Pfizer plots Ibrance expansion as early-stage breast cancer trial begins

Pfizer's ($PFE) new breast-cancer-fighter, Ibrance, has gotten off to a quick start in patients with advanced breast cancer. And now, the company is embarking on a study to see whether it can work earlier in the disease, too.

The pharma giant is testing the drug--the first in the new CD4/6 inhibitor class to hit the market--in early-stage patients with tumors that are estrogen-receptor-positive but HER2-negative. An estimated 4,600 participants--premenopausal and postmenopausal women, as well as men who have had stage 2 or 3 forms of the cancer--will receive either solo standard hormonal therapy or hormonal therapy plus Ibrance for at least 5 years.

The goal is to rack up new indications for the newcomer, which in February won a speedy FDA blessing to combat advanced, hormone-positive breast cancer in the first-line setting.

But that's not to say Ibrance hasn't been turning out impressive sales with the indication it's already bagged. About 3,000 prescribers are already writing Ibrance scripts, up from 800 at the end of March, CEO Ian Read said recently on the Pfizer's Q2 earnings conference call. First-line market share more than doubled in the period to reach 22%, delivering a $140 million performance that helped boost Pfizer's overall oncology sales by 36%.

With those figures in mind, Leerink Partners analyst Seamus Fernandez, for one, hiked his Ibrance sales estimate to $710 million for the year--a big increase on his earlier prediction of $400 million.

Pfizer's Albert Bourla

And if Pfizer's label-expansion efforts prove fruitful, those forecasts will only head upward. In addition to the early-stage study, the company is embarking on a trial examining Ibrance as a treatment for head and neck cancer, as well as prepping a Phase II examination of Ibrance plus Abraxane in advanced pancreatic cancer, oncology chief Albert Bourla said on the Q2 call. And back in May, the company said it had cut short its PALOMA-3 trial thanks to impressive second-line data for the therapy in patients with metastatic breast cancer.

- get the release from Pfizer

Special Report: The top 15 pharma companies by 2014 revenue - Pfizer