Onconic's Zastaprazan Injectable Enters Phase 3 in China for Peptic Ulcer Bleeding
Key Insights
Livzon Pharmaceutical (search) has dosed the first patient in a China Phase 3 trial of injectable zastaprazan in patients with peptic ulcer bleeding (search), Onconic Therapeutics (search) said on September 23.
The Phase 3 start triggered a $1 million development milestone payment to Onconic under the companies' 2023 Greater China licensing agreement worth $127.5 million.
The injectable targets an acute-care indication distinct from the erosive GERD indication of the oral formulation, which is under NMPA review after an August 2024 filing.
Onconic Therapeutics (search) said its potassium-competitive acid blocker (search) (P-CAB) zastaprazan has entered a Phase 3 trial of an injectable formulation in China, with licensing partner Livzon Pharmaceutical (search) dosing the first patient this month. The trial evaluates the efficacy and safety of injectable zastaprazan in patients with peptic ulcer bleeding (search), an acute-care indication distinct from the erosive gastroesophageal reflux disease (search) (GERD) indication pursued by the oral formulation.
The Phase 3 start triggered a $1 million development milestone payment to Onconic under the terms of the companies' agreement. Zastaprazan is marketed in South Korea as Jaqbo, also written Zaqubo.
Parallel tracks in China
Development of zastaprazan in China is advancing on several fronts at once. Livzon submitted a marketing authorization application for the oral formulation to China's National Medical Products Administration (NMPA) in August last year for the treatment of erosive GERD, and that review is ongoing. In May, Livzon began a Phase 3 trial of a Helicobacter pylori (search) eradication regimen.
The eradication regimen serves a different therapeutic purpose than GERD treatment. It combines zastaprazan, which suppresses gastric acid secretion, with antibiotics to eliminate H. pylori, a leading cause of gastritis and peptic ulcers. Livzon's annual report outlined a dual-dosage-form strategy linking the oral and injectable forms of zastaprazan, with plans to expand indications and dosage forms concurrently.
Milestone revenue accumulates
The two companies signed an exclusive technology transfer agreement in 2023 covering development, regulatory approval, manufacturing and commercialization of zastaprazan in China, Hong Kong, Macau and Taiwan. Total contract value is $127.5 million, including a $15 million upfront payment.
Milestones have followed each development step. Onconic received $5 million in August last year upon completion of the China Phase 3 trial and submission of the marketing authorization application, and $1 million in May upon entering the Phase 3 trial for H. pylori eradication therapy. The injectable Phase 3 entry adds a further $1 million.
Market context
China is one of the core markets for GERD treatments globally. Industry estimates citing market research firm IQVIA put the global GERD treatment market at about 40 trillion won, with China accounting for roughly 4 trillion to 6 trillion won of that, described as the largest single-country market. For injectables, China's market for injectable acid suppressants, used in acute care such as peptic ulcer bleeding (search), is estimated at at least about 11 billion yuan, or about 2.2 trillion won.
Livzon generates annual revenues exceeding 600 billion won in the gastrointestinal therapeutics segment and holds a sales and distribution network in China. Zastaprazan is a novel drug in the P-CAB class, which the companies describe as offering faster onset of action and longer duration of effect than existing proton pump inhibitors.
An Onconic Therapeutics (search) official said major clinical development results are continuing to come through, adding that the company will move into full-scale commercialization of zastaprazan in China once it wins local approval. A company representative said the expansion of indications and dosage forms is progressing rapidly on the strength of the Livzon collaboration, and that the local commercial value of zastaprazan is expected to materialize in earnest upon Chinese marketing authorization.
The approval outcome for the oral formulation, currently under review by Chinese regulators, will determine the timing of zastaprazan's commercialization in China. Once oral approval is completed, Onconic will be positioned to secure sales milestones and royalty revenues. If the injectable trial concludes successfully, the drug would cover the acute-phase indication of peptic ulcer bleeding (search), broadening its revenue base in China.