Novartis edges closer to market, rival Ibrance with latest PhIII data update

Novartis ($NVS) is closing in on becoming the second Big Pharma to market in the major blockbuster CDK 4/6 space--after rival Pfizer ($PFE)--with positive late-stage survival data posted at the ESMO cancer conference this weekend.

The figures for LEE011 (a.k.a. ribociclib) showed its experimental med non-steroidal aromatase inhibitor, alongside its older aromatase inhibitor med Femara (letrozole), significantly extended progression-free survival (PFS) compared to Femara alone as a first-line treatment in postmenopausal women with hormone receptor positive, HR+/HER2- advanced or metastatic breast cancer.

The study had not reached the median PFS target (as so many of the drug treatment arm remained healthy), but the data from the Phase III Monaleesa-2 test did show the drug could reduce the risk of progression or death by 44% compared to Femara--while also showing significantly improved tumor shrinkage, as more than half of women with measurable disease saw their tumor size shrink by at least 30%.

There were however some high levels of AEs, including a large decline in white blood cells for some patients (although this was also seen in Ibrance studies), as well as an overall risk of an increase in toxicity--although it appears this still would clear benefit/risk protocols from regulators. 

The 44% lowering of progression or death compares with the 42% fall found in Pfizer’s Ibrance (palbociclib) in a similar late-stage test, which gained approval last year for certain forms of breast cancer.

It was the first in a new class of meds that work by inhibiting molecules, known as cyclin-dependent kinases (CDKs) 4 and 6, involved in promoting the growth of cancer cells. Novartis now looks likely to be second to market with its FDA breakthrough tagged med, with Lilly ($LLY) bringing up the rear with its CDK 4/6 inhibitor abemaciclib.

Both Ibrance and ribociclib are expected to be making blockbuster sales, with $1 billion in peak annual revenue slated for Novartis, while some analysts see nearly $6 billion for Pfizer’s med at peak. It is forecast to bring in around $2 billion this year alone.  

“We are excited about these strong results that show LEE011 has the potential to be an effective first-line treatment option that could improve outcomes for women with HR+/HER2- advanced breast cancer,” said Bruno Strigini, CEO of Novartis’ Oncology unit.

“Following the Breakthrough Therapy designation granted by the FDA in August of this year, we look forward to working closely with health authorities to bring a much needed new treatment option to these patients as quickly as possible.”

More survival data is yet to come, as the Swiss major said that: “Due to the significant extension of PFS and clinical benefit seen with LEE011, analysis of the PFS in Monaleesa-2 was stopped early in May 2016 as recommended by the Independent Data Monitoring Committee. Follow up to measure overall survival is ongoing.”