HK inno.N has secured another legal victory in the second-instance ruling on the compound patent for its gastroesophageal reflux disease (GERD) treatment, K-CAB (ingredient: tegoprazan). The Intellectual Property Trial and Appeal Board (IPTAB) and the Patent Court have both ruled in favor of HK inno.N, ensuring the patent remains protected until 2031.

K-CAB, a potassium-competitive acid blocker (P-CAB) for GERD, was first approved in July 2018 and launched in 2019. Since then, it has expanded its indications and formulations, generating approximately $139 million in outpatient prescriptions last year, maintaining its position as South Korea’s market leader in peptic ulcer treatment. The drug is protected by a compound patent valid until 2031 and a crystalline form patent valid until 2036.

Originally set to expire in December 2026, the compound patent’s duration was extended to August 25, 2031, reflecting the time required for drug development and regulatory approval. However, generic drug manufacturers challenged this extension, filing a negative scope confirmation trial to launch their versions immediately after the original expiration date in 2026. They argued that the extended patent should apply only to K-CAB’s initially approved indications—erosive and non-erosive GERD—while new indications should remain outside its protection.

The IPTAB dismissed the claim last May, and the Patent Court has now upheld that decision, specifically addressing K-CAB’s indication for Helicobacter pylori eradication therapy. The court ruled that, as this treatment falls under acid-related disorders managed through acid suppression, it remains covered under the extended patent.

HK inno.N emphasized that this ruling affirms that Article 95 of the Patent Act should not be narrowly interpreted to limit patent extension only to originally approved indications. "This decision strengthens South Korea’s pharmaceutical and biotech innovation. We remain committed to maximizing the value of domestic new drugs through continuous research. Given that other ongoing lawsuits involve similar legal issues, we anticipate favorable outcomes," the company stated.

Meanwhile, litigation regarding K-CAB’s crystalline form patent, valid until March 12, 2036, is in the second-instance trial after HK inno.N lost the first ruling.