Billion-Dollar Antacid Market Heats Up Amid New P-CAB Entrants and PPI Resilience

Amid the pharmaceutical winter, certain sectors remain hot, and the market for acid-related diseases is undoubtedly one of them. The development of the oral acid suppressant market has progressed from the foundational stage of H2 receptor antagonists (H2RAs), through the maturation phase driven by proton pump inhibitors (PPIs), to the current launch of potassium-competitive acid blockers (P-CABs). Today, this multi-billion-dollar arena is poised for a new round of competition.

The oral acid suppressant market is mature yet continues to exhibit growth. Pharmaceutical companies have consistently intensified their R&D efforts, accelerating the iterative advancement of acid suppressants, thereby providing clinicians and patients with a broader range of therapeutic options.

PPIs, as the cornerstone of treatment for acid-related disorders, have long dominated and continue to dominate the landscape of acid suppression therapy. In recent years, due to the impact of national centralized procurement and key monitoring lists, core PPI products may face a "reshuffling" crisis.A review of the first seven rounds of China’s National Centralized Drug Procurement (VBP) reveals that among oral proton pump inhibitors (PPIs), omeprazole was included in the third round, while esomeprazole and pantoprazole were included in the fourth round. Lansoprazole and rabeprazole have not yet been incorporated into the national VBP; however, given the large number of manufacturing approvals for these agents, they are inevitably facing imminent inclusion in centralized procurement. Furthermore, omeprazole, lansoprazole, esomeprazole, pantoprazole, and rabeprazole were all prominently listed in the “Second Batch of National Key Monitoring Directory for Rational Drug Use” (hereinafter referred to as the “Second Key Monitoring Directory”), released by the National Health Commission on January 13, 2023. With the normalization of national centralized procurement and the implementation of the “Second Key Monitoring Directory,” will PPIs, as the cornerstone drugs for acid-suppressive therapy, step down from their pedestal and fade into obscurity, much like H2 receptor antagonists (H2RAs) did in the past?

The answer is no.

First, from a market perspective, exclusive PPI products still have promising market prospects.For instance, Livzon’s ilaprazole was not included in the Second Batch of Key Monitoring Catalogue. Owing to its status as an exclusive product and patent barriers, it faces no risk from national centralized procurement. Since 2019, oral ilaprazole has sustained rapid growth; rather than being adversely affected by policy changes, it has swiftly escaped competitive pressures while PPI generics were constrained by volume-based procurement, thereby achieving a dominant increase in both market share and sales volume.

Secondly, from the perspective of treating acid-related diseases. Today, more than three decades after proton pump inhibitors (PPIs) entered clinical practice, the treatment of acid-related diseases has evolved into an era characterized by targeted therapy for specific patient subgroups and rational drug use.Second-generation proton pump inhibitors (PPIs), represented by rabeprazole and ilaprazole, achieve ulcer healing rates comparable to those of first-generation PPIs. They are characterized by non-enzymatic metabolism and predominant metabolism via CYP3A4, respectively, resulting in minimal influence from CYP2C19. Consequently, they can be co-administered with drugs such as clopidogrel.

3. As the new trendsetter, will P-CAB reshape the landscape of acid-suppression therapy?

Acid suppressants have evolved from H2 receptor antagonists (H2RAs) to proton pump inhibitors (PPIs), and further to potassium-competitive acid blockers (P-CABs), following a trend of increasingly potent acid suppression. H2RAs indirectly inhibit the proton pump and exhibit relatively weak acid-suppressing effects; consequently, they have been gradually replaced by PPIs in clinical practice. PPIs are converted into sulfenamide derivatives in vivo, which form irreversible bonds with the proton pump, thereby inhibiting hydrogen ion secretion into the gastric lumen. Their acid-suppressing efficacy is well-balanced: they comprehensively inhibit active proton pumps without affecting newly synthesized ones. Clinically, this achieves therapeutic goals while avoiding excessive disruption of the normal physiological functions of gastric acid. For patients requiring more potent acid suppression, double-standard-dose PPI therapy can be employed. For patients with recurrent symptoms, switching between different PPIs is an option. Thus, PPIs can effectively manage nearly all patients with acid-related disorders.In contrast, P-CABs reversibly and competitively block the potassium-binding site of the proton pump, inhibiting the hydrogen-potassium exchange and reducing hydrogen ion entry into the stomach. By bypassing the need for metabolic activation in vivo, P-CABs have a faster onset of action. Moreover, unlike PPIs, P-CABs can inhibit both resting and active proton pumps, resulting in more potent acid suppression. While such potent acid suppression offers positive therapeutic benefits for certain critically ill patients, it does not provide additional clinical benefit for the majority of ordinary patients. More potent acid suppression is not necessarily better; the principle that "excess is as bad as deficiency" applies equally to acid-suppressive therapy.Under normal conditions, the pH of gastric acid ranges from 0.9 to 1.8 (rising to approximately 3.5 after meal-induced dilution). Overall, Chinese and Asian populations have fewer parietal cells than Westerners, resulting in lower gastric acidity. Currently, PPIs, administered at standard or double doses, can cover ordinary patients as well as those with Grade C and D reflux esophagitis (RE), fully meeting clinical needs. Furthermore, the safety profile of P-CABs requires further validation, and their role as a foundational treatment for digestive diseases warrants continued observation. The fact that the FDA has not yet formally approved any P-CAB for market entry indicates that P-CABs still have a long way to go before gaining widespread clinical acceptance. Therefore, the launch of P-CABs in China does not signify their replacement of PPIs as the cornerstone of acid-suppressive therapy, but rather serves as a supplement to PPI-based treatment.

In summary, amid the policy impacts of national centralized procurement and the "Second Batch of Key Monitoring" list, as well as competition from the market launch of P-CABs, PPIs will not lose their cornerstone status in acid-suppressive therapy. Exclusive PPI products and next-generation PPIs soon to be launched will enjoy better development opportunities. The acid-suppressant market is not a zero-sum game requiring a life-or-death struggle. Innovation is the soul of a nation’s progress and an inexhaustible driver of a country’s prosperity and development. In the field of chemical drugs, Class 1 new drugs, as defined by China’s "Provisions for Drug Registration," represent the national level of innovative drug development and constitute the most challenging form of innovation in chemical pharmaceuticals. In the process of independent R&D of acid suppressants and the replacement of foreign generic drugs with domestically produced alternatives possessing independent intellectual property rights, we still see NDA submissions for innovative PPIs, such as Xuanzhu Biopharma’s anaprazole sodium.

The inflection point has arrived, and the competition is fierce. Between exclusive PPIs and P-CABs, who will shape the future landscape of the acid-suppression market? Only time will tell.