GSK Outpaces Pfizer in the First Round of the RSV Vaccine Battle

On November 1, GSK released its third-quarter financial report. The report showed that the third-quarter revenue was 8.147 billion pounds, a year-on-year increase of 10%. Among them, the recombinant respiratory syncytial virus (RSV) vaccine Arexvy performed the most outstandingly, with the first quarter sales since its launch reaching 709 million pounds, approximately 860 million US dollars.

Pfizer's Q3 financial report released on October 31 showed that the sales of its RSV vaccine Abrysvo in the first quarter reached 375 million US dollars.

GSK and Pfizer's RSV Vaccine Battle Has Already Begun. Currently, GSK Seems to Have the Upper Hand in This Competition. So Far, GSK’s Arexvy Has Been Administered to 1.4 Million People, While Pfizer’s Abrysvo Has Only Reached 800,000 People.

In May this year, GSK's Arexvy was approved for marketing by the U.S. FDA for the prevention of lower respiratory tract disease (LRTD) caused by RSV in people aged 60 and above. This is the world’s first approved RSV vaccine and also the first RSV vaccine to demonstrate significant statistical and clinical efficacy in people aged 60 and above. Following its approval in the U.S., Arexvy has now been approved for marketing in Europe, Canada, Japan, and other countries.

This approval is based on the outstanding Phase III clinical data (AReSVi 006) of Arexvy.

This clinical trial result shows that among 24,966 subjects aged 60 years and above, the overall efficacy of Arexvy was 82.6%, and its efficacy against severe RSV-LRTD (with at least two lower respiratory tract symptoms or signs) was 94.1%. Among the elderly with at least one underlying medical condition (such as certain cardiopulmonary and endocrine-metabolic diseases), the efficacy of Arexvy reached 94.6%. Additionally, Arexvy demonstrated consistent preventive efficacy against both RSV subtypes, A and B (84.6% vs 80.9%).

In terms of safety, Arexvy demonstrated good tolerability and safety. The adverse events (AE) reported in the study were generally mild to moderate and transient, with the most common AEs being injection site pain (60.9%), fatigue (33.6%), myalgia (28.9%), and headache (27.2%).

To further expand the population eligible for vaccination, GSK is currently evaluating the efficacy of Arexvy in adults aged 50-59 in a Phase III clinical trial (NCT05590403).

Its preliminary results show that Arexvy’s immune response in adults aged 50-59 is no less than its performance in adults aged 60 and above, including the subgroup with underlying conditions. The safety and reactogenicity data of Arexvy in this trial are also consistent with the results from the initial Phase III program.

GSK Chief Strategy Officer Tony Wood stated that the company will present the analysis and data results of the trial at the US Advisory Committee on Immunization Practices (ACIP) meeting. It is expected to submit an sBLA application to the FDA in the fourth quarter to seek approval for the use of Arexvy in the 50-59 age group.

Arexvy Opens Up a Huge RSV Market for GSK. According to data released by GSK, Arexvy accounts for nearly two-thirds of the U.S. RSV vaccine retail market, with 1.4 million American adults having already received this vaccine. Currently, about 83 million adults over the age of 60 in the U.S. are at risk of RSV. GSK's financial report indicates that Arexvy’s total sales for 2023 could exceed $1 billion.

Data from VCBeat Research shows that the global RSV drug market was approximately US$1.8 billion in 2020 and is expected to grow to US$12.8 billion by 2030, with a compound annual growth rate (CAGR) of 21.4%. Drugs suitable for infants and young children account for the majority of the market, expected to represent over 90% of the global RSV drug market.

RSV Drug Market Becomes a "Hot Cake," Attracting Numerous Innovative Pharmaceutical Companies, Intensifying RSV Market Competition.

In May this year, Pfizer's Abrysvo also received FDA approval for use in adults aged 60 and above, officially kicking off the competition with GSK. However, in the first round of confrontation, GSK defeated Pfizer.

Three months after Abrysvo was approved, GSK sued Pfizer for infringement related to Abrysvo. In the lawsuit, GSK accused Pfizer's RSV vaccine of infringing on four of GSK’s patents, which are related to the antigens used in GSK's RSV vaccine, Arexvy. Subsequently, in the first sales round, the revenue from GSK's Arexvy was more than twice that of Pfizer's Abrysvo during the same period.

But Pfizer doesn't seem to have completely lost, as its Abrysvo has also made breakthroughs in populations other than the elderly. On August 21, Pfizer announced that the FDA approved the expansion of Abrysvo's use to pregnant women in weeks 32-36 of gestation to protect newborns from RSV infection. This is the first RSV vaccine for use in pregnant women.

However, Pfizer also has to compete with Beyfortus, an RSV antibody jointly developed by Sanofi and AstraZeneca. Beyfortus was approved for marketing in July this year, and in August, the ACIP included Beyfortus in the childhood and adolescent immunization schedule for the prevention of lower respiratory tract diseases caused by RSV in infants. It provides protection for newborns entering or born during the first RSV season and infants under 8 months of age.

In addition to the two "powerhouse contenders" GSK and Pfizer, innovative pharmaceutical companies such as Moderna, Bavarian Nordic, and Advaccine are also catching up in the RSV field.

In January 2023, Moderna released positive results from the pivotal Phase III clinical trial of its RSV vaccine mRNA-1345. The data showed that mRNA-1345 had a maximum efficacy of 83.7% in preventing RSV-LRTD. Existing safety data analysis indicated good tolerability with no safety concerns identified.

Currently, the indication of mRNA-1345 for preventing RSV-LRTD in middle-aged and elderly populations is in Phase III clinical trials, while its use for pediatric populations is in Phase I clinical trials. In July this year, Moderna submitted a marketing authorization application for mRNA-1345 to the European Medicines Agency, Swissmedic, and the Therapeutic Goods Administration (TGA) of Australia.

In April 2023, Bavarian Nordic announced that the global Phase III clinical trial of its investigational vaccine MVA-BN®RSV for the prevention of RSV in individuals aged 60 or older had completed the required number of cases for the primary efficacy analysis. The primary efficacy analysis of the Phase III clinical trial is expected to be completed by mid-2023.

In October 2023, Advaccine published a paper on the Phase II clinical data of its RSV vaccine ADV110 in "medRxiv." The data showed that after vaccination with ADV110, the geometric mean concentration (GMC) of antigen-specific antibodies increased in all groups compared to the baseline levels before immunization. Moreover, the response rate in each group exceeded 80%. The ADV110 vaccine demonstrated good safety, tolerability, and immunogenicity.