Fierce Healthcare's Fierce 15 of 2024

GSK, Pfizer Sales Of RSV Shots Slow As Vaccination Rates Ebb

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Sales of both GSK's and Pfizer's vaccines for respiratory syncytial virus dropped significantly in the last three months of 2024, compared the same period one year before.

In a earnings report Tuesday, Pfizer said sales of its vaccine Abrysvo fell 62% year over year in the fourth quarter. The company attributed the drop mainly to "a significant reduction in vaccination rates in the U.S." among older adults eligible for the shot after U.S. Guidelines were narrowed last summer.

GSK reported a similar state of affairs Wednesday. Sales of its RSV vaccine Arexvy declined 69% year over year due to lower demand "related to a more limited recommendation ... For individuals aged 60 to 74," as well "channel inventory consumption."

GSK has been the dominant player in the RSV vaccine market since Arexvy first gained approval in 2023, although Pfizer has made inroads into its market share. While initial launches for both companies' products were strong, sales have since been crimped by the changed U.S. Guidelines.

Last year, an advisory panel to the Centers for Disease Control and Prevention recommended that adults aged 60 to 74 years who are at high risk of severe RSV disease receive a shot, narrowing the prior guidance of "shared clinical decision-making" for all adults over 60 years. The committee still advised all adults 75 years or older get vaccinated for RSV.

The drugmakers have hinted at the guidance's impact in prior earnings disclosure, so the slowed fourth quarter sales are not entirely a surprise. In January, analysts from Jefferies highlighted in a client note how vaccination rates for RSV remained low, even as rates for COVID-19 and flu climbed.

Both GSK and Pfizer have been able to secure expanded approvals for their shots, but uptake in those groups may depend on revised recommendations. The Food and Drug Administration cleared GSK's shot for adults aged 50 to 59 years who are at increased risk of disease, while Pfizer received an OK for its vaccine in adults aged 18 to 59 years who are at similar risk.

Abrysvo is also approved for maternal immunization, which is meant to pass on temporary protection to newborns. Uptake in that indication offset some of the fourth quarter sales decline due to "strong demand" in the setting, according to Pfizer.

The CDC hasn't yet issued guidance on whether adults who already received either shot will need another dose later on to maintain protection from RSV. In October, Jefferies analyst Peter Welford told clients the probability of a two-year vaccination schedule for Arexvy was "low."

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Most recently, the FDA added warnings to Arexvy's and Abrysvo's labeling for an increased risk of a rare neurological disorder known as Guillain-Barré syndrome.

More broadly, GSK said Wednesday it will be "increasing and prioritizing R&D investment" in respiratory medicines, among other categories. It predicts low single digit declines in revenue from its vaccine unit this year, but overall expects its business to grow 3% to 5%.

Merck's Challenge To Pfizer's Prevnar Grows

Pfizer's longstanding dominance of the pneumococcal vaccines category could be threatened by Merck & Co, which has just reported new data on its V116 shot in older adults that could lead to regulatory filings.

V116 is a cocktail of 21 Streptococcus pneumoniae serotypes designed to have the most benefit in adult populations, and according to Merck has been shown to generate protective immune responses in both vaccine-naïve and vaccine-experienced adults aged 65 and over.

In one phase 3 trial involving patients not previously vaccinated with a pneumococcal jab – called STRIDE-3 – V116 showed "statistically significant immune responses" compared to Pfizer's Prevnar 20, the latest member of its Prevnar family, which leads the market with sales of $6.3 billion last year.

A second study, STRIDE-6, showed that V116 stimulated antibodies against all 21 S. Pneumoniae strains in adults who had previously received a pneumococcal vaccine at least one year prior to the study. Both studies also backed up the safety and tolerability of the shot, which Merck said was "comparable" to the comparator product.

The company plans to file for approval of the new vaccine on the strength of the data and, if approved, it will slot into its portfolio alongside Vaxneuvance (formerly V114), which covers 15 serotypes and was approved by the FDA in 2021.

Merck also sells an older shot called Pneumovax 23, which covers 23 serotypes, but is based on an older polysaccharide technology that does not stimulate the immune response as strongly as the newer conjugate vaccines.

In a statement, the drugmaker said it would be "the first pneumococcal conjugate vaccine specifically designed for adults," and covers serotypes responsible for 85% of invasive pneumococcal disease in individuals 65 and older.

Merck is taking a targeted approach with its vaccines, zeroing in on serotypes that cause problems in specific patient populations, and notes that V116 includes eight serotypes not currently covered by approved pneumococcal vaccines.

That's a little different from Pfizer, which has gone for broad-spectrum coverage of the most prevalent serotypes. For now, however, the Prevnar brand remains largely unscathed from Merck's challenge.

Vaxneuvance was launched after Pfizer introduced Prevnar 20, but debuted with FDA approval for paediatric use that wasn't forthcoming for Pfizer's 20-valent shot until earlier this year, setting it into contention against the older Prevnar 13 product.

Sales remain fairly modest at just over $100 million in the first quarter of this year, and some analysts believe V116 could be key to Merck's segmented strategy hover, along with V117, an earlier-stage project that will deploy its serotype selection approach to a paediatric vaccine.

"Despite the availability of current pneumococcal conjugate vaccines, many adults remain vulnerable to pneumococcal disease, especially those who are older," said Dr Eliav Barr, head of global clinical development and chief medical officer at Merck Research Laboratories.

"These results support the potential for V116 to become an important new preventative option for adults, regardless of prior pneumococcal vaccination status, by expanding coverage to include eight serotypes not currently included in any licensed vaccine," he added.

FDA Clears Pfizer's Prevnar 20 For Adults, As Merck Rival Nears Decision

Pfizer has the FDA approval it was seeking for Prevnar 20, the latest update to its blockbuster pneumococcal vaccination franchise, keeping it one step ahead of a competing shot from Merck & Co.

The US regulator has cleared the pneumococcal conjugate vaccine – which protects against 20 common strains of Streptococcus pneumoniae – for adults aged 18 or older, and it now goes to the Advisory Committee on Immunization Practices (ACIP) for a decision on how it should be used in practice.

Pneumococcal disease is caused by Streptococcus pneumoniae, and includes non-invasive illnesses like pneumonia, sinusitis and middle ear infections, as well as invasive diseases like meningitis.

Prevnar covers all 13 serotypes found in Pfizer's near-$6 billion Prevnar 13 product, plus another seven that are linked to invasive pneumococcal disease (IPD) and have been associated with high fatality rates, antibiotic resistance and meningitis.

All told, the 20 serotypes covered by the new vaccine account for more than half of the 250,000 cases of IPD reported each year in the US, according to Pfizer.

"Overall, the seven additional serotypes in Prevnar 20 account for approximately 40% of all pneumococcal disease cases and deaths in the US," said the drugmaker. Around 10,000 American adults a year die as a result of IPD.

Prevnar 20 is also being developed for use in children, where Prevnar 13 is a mainstay of routine vaccination schedules in the US, although that programme is further back in development isn't expected to be ready for market until early 2023.

Growth of Prevnar has been driven lately by use in adults, however, and it is here that Pfizer is facing a challenge from Merck and its V114 pneumococcal conjugate vaccine candidate.

The Prevnar 20 approval comes a few weeks ahead of an FDA decision on Merck's V114, which was granted a priority review by the regulator in January for the prevention of IPD in adults.

V114 covers 15 serotypes, so the jury is out on whether it will be a big challenger to Pfizer's well-established brand now that Prevnar 20 is becoming available.

In two phase 3 trials in adults reported last year, V114 stimulated immune responses to all serotypes in the shot. The studies included a booster shot with Merck's older polysaccharide-based Pneumovax 23 vaccine, which is still widely used in elderly people, and showed that the combination was protective in both the over-50 and under-50 adult age groups.

Merck seems to be a little ahead of Pfizer in the paediatric setting however, with a filing anticipated by the end of the year, setting up a possible approval and launch for V114 in children a few months earlier than Prevnar 20.

Also emerging from the wings is Vaxcyte, which has a 24-valent shot in early development and hopes to have initial clinical data from that programme in late 2022/early 2023.

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