'Next-Generation Stomach Medicine' K-New Drug Golden Era... Onconic's New Drug 'Jacubo' Approved

Development Name 'Jastaprajan'
3rd Domestic P-CAB New Drug Approved

In the treatment market for gastroesophageal reflux disease, a domestically developed new potassium-competitive acid blocker (P-CAB) drug that has improved both ease of administration and efficacy compared to existing drugs is dominating the global market. Among the P-CAB formulations commercialized worldwide, three are already domestic new drugs.

Onconic Therapeutics Research Institute Exterior View [Photo by Onconic Therapeutics]

The Ministry of Food and Drug Safety approved Jacubojeong, a treatment for erosive gastroesophageal reflux disease, as the 37th domestic new drug on the 24th. Developed under the generic name Zastaprazan by Onconic Therapeutics, a subsidiary of Jeil Pharmaceutical, the drug was submitted for approval to the Korean Ministry of Food and Drug Safety in June last year. The company plans to launch it within the year after completing reimbursement registration procedures.

As a result, out of the five P-CAB formulations commercialized worldwide, three are domestic new drugs. HK Innoen’s K-CAB was the first domestic P-CAB drug launched in 2019, followed by Daewoong Pharmaceutical’s Pexuclu in 2022. The others are Takeda Pharmaceutical’s Takecab from Japan and Carephar Pharmaceutical’s Beiwen from China, which have been approved in major countries worldwide.

P-CAB drugs, including Jacubojeong, are rapidly expanding their market share by emphasizing higher convenience and efficacy compared to proton pump inhibitors (PPIs), which have traditionally dominated the gastric drug market. Although PPIs are acid secretion inhibitors, their main active ingredients only show efficacy in the presence of stomach acid. Therefore, they must be taken before meals and have a delayed onset of action. In contrast, P-CABs inhibit acid secretion regardless of stomach acid presence and can be taken at any time. They also have the advantages of rapid and prolonged efficacy, which has led to their fast-growing market share.

According to pharmaceutical market research firm Ubist, among the top 10 prescribed drugs for gastroesophageal reflux disease in the first quarter of this year, all PPI products saw a decline in sales, whereas K-CAB and Pexuclu continued to show sales growth. The overall market share of P-CABs has also surged to around 20%.

Last October, Professor Oh Jeong-hwan of the Department of Gastroenterology at Eunpyeong St. Mary's Hospital publicly presented the Phase 3 clinical data of Zastaflazan for the first time at the United European Gastroenterology Week (UEGW) held in Copenhagen, Denmark.
[Photo by Onconic Therapeutics]

This approval was based on the results of a phase 3 clinical trial conducted on 300 patients with gastroesophageal reflux disease across 28 domestic institutions, using esomeprazole, an existing PPI drug, as the control group. The company explained that the trial confirmed excellent mucosal defect healing effects and safety. According to the key phase 3 data presented at the European Gastroenterology Week (UEGW) in October last year, Jacubojeong showed a treatment rate of 97.9% after 8 weeks of administration, demonstrating non-inferiority compared to the control group’s 94.9%. Notably, at the 4-week mark, the treatment rate was 95.1%, 7.4% higher than the control group, proving its rapid efficacy.

Professor Jeong Hoon-yong of the Department of Gastroenterology at Seoul Asan Medical Center, who led the phase 3 trial, said, “Jacubojeong shows rapid efficacy within one hour of administration and maintains a gastric hydrogen ion concentration (pH) above 4 for 85% of the 24-hour period, the highest among P-CAB drugs. Its excellent duration of efficacy is expected to greatly help improve nighttime acid secretion symptoms.”

John Kim, CEO of Onconic Therapeutics, said, “It is very meaningful and an honor that a specialized new drug R&D company like Onconic Therapeutics has achieved new drug approval from clinical trials to final approval, which was once the exclusive domain of large pharmaceutical companies. Based on Jacubojeong’s excellence, we will do our best to further solidify our position as a new drug R&D company that can enhance the value of K-new drugs both domestically and internationally.”

Onconic Therapeutics also plans to accelerate research and development to expand Jacubojeong’s indications to include gastric ulcers. In particular, following the technology evaluation passed in January based on the imminent approval of Jacubojeong, the company plans to file for preliminary review for listing on the KOSDAQ within the year, aiming to secure related funds.