How Many LQTS Patients are There?
We are now Thryv.
LQT Therapeutics Inc. has changed its name to Thryv Therapeutics Inc.
Over the past few months we’ve made great progress at LQT Therapeutics. Our research is beginning to pay off as several of our compounds have demonstrated promising initial effects in inducible pluripotent stem cells from patients with Long QT Syndrome (LQTS) - a standard cellular experiment used to evaluate the potential of therapies to manifest changes in action potential duration - a electrical signal correlated to the QT interval.
We have multiple compounds that have the basic characteristics of a potential clinical lead compound and we continue to advance towards initial toxicology studies which will enable our eventual clinical programs. It seems, in light of our promising (still early) research results, that we should revisit our Long QT Syndrome patient populations and put this rare disease into perspective.
One of the primary challenges of rare diseases is that they are … well, rare. A disease is generally defined as rare if it affects less than 200,000 U.S. adults. While rare diseases are individually uncommon, there are many rare diseases in the aggregate, with nearly 7,000 rare diseases affecting 25-30 million U.S. adults, or roughly 9-12 percent of the U.S. population.
Patients with rare diseases face three primary challenges:
They suffer the consequences of the disease but continue to live undiagnosed,
They experience the manifestations of the disease, but struggle to find physicians knowledgeable enough about their condition to effectively treat and manage them,
They may face high costs for disease-specific medications and treatments.
For physicians dealing with patients diagnosed with rare diseases, knowledge with managing such diseases are typically concentrated in a relatively few number of highly experienced clinics where clinicians have taken special interest and have developed deep experience with these conditions. Of course, a clinician’s expertise in managing any disease or disorder is proportional to the frequency with which she treats patients with the disease or disorder.
At LQT Therapeutics, we’re often asked, “How prevalent is Long QT Syndrome?” and “How many patients are treated annually?” They are great questions and while we can attempt to estimate the number of patients from genetic studies or extrapolate from hospital admissions, often we don’t precisely know how many people are afflicted, until a therapy is available …
The prevalence of Long QT Syndrome
There’s a lot unknown about the population of Long QT Syndrome (LQTS) patients, but there are several known ones. First, LQTS affects males and females in equal numbers and appears equally prevalent in all ethnic groups. The responsible mutation is genetically transmitted and thus it tends to run in families.
We also know animal models are difficult for researchers to exploit as they tend to be unreliable, unrepresentative of the true disease, and/or unproven. Recent advances in the use of stem cells from LQTS patients is by far the best tool researchers have.
LQTS is a disease that does not discriminate, and it is a very human disease, often resulting in sudden cardiac death.
The exact incidence and prevalence of the LQTS is not known. A 2009 study of nearly 45,000 infants found 17 cases of Long QT Syndrome, or 1 in 2,500 newborns. Sixteen of those cases were confirmed through genetic screening. While the study had some limitations, when combined with the findings of Dr. Silvia Priori’s study where more than 35 percent of patients with Long QT Syndrome experienced serious cardiac events by the time they are 40, the need for new approaches becomes very clear.
Citation: Prevalence of the Congenital Long-QT Syndrome, Peter J. Schwarz, et. al., Oct. 19, 2009
Citation: Kaplan–Meier Estimates of Cumulative Survival Free of Cardiac Events among the 580 Patients with the Long-QT Syndrome in the Risk-Stratification Analysis, According to the Quartile of the QT Interval Corrected for Heart Rate (QTc).
LQTS is a human condition with a very real human impact, and at a rate of 1 in 2,500 newborns, prevalence could well be north of 130,000 people in the United States alone. Most importantly, we have the ability, and perhaps even a moral obligation, to diagnose LQTS and uncover the patients born with this disease. While ECG screening is often utilized for competitive school sports, multiple organizations including the Cardiac Safety Research Consortium and the FDA (though other stakeholders are expected to become engaged) are exploring approaches to childhood screening in the US.
Prevalence vs. importance
Prevalence aside, LQTS is an important disease for several reasons. LQTS is often a lethal disorder, and symptomatic patients left without therapeutic treatment have a very high mortality rate within one year from a patient’s first syncope (temporary loss of consciousness caused by a fall in blood pressure). They also experience clinically meaningful symptoms such as marked lightheadedness and syncope. Current therapies, mainly beta blockers and implantable defibrillators, are not adequate, and thus there remains a major unmet medical need for new therapies.
Even with less than optimal treatments and their inherent life-altering side effects (often leading to non-compliance), the impact on mortality alone makes the search for treatments of symptomatic but undiagnosed patients mission-critical.
Additionally, LQTS is a cardiac disease in which molecular biology and genetics have made tremendous progress and is a prime example of the genotype-phenotype correlation. In this regard it represents a paradigm for sudden cardiac death, and further progressive study in both the lab and the clinic helps the entire medical community to better understand the mechanisms underlying sudden death in more complex cardiac disorders such as ischemic heart disease and heart failure.
Answering a question with a question?
How prevalent is LQTS? How many patients are there? How many would be “enough?”
LQT Therapeutics has been honored to share the LQTS stories of the most courageous people we’ve ever met:
Charlie Moisey, a young mother and a 4x cardiac arrest survivor
Alexis Holmgren, a young Canadian who doesn’t let LQTS slow her down from a number of accomplishments, working tirelessly for inclusion for everyone
Daiana Diaz Montes, a beacon of joy for her central California community
Darcy Carhill, who went from flatlining to giving birth … over the span of just nine minutes
Emily Boone, who doesn’t let LQTS slow her down from working as a full-time occupational therapist
Marjaan Barbano, a cardiac arrest survivor who has recently started a family
Sarah Michaelis-Heidman, a 25-year old 3x cardiac arrest survivor committed to driving awareness for a number of life-altering conditions
Isla Hutton, a four-year old Brit who will melt your heart with her smile
Alexander, Adrien and Palmire Thomas, all reaching, and one dancing, for the stars despite LQTS
These brave LQTS warriors are part of the community that inspires our team at LQT Therapeutics, and stokes the fire that drives us to #BeRelentless in finding advanced treatments - and eventually a cure. Read their stories and join us in spreading the word about LQTS.
Long QT Syndrome is a discoverable disease that can be treated, and we’re working tirelessly in the laboratory to uncover even more effective treatments - for these strong and courageous people.
