* New cancer pill LEEO11 starts Phase III tests December
* Rival to Pfizer's highly anticipated palbociclib drug
* Points to early competition in potential blockbuster field
By Ben Hirschler
LONDON, Nov 22 (Reuters) - Novartis is hot on the heels of Pfizer in developing a promising new type of breast cancer drug that analysts believe could generate billions of dollars in annual sales.
The Swiss drugmaker, which has previously kept its research programme under wraps, revealed on Friday that its experimental pill LEE011 was set to enter final-stage Phase III clinical trials next month.
Pfizer's rival drug palbociclib - the first in the class - is already in Phase III testing, but Novartis' rapid progress means the U.S. group could face competition sooner than expected. Both drugs are pills and work by blocking two enzymes known as cyclin dependent kinases (CDK) 4 and 6.
The significance of the new targeted approach to fighting cancer was highlighted in April when U.S. regulators granted a "breakthrough therapy" designation to palbociclib, based on impressive results seen in mid-stage trials.
Palbociclib is widely seen by investors as Pfizer's most valuable compound in late-stage development and the company has started several new clinical trials to maximise its potential.
Analysts currently expect annual palbociclib sales of $1.9 billion by 2019, according to consensus estimates compiled by Thomson Reuters Pharma, and some think it could eventually sell $5 billion if it is approved for multiple cancer types.
Because Novartis has not previously revealed mid-stage clinical trial data for LEE011, analysts have not so far modelled sales forecasts for that product.
LEE011's rapid advance suggests that Novartis has stealthily accelerated its development programme and "snuck up from behind," according to Bernstein analyst Tim Anderson.
"Investors should therefore be aware that palbociclib could face competition sooner than anticipated," he wrote in a research note.
Eli Lilly also has a CDK 4/6 inhibitor in development but it is further behind the other two drug companies.
Novartis disclosed that LEE011 would progress into Phase III clinical testing in a statement ahead of an investor presentation later on Friday, in which it announced a $5 billion share buyback programme and highlighted the potential of several research projects.
Like palbociclib, LEE011 will be tested in combination with a standard drug, letrozole, in postmenopausal women undergoing treatment for advanced or metastatic breast cancer.
A total of 500 women are expected to be enrolled into the Phase III study of LEE011 and the trial is due to complete in November 2016, according to the U.S. National Institutes of Health's ClinicalTrials.gov website.
Also like Pfizer, Novartis is hoping to use its drug beyond breast cancer. The website reveals a total of 11 clinical trials for LEE011 at various development stages, four of which are in breast cancer. Other earlier-stage studies with LEE011 are looking at melanoma, lymphoma and paediatric cancers.
Advances in understanding the molecular and genetic basis of cancer means the disease is now a top priority for research teams at many pharmaceutical companies.
Cancer drugs are expected to be the top-selling therapy area in the coming years, with sales in developed markets forecast to reach between $74 billion and $84 billion by 2017, according to pharmaceutical information firm IMS Health.