Genetic profiling is feasible in patients with rare cancers, with more than half having actionable findings that may lead to treatment with a drug matched to the biomarker, according to an Australian study.
Results from the NOMINATOR (GeNOmic MatchINg TreATment fOr Rare Cancers) study were presented at the COSA 2020 virtual meeting by Dr Damien Kee, a medical oncologist at Peter MacCallum Cancer Centre, Melbourne.
The study recruited 121 patients with rare cancers, most of whom ( 91%) had advanced stage disease. After tumour and blood samples were analysed by Next Generation Sequencing (NGS) for a panel of 386 genes, 56% of the 100 patients with sequencing results were found to have at least one biomarker predictive of response to a drug.
The most common actionable genes were CDKN2a/B, PTEN, NF1 KRAS and PIK3CA mutations, and 27% of patients had findings that were defined as high impact.
Dr Kee told the meeting that after a follow up of more than 12 months, 13 of 94 patients with advanced disease had received one or more lines of genomically matched treatment and 57 had received unmatched treatment.
This corresponded to one in four patients with an identified genomic biomarker receiving a matched drug treatment, he said.
For instance, one patient with a uterine PECOMA found to have BRCA2. MSH2 and MSH6 biomarkers received matched treatment with olaparib and durvalumab for more than 18 months part of the MoST trial.
All six patients with the highest level findings (OncKB 1) were able to access treatment via the PBS or via self funding or pharma programs. However only 11-13% of those with lower level impact findings were able to access a matched drug treatment.
Genomic sequencing also led to a change of diagnosis for six patients, including four with soft tissue sarcomas who were found to have a NF1 mutant melanoma and were able to access PBS-funded treatment.
Survival outcomes were not different for patients who received matched treatment compared to no treatment, but Dr Kee said the findings were descriptive only because they came from patients with advanced stage cancers who entered the study at the end of their disease course.
Australian Rare Cancer Portal
Two of the key challenges for the future will be to shift to early genomic sequencing and to access matched treatment early in the course of disease, Dr Kee predicted.
“Drug access need to be improved to realise the potential benefits of sequencing,” he said.
“This could be improved by more biomarker-driven trials that include rare cancer or pan-cancer cohorts, or pharmaceutical access programs open towards generating data in new tumour types.”
Dr Kee said another key requirement for the future is the need to continue to collect and share data in rare cancer to help build the evidence base. He pointed to the rare cancer networks such as the Australian Rare Cancer Portal (arcportal.org.au).
In a separate presentation at COSA 2020, Hobart-based medical oncologist Dr Rebecca Tay described the portal as an online platform that will provide cancer specialists with a single point of access to clinical guidance via a national network of rare cancer expertise.
“By referring your patient to the ARC Portal our team can facilitate an expert opinion or clinical advice from a Rare Cancer Expert; advice on germline or molecular testing options and interpretation; identify relevant guidelines [and] enrolment in rare cancer research,” she said.
The ARC Portal will also streamline collaborative rare cancer research by using curated rare cancer clinical outcome and genomic data paired with access to relevant biospecimen samples, said Dr Tay.
The portal also aims to ensure equitable patient access to rare cancer expertise and research with an approved overarching remote patient informed consent process.