Novartis’ CDK 4/6 inhibitor ribociclib has been classed as a breakthrough therapy by the FDA, keeping it on course for an early approval in the US.
Ribociclib (also known as LEE011) has been given the status as a first-line treatment for hormone receptor-positive, HER2-negative advanced breast cancer, a patient population that remains in need of new treatment options.
Having breakthrough status speeds up the development and review of new drugs, and will be a boon to Novartis as it tries to catch-up with Pfizer, which launched the first CDK 4/6 inhibitor – Ibrance (palbociclib) last year. Some analysts have predicted that the class could eventually achieve sales of $10bn or more.
The US regulator made its decision on the strength of the MONALEESA-2 trial, which showed that ribociclib given in combination with Novartis’ hormone therapy Femara (letrozole) extended progression-free survival compared to letrozole alone in postmenopausal women with previously-untreated HR+/HER2- advanced breast cancer.
Novartis plans to make the results of that trial the basis of regulatory discussions for ribociclib’s use in this clinical setting, in a bid to make the drug available to patients “as quickly as possible”. The full data set from the trial is due to be presented at the European Society for Medical Oncology (ESMO) conference in October.
During Novartis’ interim results briefing last month the firm’s head of oncology, Bruno Strigini, indicated that filings could occur before the end of the year. While Ibrance has a clear lead in the US, that timeline could mean the launch of ribociclib could be quite close to that of Pfizer’s drug in Europe.
Pfizer already has first-line data in hand for Ibrance, so Novartis is playing catch-up on that front as well, but the Swiss group believes there is plenty of scope for ribociclib in “a very sizeable market”.
Novartis is carrying out trials of the drug in first-line settings in combination with AstraZeneca’s hormonal therapy Faslodex (fulvestrant), as well as in pre-menopausal women and in adjuvant and neoadjuvant treatment.
If approved, ribociclib will complement Femara as well as Novartis’ mTOR inhibitor Afinitor/Votubia (everolimus), which is also approved for HR+/HER2- breast cancer and brought in $1.6bn in sales last year.