[Edaily Reporter KIM SUNG-JIN ] The success or failure of new drug development no longer ends with obtaining approval. “IP management” has emerged as a key topic across the industry, as the ability to protect intellectual property (IP)—including patents and exclusive sales rights—for as long as possible has become a core competitive factor that determines profitability and the capacity for follow-up research and development (R&D) investment. Amid this trend, SK BIOPHARMACEUTICALS (326030) is drawing attention as a company pursuing an aggressive IP strategy, having staked its future on extending the exclusive marketing period for its flagship product, the epilepsy drug “cenobamate” (brand name: Xcopri).
“Pushing for Extension of Excopri’s Exclusive Sales Period”SK BIOPHARMACEUTICALS(326030)is recognized as the only South Korean company to have independently developed a new drug—from candidate compound discovery through U.S. Food and Drug Administration (FDA) marketing approval—and managed its global sales. As Excopri, the company’s cash cow, continues to set new sales records since its U.S. launch, the company’s medium- to long-term strategy is expected to hinge on whether the IP period is extended. SK BIOPHARMACEUTICALS plans to create a virtuous cycle by investing the cash generated from Exkofri into R&D costs for the development of next-generation new drugs.
According to industry sources on the 6th, SK BIOPHARMACEUTICALS is currently pursuing an extension of Excofry’s exclusive marketing period. The exclusive marketing period refers to the timeframe during which a single company is guaranteed the exclusive right to sell a specific drug. It serves as a form of patent protection that delays the launch of generic versions by competitors and ensures sales revenue.
Currently, Excofry’s exclusive marketing period in the U.S. runs through 2032, and SK BIOPHARMACEUTICALS is making every effort to extend this period as long as possible. During its second-quarter earnings conference call on the 5th, SK BIOPHARMACEUTICALS stated, “We are working to extend the exclusive marketing period for Excofry.”
Excofry was one of SK BIOPHARMACEUTICALS’ earliest development projects; after receiving Investigational New Drug (IND) approval from the U.S. FDA in 2005 and completing clinical trials, the company launched the product in the U.S. market in 2020. In March 2021, it obtained marketing authorization from the European Commission (EC) and launched the product in the European market under the name Ontosri in June of the same year.
Since its launch in the U.S. market, Excofry has set new sales records every quarter and established itself as SK BIOPHARMACEUTICALS’ flagship product. Excofry’s sales, which stood at just 7.7 billion won in the fourth quarter of 2020, surged to a staggering 224.4 billion won in the second quarter of this year. Considering that SK BIOPHARMACEUTICALS’ total revenue for the second quarter of this year was 247.4 billion won, Excofry is effectively driving the company’s overall performance.
The gap with competing new drugs is also widening. According to SK BIOPHARMACEUTICALS, the total number of Excofry prescriptions (TRx) in the U.S. for the second quarter was approximately 143,000, an 8.4% increase from the previous quarter. In contrast, Briviact—a strong competitor and the top-selling drug in the U.S. epilepsy treatment market—is estimated to have seen a sharp decline in prescriptions this year as generics entered the market following the expiration of its patent.
Although SK BIOPHARMACEUTICALS’s second-quarter earnings report did not mention specific competitor product names, it showed that TRx for competitor products labeled A, B, and C plummeted starting last year and continuing into this year. This is precisely why SK BIOPHARMACEUTICALS is staking its future on extending the exclusive sales period for Excofry. Analysts believe the company has concluded that securing this exclusive sales period alone will ensure a stable revenue base for the next few years. In the first half of this year, the company also established a new intellectual property (IP) team dedicated to lifecycle management.
“Evergreening”: The Core of Patent StrategySK BIOPHARMACEUTICALS’s push to extend Excofry’s exclusive sales period is part of a strategy known as “Evergreening,” which involves adding new patents to existing drugs nearing patent expiration to maintain exclusivity for as long as possible.
Evergreening has long been established as a core strategy used by major international pharmaceutical companies to maintain the competitiveness of their products. A prime example is global pharmaceutical giant Merck, which filed a large number of patents for its biggest hit, the immuno-oncology drug “Keytruda” (generic name: pembrolizumab). Merck generated a staggering $31.7 billion (46 trillion won) in revenue last year from Keytruda alone, leaving the company with no choice but to devote its full efforts to protecting Keytruda’s patents. In fact, a review of the key patents for Keytruda listed on Merck’s official website reveals as many as 12 patents—a number far exceeding that of Merck’s other pharmaceutical products.
However, simply creating a web of patents does not necessarily prevent competitors from entering the market. The substance patent for Keytruda in South Korea is set to expire in 2028, and #Samsung Bioepis, a leading domestic biosimilar company, is already pursuing product development aimed at circumventing existing patents in anticipation of Keytruda’s substance patent expiration.
Since 2024, Samsung Bioepis has been conducting comparative studies on pharmacokinetics, efficacy, safety, and immunogenicity between its product—currently under development through global Phase 1 and 3 clinical trials in patients with non-small cell lung cancer—and the originator drug, and released topline results last June. A Samsung Bioepis official stated, “We are currently in the final stages of the clinical trials.”
In South Korea, Yuhan Corporation is also well-known for having cast a dense patent net around “Lecraza” (active ingredient: lazertinib), a non-small cell lung cancer treatment. In November 2009, the company filed a first-to-file patent for kinase inhibitors, and after the technology was transferred to Yuhan in 2015, it also completed regular patent applications in the U.S. and Patent Cooperation Treaty (PCT) applications. Since then, it has been reported that Johnson & Johnson (J&J), the U.S. pharmaceutical giant that acquired the technology in 2018, has been attempting to extend the patents related to Lecraza. Lecraza is the first domestically developed anticancer drug by a Korean pharmaceutical company to receive approval from the U.S. FDA, and it is a third-generation targeted lung cancer treatment.
Full Patent Protection Unlikely… Strategy to Secure a Competitive EdgeThere are two main methods for extending patents. One is a substance patent, which protects the chemical or biological structure of the compound or molecule itself; in the U.S., the Patent Term Extension (PTE) allows for an extension of up to five years. This system compensates for the period during which patent rights cannot be exercised while a new drug undergoes clinical trials and regulatory review.
SK BIOPHARMACEUTICALS has already successfully utilized this system to extend the expiration date of its substance patent by five years, from 2027 to 2032. Going forward, the company will effectively need to rely on other patents—such as those covering formulations, manufacturing methods, uses, administration methods, and combination therapies—to maintain patent protection; however, it is understood that achieving such protection will not be easy.
Kim Soon-woong, managing partner at Jeongjin Patent Law Firm, stated, “It is difficult to predict the likelihood of success in protecting a product’s patent term by utilizing patents related to changes in dosage form or other factors.”
For this reason, the industry views this strategy not as a means to fully protect the patent, but rather as a tactic to secure the upper hand in negotiations following the launch of generics or biosimilars. An industry official noted, “From the perspective of a company developing generic drugs, no matter how many circumventing strategies they employ, it is difficult to fully grasp all the patents held by the original drug manufacturer,” adding, “It is quite common for them to launch the generic product first and then engage in patent litigation with the original drug manufacturer.” The source continued, “During this process, pharmaceutical companies reach a compromise by entering into royalty agreements; the more existing patents a company holds, the greater its leverage in negotiations.”
