Palbociclib, Pfizer's CDK4 / 6 inhibitor, has the priority of FDA approval

Source: US and Chinese drug sources on October 14, 2014, Pfizer today announced that its CDK4 / 6 inhibitor, palbociclib, as a first-line drug for ER positive and HER2 negative breast cancer, has obtained FDA's priority approval, and is ready to apply for listing with phase II clinical data Palbociclib has gained FDA breakthrough status, so there are few roadblocks on its way to market Palbociclib's annual peak sales are expected to be $3-6 billion Pfizer has few important products on the market in recent years, so it is in urgent need of such heavy drugs as palbociclib In a phase II trial called paloma-1, the median progression free survival of patients with ER positive, HER2 negative, locally advanced or metastatic breast cancer was extended from 7.5 months to 26.1 months in combination with letrozole, compared with the latter alone, but the interim analysis showed no improvement in the overall survival rate In February 2013, Pfizer carried out a three-phase clinical trial called paloma-2 with a total of 450 people In September 2013, Pfizer started another phase III clinical trial called paloma-3 with 417 participants to evaluate the efficacy and safety of the combination of palbociclib and fulvestrant compared with the latter alone The two experiments will take two or three years to finish CDK4 / 6 is an important regulatory protein of cell division cycle, which induces cell transformation from G1 to S phase In fact, CDK4 / 6 can not only stop cell division, but also kill the existing cancer cells Clinically, it has been observed that patients with lymphoid cancer, lung cancer and breast cancer use CDK4 / 6 inhibitors to reduce tumor size This is the additional treatment value that was not predicted at the beginning of the project Similar drugs from Lilly and Novartis are expected to be available around 2016-2017 In addition to breast cancer, CDK4 / 6 inhibitors are still in clinical trials of at least five other tumors, among which melanoma and lung cancer have some positive results Broad spectrum anticancer drugs such as palbociclib should be developed as soon as possible, but the development process of palbociclib is very tortuous, reflecting the impact of various uncertain factors in the process of innovative drug development on a project Palbociclib was first synthesized by park Davis scientists in 2001, but at that time, some CDK inhibitors were in clinical use Unfortunately, the selectivity of these early CDK inhibitors is not good, so the toxicity is very large, some of them can not reach the treatment dose The selectivity of palbociclib is good, but park Davis is not interested in this product because of the bad clinical record of other so-called CDK4 / 6 inhibitors Just in time, Pfizer acquired Park Davis, but Pfizer's main interest was Lipitor, and it didn't pay much attention to palbociclib In 2002, Pfizer acquired phamacia This time, there are more products competing for clinical development resources Pfizer didn't do a phase I clinical until 2004, but because the patients are mixed (various cancers, different stages), the curative effect is limited In 2007, UCLA scientists found that palbociclib was very effective for breast cancer, especially ER positive breast cancer in vitro, and found that it had synergistic effect with letrozole Almost at the same time, some basic research shows that some breast cancer is completely dependent on CDK4 Under these factors, Pfizer started the second phase of clinical practice of palbociclib in 2009 Palbociclib shows that positive outcomes have revolutionized the industry's view of this target Lilly directly jumped from phase I to phase III clinical Novartis's similar project started five years ago, and now it is also in phase III clinical Almost all the first drugs have experienced the experience of palbociclib At the beginning, no one believed that the development was delayed by various external factors After the success of the key experiment, everyone swarmed in It is almost impossible to predict which target will succeed in the end at the current level of science and technology, and diversification is the best way to invest