In the race to be first to get US approval for a pan-cancer liquid biopsy the field had narrowed to just two serious contenders: Roche and Guardant Health. On Friday the latter company won, and the FDA’s rubber-stamp should boost usage of the Guardant360 blood test.
The assay was already on sale in the US as a so-called lab-developed test, without official FDA oversight. Its formal approval for comprehensive genomic profiling – essentially picking out all the targetable mutations carried by any sort of solid tumour – gives Guardant the opportunity to get its test established as the reliable choice before other liquid biopsies get a pass from the regulator.
Many oncologists and researchers are somewhat sceptical of liquid biopsies, feeling that while they are faster and cheaper than surgical biopsy their accuracy is simply not as good (Liquid biopsies: the future of cancer diagnosis?, June 12, 2019). Guidelines published by Esmo and the National Comprehensive Cancer Network recommend their use only in cases where tumours are not suitable for biopsy, or where not enough tissue can be harvested. Up to 25% of cancer patients fall into these categories.
Crucially the FDA’s approval does not require that a doctor assess whether tissue biopsy is possible or not before using Guardant360. The approval could thus help persuade cancer organisations to recommend the blood test’s use in all patients.
It could also bring more payers on board, though the reimbursement situation for Guardant360 is already pretty good. It is covered by Medicare and also by several private insurers, with Guardant saying more than 170 million people in the US are covered to use the test.
While the approval for comprehensive genomic profiling is the important achievement, the FDA also issued a separate approval for Guardant360, as a simple companion diagnostic for Astrazeneca’s lung cancer drug Tagrisso.
Given that Roche is the world’s largest diagnostics company, and one that is unusually eager to obtain regulatory approval for its products, it is somewhat surprising that the company will come second at best in the far more important pan-cancer setting. FoundationOne Liquid, the pan-tumour blood test developed by Foundation Medicine before Roche acquired it in 2015, is filed with the FDA, and approval could come by the end of this year.
Another surprising laggard is Grail. The Illumina spin-out is spectacularly well funded, with venture investors having sunk more than $2bn into the group. Its Galleri test is in several huge cancer trials, but is not yet on sale, and the company has said nothing about regulatory filings.
Several other companies have pan-solid tumour tests in development and are serious about getting the FDA’s approval. Guardant will have to make the most of its first-mover advantage.
|Selected liquid biopsies – progress update|
|Company||Liquid biopsy||Type||Status in US||Company funding ($m)|
|Guardant Health||Guardant360||Pan-cancer; helps assign targeted therapy||Approved||$550m VC funding; floated in 2018, current MC $8.5bn|
|Lunar-1||Postsurgical, detects disease recurrence||Sold for research use only|
|Lunar-2||Screening for colon cancer||Clinical trials|
|Foundation Medicine (Roche)||FoundationOne Liquid||Pan-cancer; helps assign targeted therapy||Sold as LDT; submitted to FDA||$115m VC funding; bought by Roche for $2.5bn in 2015|
|Grail||Galleri||Pan-cancer; early detection and identification of tumour origin||FDA breakthrough device status||$2.1bn VC funding|
|Thrive Earlier Detection||CancerSeek||Pan-cancer; early detection||FDA breakthrough device status||$367m VC funding|
|Natera||Signatera||Pan-cancer; postsurgical, detects disease recurrence||FDA breakthrough device status||$152m VC funding; floated in 2015, current MC $4.2bn|
|Archer DX||Stratafide||Pan-cancer; helps assign targeted therapy||FDA breakthrough device status||$150m VC funding; bought by Invitae in 2020 for $1.5bn|
|Source: EvaluateMedTech & company websites.|