By Dr. Kevin Williams
Chief Medical Officer for Rare Disease at Pfizer
The “Ask Dr. Kevin” series is brought to you by Pfizer Rare Disease in collaboration with the National Newspaper Publishers Association (NNPA) to increase understanding of sickle cell disease.
As you may have heard, my team at Pfizer recently experienced a significant disappointment. Our phase three trial for rivipansel, a potential treatment for the debilitating vaso-occlusive crises (VOCs) endured by virtually every person with sickle cell disease (SCD), did not meet its study endpoints. Both professionally and personally, this news was hard to hear, especially knowing that people with SCD have such limited treatment options available to them. However, even though the study didn’t turn out as we had hoped, the good news is that the rivipansel program greatly advanced our understanding of SCD and VOCs, which will be important for future SCD research programs and drug development.
As I’ve written about before, SCD is the most common inherited blood disorder, and it disproportionately affects people of African descent[i]. VOCs, one of the most common complications of SCD, are marked by extreme pain resulting from sickle-shaped red blood cells clumping together in the bloodstream[ii]. The standard of care for patients experiencing these pain crises has remained largely unchanged since the first report of SCD in 1910, and is restricted mostly to treating disease symptoms, like the use of opioids for pain management. Just last month, Novartis was granted FDA approval for a treatment to reduce the frequency of VOCs experienced by patients; however, there still stands a greater need for therapies that target the root cause of these painful episodes.
The clinical trial for rivipansel may have come to an end; however, the one thing that working in SCD and collaborating with the NNPA and SCD-focused patient groups over the last several years has taught me is that this community is strong. Their strength inspires me and my team every day and fuels our passion for our work in advancing the scientific research of rare diseases like SCD.
In this article, I’d like to share a little more about the importance of innovation in rare diseases and answer some common questions about the role clinical trials play as the foundation for moving medical innovation forward.
Why are clinical trials important?
Cutting-edge research and clinical trials are key to making an impact for patients and are essential to the development of new treatments. These studies also deepen our understanding of diseases, especially rare diseases, such as SCD, where few advances have been made. For rare diseases in particular, only 5 percent of diseases have an FDA-approved treatment[iii], so there is a lot of work to be done in this area.
At their core, clinical trials are designed to produce high-quality data that will translate into a better understanding of the treatments that work best for certain diseases and people. Given their crucial role in medical science, clinical trials are highly regulated and conducted using high-quality scientific and ethical standards to ensure the safety of participating patients.
Are there potential challenges associated with clinical trials?
The biggest challenge is that a clinical trial may fail, even after decades of research aimed at uncovering a treatment breakthrough. While no one likes to hear a clinical trial didn’t meet its goals, especially people in need of new treatment options, researchers are unfortunately unable to anticipate the end results of these studies in advance.
However, even though we can’t be sure of the results, it’s still critical for this research to happen to bring new treatment advances to those in need. Did you know that for every approved medicine, there are countless others that don’t pass through the grueling clinical trial and regulatory processes? A recent report found that the likelihood of drugs moving from clinical phase to approval is only 9.6 percent [iv]. Moreover, even if an investigational therapy is backed by promising data, it can take around 12 years or longer for it to gain approval.
Another challenge can be enrollment of volunteers to participate in clinical trials. Historically, recruitment obstacles have been a barrier in SCD research. However, a poll conducted, as a part of Pfizer and the NNPA’s collaboration, found that a majority of respondents had positive or neutral attitudes toward SCD clinical trials, and furthermore, they indicated a willingness to participate in them if provided the appropriate information. These results are encouraging and suggest people are becoming more inclined to participate in clinical trials for hard-to-treat diseases like SCD.
What have you learned about clinical trials during your time at Pfizer?
Pfizer strives to accelerate the development and delivery of groundbreaking medicines and the dedication, talent and resources that support our clinical trials can’t be captured in a few words. However, as I’ve said earlier, advancing research and conducting clinical trials comes with the unfortunate reality of not always being successful.
The news that our trial for rivipansel didn’t achieve its goals was disappointing, especially for the SCD community who is eagerly awaiting new therapies for VOCs. That said, we are channeling this loss into renewed energy and making it our purpose to learn from it. We are in the process of reviewing the trial data closely to ensure our findings can help inform and shape future SCD programs.
Regardless of the outcomes, I want to stress again that more trials in the rare disease space, particularly for SCD, are desperately needed. I am confident in saying our steadfast commitment to this community will continue, as we work tirelessly to look for new ways to continue advancing care.
About Dr. Kevin Williams
Dr. Kevin Williams is the Chief Medical Officer (CMO) for Pfizer Rare Disease. In this role, he leads a Medical Affairs organization of approximately 150 medical colleagues around the globe supporting Pfizer’s efforts and portfolio in Rare Disease. Dr. Kevin joined Pfizer in January 2004 as a Director of Regional Medical & Research Specialist working in the HIV disease area. After moving into a Team Leader position in July 2005, he served in various leadership roles during his career at Pfizer. Dr. Kevin moved into his current Rare Disease CMO position in May 2016.
Dr. Kevin received his medical degree from the UCLA School of Medicine and is board certified in Internal Medicine. Following a two-year fellowship in Health Services Research at UCLA and a brief academic career as an Instructor of Medicine at the UCLA School of Medicine, he spent eight years in private practice caring for HIV-positive patients while maintaining an academic appointment at the UCLA School of Medicine as an Assistant Clinical Professor of Medicine. In addition to his medical degree, Dr. Kevin has a Master’s in Public Health from the UCLA School of Public Health and a Juris Doctorate from Harvard Law School.
 Serjeant GR. One hundred years of sickle cell disease. Br J Haematol. 2010;151(5):425-429.
 American Family Physician. “Approach to the Vaso-occlusive Crisis in Adults with Sickle Cell Disease.” https://www.aafp.org/afp/2000/0301/p1349.html.
 Global Genes. “Rare Disease: Facts and Statistics.” https://globalgenes.org/rare-diseases-facts-statistics/
 Biotechnology Innovation Organization (BIO). “Clinical Development Success Rates 2006-2015.”