How are Companion Diagnostics Considered in Economic Evaluations of Oncology Treatments? A Review of Health Technology Assessments

BACKGROUND

Companion diagnostic (CDx) testing is increasingly used to identify eligible patients for targeted treatments. Guidance on how CDx testing should be incorporated into cost-effectiveness models (CEM) is limited. This review evaluated how health technology assessment bodies and research organizations considered CDx in CEMs of targeted therapies in oncology and whether this ultimately impacted their decisions or time from regulatory approval to recommendations.

METHODS

An exhaustive list of approved CDx tests in oncology was compiled. For corresponding indications and treatments, NICE appraisals published between 2016 and 2019 were identified. Then, assessments for the same treatments issued from 11 other agencies were reviewed. Data extracted included background and CDx information, CDx's role in the CEM, and recommendations.

RESULTS

Twenty-seven NICE appraisals were identified; 15 considered CDx testing in the CEM, while 12 did not, mainly because testing had already been established for the comparators within the same class or in clinical practice from a prior treatment line. Both testing costs and mutation prevalence drove CDx testing costs per patient. The cross-comparison of assessments showed that CDx test characteristics were inconsistently reported. Time from regulatory approval to recommendations was not impacted by CDx cost inclusion in CEMs.

CONCLUSION

CDx testing was included in cost-effectiveness models whenever mutation testing was required solely for patients receiving targeted treatment; cost per patient was based on test costs and mutation prevalence. It is unclear if expanded reliance on CDx testing will impact future assessments of targeted therapies. A future update is warranted to track trends over time.

The diversity of microsporidian parasites infecting the Holarctic amphipod Gammarus lacustris from the Baikal region is dominated by the genus Dictyocoela

Microsporidia are a highly diverse group of single-celled eukaryotic parasites related to fungi and infecting hosts belonging to all groups of eukaryotes, including some protists, invertebrate and vertebrate animals. We investigated the diversity of microsporidia in the Holarctic amphipod species Gammarus lacustris from mostly, but not limited to, water bodies in the Lake Baikal region. Ribosomal DNA sequencing and host transcriptome sequencing data from various works show that this species is predominantly infected by representatives of the genus Dictyocoela and probably has some features underlying this specific interaction.

Genetic diversity of Microsporidia in the circulatory system of endemic amphipods from different locations and depths of ancient Lake Baikal

Endemic amphipods (Amphipoda, Crustacea) of the most ancient and large freshwater Lake Baikal (Siberia, Russia) are a highly diverse group comprising >15% of all known species of continental amphipods. The extensive endemic biodiversity of Baikal amphipods provides the unique opportunity to study interactions and possible coevolution of this group and their parasites, such as Microsporidia. In this study, we investigated microsporidian diversity in the circulatory system of 22 endemic species of amphipods inhabiting littoral, sublittoral and deep-water zones in all three basins of Lake Baikal. Using molecular genetic techniques, we found microsporidian DNA in two littoral (Eulimnogammarus verrucosus, Eulimnogammarus cyaneus), two littoral/sublittoral (Pallasea cancellus, Eulimnogammarus marituji) and two sublittoral/deep-water (Acanthogammarus lappaceus longispinus, Acanthogammarus victorii maculosus) endemic species. Twenty sequences of the small subunit ribosomal (SSU) rDNA were obtained from the haemolymph of the six endemic amphipod species sampled from 0–60 m depths at the Southern Lake Baikal’s basin (only the Western shore) and at the Central Baikal. They form clusters with similarity to Enterocytospora, Cucumispora, Dictyocoela, and several unassigned Microsporidia sequences, respectively. Our sequence data show similarity to previously identified microsporidian DNA from inhabitants of both Lake Baikal and other water reservoirs. The results of our study suggest that the genetic diversity of Microsporidia in haemolymph of endemic amphipods from Lake Baikal does not correlate with host species, geographic location or depth factors but is homogeneously diverse.