor (International) Limited against various defendants including Dr. Reddys Lab., wherein the Delhi High Court reviewed alleged infringement (and validity) of Vifor’s patent titled “Water Soluble Iron Carbohydrate Complex and a Process for Producing Water Soluble Iron Carbohydrate Complex'” (referred to as “IN’536”). The patent covers a novel water-soluble iron carbohydrate complex called FERRIC CARBOXYMALTOSE (FCM), used for intravenous treatment of iron deficiency and anaemia. Various specific issues dealt with by the Court are elaborated hereafter:
Product-By-Process Claims
The Court emphasized that product-by-process claims are indeed recognized in India. These claims define a product based on the process used to obtain it rather than its chemical or structural characteristics. However, the scope of protection is limited to the specific process described in the patent. In this case, Vifor’s patent (IN’536) contained product-by-process claims that covered the water-soluble iron carbohydrate complex FCM obtained by using a specific process involving an aqueous hypochlorite solution as the oxidizing agent.
Infringement Analysis
The Court’s primary purpose was to determine whether the defendants’ process for producing FCM fell within the scope of Vifor’s patent claims. The defendants argued that their process was different from Vifor’s patented process because they used Oxone as the oxidizing agent instead of aqueous hypochlorite, and they began with starch hydrolysate with a DE value greater than 20 instead of maltodextrin with a DE value less than 20.
Different Processes and Non-Infringement
The Court found that the defendants’ process indeed used different oxidizing agents (Oxone) as well as different starting materials (starch hydrolysate with a DE value greater than 20). The Court highlighted that the patent claims were intentionally restricted to the specific process using aqueous hypochlorite, thereby making it inappropriate to claim infringement against a process using Oxone. Consequently, the Court held that the defendants’ process was prima facie non-infringing because it fell outside the scope of Vifor’s product-by-process claims.
Conscious Limitation of Patent Scope
The Court further underscored that the patent applicant (Vifor) consciously and knowingly limited the scope of their claims to the specific process using aqueous hypochlorite. This emphasized that the patent’s protection was confined to what was explicitly claimed, and a narrower scope was chosen deliberately for patent protection.
Prior Interim Injunctions
Vifor sought to rely on previous interim injunctions granted in similar cases in support of their request for an interim injunction. However, the Court rejected this argument, stating that the earlier injunctions did not specifically address the scope of the patent. The injunctions were primarily based on territorial jurisdiction issues rather than the merits of the infringement claim.
INNs and Monopoly Claims
The Court clarified that no monopoly can be claimed on International Nonproprietary Names (INNs). These names are used to identify pharmaceutical substances internationally, and they cannot be subject to patent protection. This clarification addresses any confusion or claims related to monopolies on product names.
Relief Granted
Based on its analysis, the Court allowed the defendants to continue manufacturing and selling their product, FCM. However, the Court restrained the defendants from using the specific process claimed under Vifor’s patent (IN’536) since if done so, it would fall under the scope of their product-by-process claims. This implied that the defendants can produce and sell FCM but by using their own process (or any process other than the one claimed by Vifor in “IN’536”), which was de facto different from the patented process (prima facie).
Importance of the Observations
The Court though made it clear that its observations and opinions in this judgment were preliminary and subject to further examination and consideration in the full trial. This judgment was not a final conclusion and will not affect the final adjudication of the suits. The Court also indicated that the matter was scheduled for further consideration before the Roster Bench on a later date, subject to the orders of the Hon’ble Judge In-charge.
Overall, the judgment clarifies the concept of product-by-process claims under the Indian patent law, reaffirms the importance of properly limiting the scope of patent claims, and emphasizes the need for a comprehensive infringement analysis based on the specific process described in the patent. The Court’s decision helps establish a legal precedent in patent law concerning the validity and enforcement of product-by-process claims in India.
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