Clinical Trials Arena

Merck to start trials investigating single dosing regimen of HPV vaccine

The two trials will evaluate alternative dosing regimens for Gardasil 9 vaccine compared to the currently approved three-dose regimen.

Merck & Co (MSD) plans to start two prospective clinical trials evaluating the safety and efficacy of a single-dose regimen of its multivalent human papillomavirus (HPV) vaccine, Gardasil 9 (recombinant Human Papillomavirus 9-valent).

The company plans to conduct two separate trials investigating Gardasil 9 in men and women aged 16-26 years to evaluate whether a single dose of the vaccine provides comparable long-term protection, compared to the approved three-dose regimen. The study is expected to start enrolment in Q4 of this year.

Gardasil 9 was approved by the US Food and Drug Administration (FDA) to prevent certain cancers, such as cervical, anal, oropharyngeal, and head and neck cancers, caused by nine different HPV types in 2014. The vaccine is indicated for individuals aged 9-45 years. It is administered in a three-dose schedule for people aged 15-45 years but it can be given in a two or three-dose schedule for children aged 9-14 years.

The vaccine coverage for HPV remains low worldwide. As per the World Health Organization’s (WHO) latest vaccine coverage statistics, global coverage by full dose in 2022 was 15% and 5% in females and males, respectively. First dosage coverage was higher at 21% and 6% in females and males, respectively, during the same period.

In a push to boost coverage, the WHO updated its scheduling recommendations in December 2022. The new recommendations say that one dose of vaccine can adequately protect women aged 9-14 years against cervical cancer caused by HPV, specifically, HPV 16 and HPV 18 strains.

The push to increase coverage has also increased the demand for Gardasil 9 by 29%, generating $8.9bn in global sales in 2023, as per MSD’s financials. GlobalData expects the vaccine to continue its upward sales trajectory and pull in over $12.2bn in global sales in 2029.

GlobalData is the parent company of Clinical Trials Arena.

MSD is also developing newer versions of Gardasil developed using proprietary virus-like particle (VLP) technology to expand the coverage of the HPV vaccine. The newer Gardasil was developed to have more impact on individuals of African and Asian descent. A Phase I trial for this version is planned to start in Q4 2024.