K-Drugs Eyeing $2 Billion US P-CAB Market... The Battleground Is 'Drug Pricing'

K-CAB Expected to Win FDA Approval in January Next Year
Zacubo Aims for U.S. Launch in 2029
U.S. P-CAB Prices Dozens of Times Higher Than PPIs
“A Strategy to Attract Mild Patients Is Needed”

Pharmaceutical companies that have rapidly reshaped the domestic gastroesophageal reflux disease (GERD) treatment market with potassium-competitive acid blockers (P-CAB) are now turning their eyes to the United States, the world's largest pharmaceutical market. The potential revenue from the P-CAB market in the United States is estimated at $2 billion (approximately 3 trillion won). However, as inexpensive generic proton pump inhibitors (PPIs) still dominate prescriptions and payers maintain high reimbursement barriers, industry observers point out that a different approach will be needed compared to the domestic market.

According to the industry on September 30, Braintree, the U.S. partner of HK inno.N, submitted a New Drug Application (NDA) for "K-CAB" (active ingredient: tegoprazan) to the U.S. Food and Drug Administration (FDA) in January. The application covers three indications: non-erosive reflux disease (NERD), erosive esophagitis (EE), and maintenance therapy after EE treatment. The approval is expected in January next year. If things proceed as planned, HK inno.N will be the first among Korean P-CAB developers to enter the U.S. market.

Onconic Therapeutics has also begun preparations for the U.S. launch of "Zacubo" (active ingredient: zastaprazan). The company is currently in discussions with the FDA regarding the design of a phase 3 clinical trial and plans to file an investigational new drug (IND) application within this year, aiming for a local launch in 2029. Daewoong Pharmaceutical's "Fexuclu" (active ingredient: fexuprazan) and "Padoprazan," which is being co-developed by Daewon Pharmaceutical and Ildong Pharmaceutical, are currently searching for local partners to oversee their entry into the U.S. market.

In the U.S. P-CAB market, "Voquezna" is essentially pioneering the field as the only product currently approved and marketed by the FDA. According to its distributor, Phathom Pharmaceuticals (Phathom), sales of Voquezna surged by 217%, from $55.3 million in 2024 to $175.1 million last year. This year, sales for the first half alone reached $132.58 million, significantly exceeding the previous year's performance. This suggests ample opportunity for latecomer Korean companies as well.

The challenge lies in the base of prescriptions. Unlike in Korea, in the United States, inexpensive generic PPIs are firmly established as first-line therapy, making it difficult to expand prescriptions for mild or non-erosive cases. The monthly price of Voquezna is about $650, dozens of times higher than that of generic PPIs, which cost between $5 and $30. For this reason, many insurance providers require "step therapy" and prior authorization, demanding patients try a PPI before covering a P-CAB. The American Gastroenterological Association (AGA) also recommends against using P-CABs as first-line treatment for non-erosive reflux or mild erosive esophagitis patients due to cost and accessibility.

Ultimately, experts believe that the success or failure of Korean companies in the U.S. depends as much on their pricing and insurance strategies as on clinical efficacy. Phathom plans to initiate a phase 3 trial of Voquezna in "as-needed" usage mode within the year. By leveraging the rapid onset of P-CABs, the strategy aims to reduce dosing frequency and lessen the cost burden for mild patients. In its U.S. phase 3 study, K-CAB became the first P-CAB to demonstrate superiority over PPIs, securing evidence to persuade insurers.

An industry insider stated, "The reason Phathom is investing significant resources in 'as-needed' clinical trials for Voquezna is that capturing the mild patient segment is essential to achieving blockbuster status. For Korean companies as well, the key will be providing both insurers and mild patients with a compelling reason to choose P-CABs over the inexpensive PPIs that have been used for decades."

This content was produced with the assistance of AI translation services.