HTG EdgeSeq ALKPlus Assay EU (HTG Molecular Diagnostics) is an in vitro diagnostic assay which is designed to identify the ALK status of NSCLC. It is a next-generation sequencing (NGS)-based assay that works with the company's HTG EdgeSeq analyser. The test is only compatible with Illumina MiSeq and MiSeqDx systems. The test is done on stored formalin-fixed, paraffin-embedded (FFPE) lung tumour specimens.
The test differs from current methods of ALK status testing in that it automatically generates a report on ALK status. The report is presented in a way that needs no special training or experience to understand.
The NICE guideline on lung cancer recommends that ALK status testing should be done for all people with non-squamous NSCLC at diagnosis, because the mutation is more common in this subgroup.
ALK status testing is done through fluorescence in situ hybridisation (FISH), immunohistochemistry, chromogenic in situ hybridisation and reverse transcription polymerase chain reaction (RT‑PCR).
HTG EdgeSeq ALKPlus Assay EU would be used in secondary or tertiary care clinical laboratories and run by qualified laboratory staff with appropriate training.
People with non-squamous NSCLC are most likely to have ALK fusions, as well as people with squamous NSCLC that show the characteristics of being ALK positive (for example, younger people or those who don't smoke). The company estimates that approximately 50,000 people have ALK status testing each year.
The company states that each test with HTG EdgeSeq ALKPlus Assay EU costs £250 to £300. Upkeep of the HTG EdgeSeq analyser costs about £10,000 per year. Most laboratories will also need to purchase a compatible Illumina MiSeq or MiSeqDx system.
HTG EdgeSeq ALKPlus Assay EU is not widely used in UK practice.
It can only be used with both an HTG EdgeSeq system and compatible lllumina MiSeq or MiSeqDx analyser. Specialist commentators estimate that around 25% of centres that test ALK status will have access to a MiSeq or MiSeqDx analyser.
The test produces a report which can be interpreted by any clinician, not just trained specialists.