Wednesday, May 14, 2014
Palbociclib appears to prolong progression-free survival in women with metastatic breast cancer
Researchers at the annual AACR meeting announced the results of a clinical trial of a new drug with activity in some forms of breast cancer. Palbociclib (PD-0332991), a pill developed by Pfizer, was tested in women with metastatic breast cancer cells with estrogen receptors and lacking Her2. These ER+/Her2- tumors represent the most common breast cancer subtype, which is 1 reason so many people are eying the results of this relatively small, randomized study.
The phase 2 trial, called PALOMA-1 included 165 post-menopausal women with advanced ER+/Her2 negative disease. The research subjects were assigned to take either Letrazole (Femara, an aromatase inhibitor, a drug that inhibits estrogen synthesis) alone, or Letrazole and also the experimental drug, Palbociclib. The study found a highly significant difference in progression free survival (PFS), the intended endpoint: the mean time until disease progressed was 20.2 months among women who took Palbociclib, as opposed to 10.2 months for those assigned to Letrazole alone. The p-value for the difference between the arms (1-sided) was 0.0004. That’s a powerful result.
But there was no statistically significant difference in overall survival between the 2 groups, a fact that was irksome to some observers, particularly in the biotech investment world, and to some who were reminded of the Avastin story and its fall-out. Most of the women lived for approximately 3 years after enrolling, with a trend of a few months favoring the Palbociclib arm. Another problem is that more than half the patients were recruited to the study based on biomarker results, having to do with cyclin D1 amplification and/or loss of p16. So it could be the results are more relevant to breast cancer patients who have those particular changes. How those molecular features, enriched in the final study population, relate to Palbociclib’s usefulness in breast cancer and other tumor types warrants more evaluation, for sure.
My feeling is that this may prove to be a useful drug, not just in breast cancer. Any medication which interferes with cell growth by blocking cyclin-dependent kinases (enzymes) called CDK-4 and -6 could be useful in quite a few malignancies. The main side effect was suppression of the bone marrow (low blood cells). Some questions I’d like to ask the researchers, and which I hope they’ll address in the Phase III study, is if certain types of mets (e.g. lung vs. bone) or certain molecular subtypes are more tempered by this drug.
As for 10 months of progression-free survival, if it pans out in a formal, published work, that’s valuable. Imagine that you’re 55 years old and living with metastatic breast cancer. A drug that is likely to delay, by most of 2 years, your tumor’s expansion into the lungs (causing shortness of breath), or bones (causing fractures and pain) or liver, and elsewhere can be worth a lot. It’s about the quality of life, whether or not it’s extended.
One final concern is that this study wasn’t blinded, so the doctors’ assessment of how the patients were doing, and the patients’ assessment of how they were feeling, may have been influenced by their knowing which arm they were on. Also, because this new drug is a pill, some insurance may not cover it, a policy issue that applies to many new cancer drugs.
This post originally appeared at Medical Lessons, written by Elaine Schattner, MD, ACP Member, a nonpracticing hematologist and oncologist who teaches at Weill Cornell Medical College, where she is a Clinical Associate Professor of Medicine. She shares her ideas on education, ethics in medicine, health care news and culture. Her views on medicine are informed by her past experiences in caring for patients, as a researcher in cancer immunology and as a patient who's had breast cancer.
Contact ACP Internist
Send comments to ACP Internist staff at email@example.com.
- Sued for medical malpractice--again
- QD: News Every Day--Low-value services may cost Me...
- Europe's take on America's statins guidelines
- Candida CAUTI: An oxymoron
- QD: News Every Day--Minimum exercise levels may no...
- Is it health care or beyond?
- QD: News Every Day--This 'snack' might boost glyce...
- Things that frustrate physicians and harm patients...
- QD: News Every Day--Pictures on prescriptions may ...
- What I would do if my foot caught fire
Members of the American College of Physicians contribute posts from their own sites to ACP Internistand ACP Hospitalist. Contributors include:
Albert Fuchs, MD, FACP, graduated from the University of California, Los Angeles School of Medicine, where he also did his internal medicine training. Certified by the American Board of Internal Medicine, Dr. Fuchs spent three years as a full-time faculty member at UCLA School of Medicine before opening his private practice in Beverly Hills in 2000.
And Thus, It Begins
Amanda Xi, ACP Medical Student Member, is a first-year medical student at the OUWB School of Medicine, charter class of 2015, in Rochester, Mich., from which she which chronicles her journey through medical training from day 1 of medical school.
Ira S. Nash, MD, FACP, is the senior vice president and executive director of the North Shore-LIJ Medical Group, and a professor of Cardiology and Population Health at Hofstra North Shore-LIJ School of Medicine. He is Board Certified in Internal Medicine and Cardiovascular Diseases and was in the private practice of cardiology before joining the full-time faculty of Massachusetts General Hospital.
Zackary Berger, MD, ACP Member, is a primary care doctor and general internist in the Division of General Internal Medicine at Johns Hopkins. His research interests include doctor-patient communication, bioethics, and systematic reviews.
Controversies in Hospital
Run by three ACP Fellows, this blog ponders vexing issues in infection prevention and control, inside and outside the hospital. Daniel J Diekema, MD, FACP, practices infectious diseases, clinical microbiology, and hospital epidemiology in Iowa City, Iowa, splitting time between seeing patients with infectious diseases, diagnosing infections in the microbiology laboratory, and trying to prevent infections in the hospital. Michael B. Edmond, MD, FACP, is a hospital epidemiologist in Iowa City, IA, with a focus on understanding why infections occur in the hospital and ways to prevent these infections, and sees patients in the inpatient and outpatient settings. Eli N. Perencevich, MD, ACP Member, is an infectious disease physician and epidemiologist in Iowa City, Iowa, who studies methods to halt the spread of resistant bacteria in our hospitals (including novel ways to get everyone to wash their hands).
db's Medical Rants
Robert M. Centor, MD, FACP, contributes short essays contemplating medicine and the health care system.
Suneel Dhand, MD, ACP Member
Suneel Dhand, MD, ACP Member, is a practicing physician in Massachusetts. He has published numerous articles in clinical medicine, covering a wide range of specialty areas including; pulmonology, cardiology, endocrinology, hematology, and infectious disease. He has also authored chapters in the prestigious "5-Minute Clinical Consult" medical textbook. His other clinical interests include quality improvement, hospital safety, hospital utilization, and the use of technology in health care.
Juliet K. Mavromatis, MD, FACP, provides a conversation about health topics for patients and health professionals.
Dr. Mintz' Blog
Matthew Mintz, MD, FACP, has practiced internal medicine for more than a decade and is an Associate Professor of Medicine at an academic medical center on the East Coast. His time is split between teaching medical students and residents, and caring for patients.
Toni Brayer, MD, FACP, blogs about the rapid changes in science, medicine, health and healing in the 21st century.
Vineet Arora, MD, FACP, is Associate Program Director for the Internal Medicine Residency and Assistant Dean of Scholarship & Discovery at the Pritzker School of Medicine for the University of Chicago. Her education and research focus is on resident duty hours, patient handoffs, medical professionalism, and quality of hospital care. She is also an academic hospitalist.
John H. Schumann, MD, FACP, provides transparency on the workings of medical practice and the complexities of hospital care, illuminates the emotional and cognitive aspects of caregiving and decision-making from the perspective of an active primary care physician, and offers behind-the-scenes portraits of hospital sanctums and the people who inhabit them.
Ryan Madanick, MD, ACP Member, is a gastroenterologist at the University of North Carolina School of Medicine, and the Program Director for the GI & Hepatology Fellowship Program. He specializes in diseases of the esophagus, with a strong interest in the diagnosis and treatment of patients who have difficult-to-manage esophageal problems such as refractory GERD, heartburn, and chest pain.
Mike Aref, MD, PhD, FACP, is an academic hospitalist with an interest in basic and clinical science and education, with interests in noninvasive monitoring and diagnostic testing using novel bedside imaging modalities, diagnostic reasoning, medical informatics, new medical education modalities, pre-code/code management, palliative care, patient-physician communication, quality improvement, and quantitative biomedical imaging.
William Hersh, MD, FACP, Professor and Chair, Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, posts his thoughts on various topics related to biomedical and health informatics.
David Katz, MD
David L. Katz, MD, MPH, FACP, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care.
Richard Just, MD, ACP Member, has 36 years in clinical practice of hematology and medical oncology. His blog is a joint publication with Gregg Masters, MPH.
Kevin Pho, MD, ACP Member, offers one of the Web's definitive sites for influential health commentary.
Michael Kirsch, MD, FACP, addresses the joys and challenges of medical practice, including controversies in the doctor-patient relationship, medical ethics and measuring medical quality. When he's not writing, he's performing colonoscopies.
Elaine Schattner, MD, FACP, shares her ideas on education, ethics in medicine, health care news and culture. Her views on medicine are informed by her past experiences in caring for patients, as a researcher in cancer immunology, and as a patient who's had breast cancer.
Mired in MedEd
Alexander M. Djuricich, MD, FACP, is the Associate Dean for Continuing Medical Education (CME), and a Program Director in Medicine-Pediatrics at the Indiana University School of Medicine in Indianapolis, where he blogs about medical education.
Rob Lamberts, MD, ACP Member, a med-peds and general practice internist, returns with "volume 2" of his personal musings about medicine, life, armadillos and Sasquatch at More Musings (of a Distractible Kind).
David M. Sack, MD, FACP, practices general gastroenterology at a small community hospital in Connecticut. His blog is a series of musings on medicine, medical care, the health care system and medical ethics, in no particular order.
Reflections of a Grady
Kimberly Manning, MD, FACP, reflects on the personal side of being a doctor in a community hospital in Atlanta.
The Blog of Paul Sufka
Paul Sufka, MD, ACP Member, is a board certified rheumatologist in St. Paul, Minn. He was a chief resident in internal medicine with the University of Minnesota and then completed his fellowship training in rheumatology in June 2011 at the University of Minnesota Department of Rheumatology. His interests include the use of technology in medicine.
Technology in (Medical)
Neil Mehta, MBBS, MS, FACP, is interested in use of technology in education, social media and networking, practice management and evidence-based medicine tools, personal information and knowledge management.
Peter A. Lipson,
Peter A. Lipson, MD, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. The blog, which has been around in various forms since 2007, offers musings on the intersection of science, medicine, and culture.
Why is American Health Care So Expensive?
Janice Boughton, MD, FACP, practiced internal medicine for 20 years before adopting a career in hospital and primary care medicine as a locum tenens physician. She lives in Idaho when not traveling.
World's Best Site
Daniel Ginsberg, MD, FACP, is an internal medicine physician who has avidly applied computers to medicine since 1986, when he first wrote medically oriented computer programs. He is in practice in Tacoma, Washington.
Other blogs of note:
American Journal of
Also known as the Green Journal, the American Journal of Medicine publishes original clinical articles of interest to physicians in internal medicine and its subspecialities, both in academia and community-based practice.
A collaborative medical blog started by Neil Shapiro, MD, ACP Member, associate program director at New York University Medical Center's internal medicine residency program. Faculty, residents and students contribute case studies, mystery quizzes, news, commentary and more.
Michael Benjamin, MD, ACP member, doesn't accept industry money so he can create an independent, clinician-reviewed space on the Internet for physicians to report and comment on the medical news of the day.
The Public Library of Science's open access materials include a blog.
One of the most popular anonymous blogs written by an emergency room physician.