LTFU: Long-term follow up of subjects participating in the clinical trials of the HPV-vaccine

LTFU evaluates the long-term effectiveness, immunogenocity and safety of the HPV-vaccines Gardasil and Gardasil-9.

Published: 23.11.2017, updated: 23.11.2017

 

The Cancer Registry of Norway is coordinating two LTFU-projects. The projects are similar in regards to research objective and method, but follow different study participants in two groups. The participants have respectively taken part in the clinical trials of the HPV-vaccines Gardasil and Gardasil-9.

The American Food and Drug Administration (FDA) recognized the Nordic countries as prime locations for implementing the LTFU-studies, because of the high standard of the health registries in Denmark, Iceland, Norway and Sweden. Thus, they instructed the vaccine producer Merck/MSD to carry out the LTFU-studies in the Nordic region.

The aim of the studies is to evaluate the duration, safety and protective attributes of the vaccines. 

 

Long-term follow up through health registries

In 2002, approximately 5500 young Nordic women participated in the clinical trial of the HPV-vaccine Gardasil, The FUTURE II-study. 1698 of these women, were Norwegian participants.

Approximately half of the women received the vaccine, while the other half were given a placebo. The women in the placebo-group were offered the HPV-vaccine after study termination. The women will be followed passively by the Cancer Registry of Norway through health registries until 2020.

From 2007 - 2013, 637 Norwegian women participated in the clinical trial of Gardasil-9. Approximately half were given Gardasil-9, while the other half reseived Gardasil. The women in this cohort will be followed passively by the Cancer Registry of Norway through health registries until 2028. 

The LTFU-projects follow the study participants to evaluate the effectiveness, immunogenocity and safety of the vaccines. The Cancer Registry of Norway collects information about HPV-related lesions in the cervix, vulva and vagina among study participants. 

Safety is assesed by collecting data from the Norwegian Patient Registry.

Levels of vaccine-induced antibodies in the blood 5 and 10 years after vaccination, provides an estimate of the protective qualities of the vaccine over time. 

 

High effectiveness in both vaccines

Approximately 90% of cervical cancer cases are caused by high-risk HPV-types 16, 18, 31, 33, 45, 52 and 58. 

The FUTURE II-study could show that Gardasil was measured to be >98% effective against high-risk HPV-types 16 and 18. A recent study also concluded that Gardasils protective effectiveness remained above 90% for at least 10 years. 

Gardasil-9 provides protection against all 7 high-risk HPV-types. Both vaccines provides protection against HPV-types 6 and 11, which cause approximately 90% of all genital wart cases. 

Gardasil-9 has also proven to be an effective and safe vaccine. A study published in february 2015, could show that the vaccine gave 97% protection against precancerous conditions cause by HPV-types 31, 33, 45, 52 and 58.

 

Collaboration and implementation

The LTFU-studies are a collaborative project with the Cancer Registry of Norway, Karolinska Institute in Sweden, the Danish Cancer Society and the Icelandic Cancer Registry. The Cancer Registry of Norway is the Nordic coordination center (NCC) in the studies, playing a central role in the collection and distribution of data and samples. 

The vaccineproducer Merck & Co., Inc. has funded the LTFU-projects.

 

Project affiliations

Mari Nygård, Giske Ursin, Sophie Berger, Espen Enerly, Suzanne Campbell, Kristina Stormo Gjøtterud, Ragnhild Flingtorp, Bo Terning Hansen og Line Ragna Aakre Karlsson. 

 

The Norwegian Institute of Public Health administer the HPV-vaccine.