AstraZeneca’s PPI Nexium still leader despite P-CAB challenge in GERD treatment

AstraZeneca Korea said its flagship proton pump inhibitor (PPI) Nexium has maintained its market leadership in gastroesophageal reflux disease (GERD) treatment, even as it faces growing competition from a new class of drugs known as P-CAB (potassium-competitive acid blockers).

At a press conference marking Nexium's 25th anniversary in the Korean market, medical experts and company officials highlighted the drug's established safety profile and clinical benefits while acknowledging the changing competitive landscape.

Launched in 2000, Nexium (ingredient: esomeprazole) has been a dominant player in the GERD treatment market. The drug holds the most approved indications among PPIs in Korea, with six different therapeutic applications including GERD treatment, H. pylori eradication, and prevention of NSAID-related gastrointestinal complications.

However, recent market data shows signs of pressure on Nexium's position.

According to pharmaceutical market research firm UBIST, while the overall PPI market reached 636.2 billion won ($443.4 million) in 2024, its growth has significantly slowed since 2021. Meanwhile, the newer P-CAB class drugs have shown remarkable growth, with their combined prescriptions rising from 30.4 billion won in 2019 to 286.4 billion won in 2024.

Nexium's own sales have declined from a peak of 45.6 billion won in 2020 to 29.1 billion won in 2024, despite maintaining its market position through a strategic partnership with Ildong Pharmaceutical since 2022.

During the press conference, experts highlighted that Nexium still offers benefits in the GERD treatment market.

"As an S-isomer-based PPI, Nexium has demonstrated a remarkable 98.9 percent treatment rate in GERD patients, building a solid foundation in the market,” Professor Jung Hwoon-yong of the Department of Gastroenterology at Asan Medical Center said. “The drug's MUPS (Multiple Unit Pellet System) formulation offers several advantages, including consistent pharmacological action, superior bioavailability, and reduced absorption variability.”

It can also be administered through gastric tubes when dissolved in non-carbonated water, enhancing patient convenience, Jung added.

Clinical studies have demonstrated esomeprazole's superior acid control capabilities compared to other PPIs.

In comparative trials against five other PPI medications including rabeprazole and lansoprazole, esomeprazole maintained intragastric pH above 4.0 for 14 hours, showing statistically significant improvement over other treatments.

The drug's effectiveness in long-term maintenance therapy was particularly notable in the Metropole clinical trial. The study showed that esomeprazole capsules achieved a remission rate of 83 percent, significantly higher than lansoprazole's 74 percent. This superior efficacy was consistent across all disease severity levels.

For patients taking NSAIDs, Nexium has also demonstrated significant preventive benefits. The VENUS clinical trial showed that after six months, only 5.3 percent of patients in the esomeprazole group developed ulcers, compared to 20.4 percent in the placebo group. Similar results were seen in the PLUTO study, where ulcer occurrence was 5.2 percent in the esomeprazole group versus 12.3 percent in the placebo group.

Competition between PPIs and P-CABs

The competition between PPIs and P-CABs is expected to continue, with P-CABs offering advantages such as longer-lasting acid suppression and fewer drug interactions. However, experts suggest that both drug classes will likely coexist, serving different patient needs and preferences.

Professor Kim Sang-gyun of the Department of Internal Medicine at Seoul National University Hospital provided detailed insights on the comparative efficacy of PPI and P-CAB.

"When new medications emerge, interest and usage naturally increase," Jung said. "However, existing drugs maintain their value. P-CABs provide an additional option for patients who might show suboptimal response to PPIs."

"The goal of GERD treatment is to control symptoms through acid suppression, but effects only last while taking the medication, leading to symptom recurrence and this necessitates long-term maintenance therapy, he added.

According to Kim, while P-CABs have been in use for about five years, PPIs like Nexium have decades of safety and efficacy data.

“When non-erosive reflux disease patients were studied, both treatments showed similar improvement rates,” he said.

Kim further elaborated on treatment decisions stressing that while PPI and P-CAB may show differences in their mechanisms of action, the actual symptom improvement experienced by patients may not differ significantly.

“If a patient's condition is well-controlled with PPIs, there's no immediate need to switch to P-CABs,” he said.

Professor Jung also highlighted Nexium's extensive clinical applications.

"Starting with GERD, Nexium has progressively expanded its indications to include NSAIDs-related ulcer treatment and prevention in 2005, Zollinger-Ellison syndrome treatment in 2007, and maintenance therapy following intravenous treatment for ulcer-related rebleeding prevention in 2010,” he said. “This has established Nexium as the PPI offering the broadest range of treatment options in Korea."

Jung further stressed that since GERD requires long-term medication, patient compliance is crucial.

“Many patients prefer to continue with their existing treatment that they're comfortable with,” he said. “The development of P-CABs hasn't made PPIs obsolete - it's simply provided us with another valuable treatment option in our clinical arsenal."