Roche’s Cobas PIK3CA Mutation Test – A Blessing for Breast Cancer Patients

On 15th December, Roche announced the launch of the cobas® PIK3CA Mutation Test for patients with advanced or metastatic breast cancer. Breast cancer can be triggered by a variety of mutations on different sets of genes, some of which are challenging to detect or treat. A mutation on phosphoinositide 3-kinase (PI3K) is one of those recalcitrant gene mutations that are difficult for both test and control.

“Nearly two million women are diagnosed with breast cancer each year, and an estimated half a million could harbor a PIK3CA [(phosphoinositide 3-kinase, catalytic, alpha subunit)] mutation. If correctly identified, some of these women may benefit from targeted therapy,” said Thomas Schinecker, CEO Roche Diagnostics. “We are pleased to offer the cobas PIK3CA Mutation Test CE-IVD, enabling clinicians to accurately and quickly manage their breast cancer patients.”

Competitions Among Pharma Giants

After other pharma giants including Roche failed and abandoned similar research, Swiss-based Novartis succeeded in tackling difficult to treat breast cancer with PIK3CA mutations in August 2018 and outcompeted the relatively unsafe Zydelig (idelalisib) from Gilead Sciences. According to Samit Hirawat, head of Novartis’ oncology global drug development, “[alpelisib] is the only alpha-specific PI3K inhibitor and the first one to show potential increased benefit and acceptable tolerability for patients.”

With a total enrollment of 572 patients, Novartis’ global Phase 3 SOLAR-1 trial evaluated the alpha-specific PI3K inhibitor, alpelisib, had met the primary endpoint of progression-free survival (PFS). The clinical trial demonstrated the combo of alpelisib and AstraZeneca’s hormonal therapy Faslodex (fulvestrant) showed a more promising efficacy than Faslodex only in postmenopausal women and men with hormone-receptor-positive PIK3CA-mutant advanced or metastatic breast cancer.

Adverse events in this trial were consistent with those observed in previous studies. The secondary endpoints included overall survival, overall response rate, clinical benefit rate, health-related quality of life, and efficacy. Alpelisib finally received approval in May 2019, along with Novartis’ screening tool PIK3CA RGQ PCR Kit, which detects the PIK3CA mutation in a tissue and/or a liquid biopsy.

Roche has now entered the fray with its cobas PIK3CA mutation test for patients with advanced or metastatic breast cancer. Previously available as research use only (RUO), the in vitro diagnostic (IVD) test is now available in countries accepting the CE mark, This new test kit not only adds a new diagnostic option to a challengingly detected breast cancer mutation but allows “fast time-to-results” in less than eight hours.

Cobas PIK3CA Mutation Test

The cobas PIK3CA Mutation Test (CE-IVD) is a real-time polymerase chain reaction (PCR) test that qualitatively detects and identifies 17 mutations in exons 2, 5, 8, 10, and 21 within the gene encoding for the catalytic subunit of PIK3CA in DNA isolation from formalin-fixed paraffin-embedded tumor tissue (FFPET).

Each of these kits includes liquid, ready-to-use reagents for increased laboratory efficiency, with the capability of processing up to 30 samples per run. Each sample is processed with the cobas DNA sample preparation kit, which helps isolate genomic DNA from FFPET human specimens, followed by PCR analysis with the cobas z 480 Analyzer for automated amplification and mutation detection. The benefits of the test are not just convenience and time-saving, but high sensitivity of 0.7%-3.5% mutation level (variant-dependent), clinical reproducibility of >99%, sample input from a single 5μm FFPET section with >10% tumor, as well as repeatability of 99.7% shown over multiple specimens, reagent lots, operators, and days.

By Judy Ya-Hsuan Lin

Related Article: Spotlight: Novartis’ Kisqali Shows Promising Results in Metastatic Breast Cancer

References

1. https://www.roche.com/media/releases/med-cor-2020-12-15.htm?fbclid=IwAR2hhV32bXTg2WgKolubwK08Ypw4IeMWf8Jfv7_Gjj3IPfacP76gKrmFd7I

Author

Judy Ya-Hsuan Lin

Success is the ability to go from one failure to another with no loss of enthusiasm.