In light of promising results conducted by an independent data monitoring committee, Pfizer's newest treatment IBRANCE (Palbociclib) ended clinical trials early this week as phase 3 of the trials ended demonstrating improvement in progression-free survival in women who had undergone treatment for metastatic breast cancer. 

Though metastatic breast cancers are often difficult to treat, and show some of the highest levels of resurfacing during or after hormone therapy, Pfizer announced today that IBRANCE in collaboration with "Fulvestrant" significantly altered survival rates when compared to Fulvestrant with a placebo. Approved already by the U.S. Food and Drug Administration (FDA) for accelerated use on account of its preliminary findings, the drug was released in limited quantities in February 2015 as a first-line treatment for women with metastatic ER+/HER2- breast cancer. 

"The results of this trial are especially important because they help us understand the potential of IBRANCE to improve outcomes in patients with this difficult to treat cancer" Senior Vice President of Clinical Development and Medical Affairs for Pfizer, Dr. Mace Rothenberg says. "We're gratified to be able to stop the trial early and are engaging in discussion with health authorities regarding a regulatory path forward."

But that doesn't mean that the drug comes without its fair share of potential side effects, as well.  In fact, amongst the long list that Pfizer recently released, the top common complications with IBRANCE were neutropenia, infections and pulmonary embolisms when taken in conjuction with Letrozole (5%), and based on the drugs mechanism of action IBRANCE can also cause serious fetal harm. 

However, with such impressive preliminary results, many physicians may support Pfizer claiming the common side effects well worth the risk.

And for Pfizer, all the hassle and red tape may also be worth the risk for this novel new treatment. Priced at $9,850 for a month's supply of pills, analysts with NASDAQ estimate that the new treatment alone could generate up to $4 billion in sales in 2020 for the pharmaceutical company. And they won't be the only ones making a pretty penny off of the deal either. Because IBRANCE is taken in combination with "Fulvestrant", a generic of Faslodex made by AstraZeneca PLC, you can expect that they will be claiming a piece of the billions, as well.