Criteria for clinical trials might be too strict, needlessly excluding patients

Health news

DALLAS – December.
17th, 2019 – Federal regulations may keep lung cancer patients
out of clinical trials simply because these patients are on medications that
might affect the electrical system of the heart. Drilling into the details
quickly turns up reasons to think these regulations may be preventing a
substantial proportion of patients from participating in clinical trials. There
may be alternatives, and researchers and physicians should explore them.

These are
the conclusions of a team of researchers from UT Southwestern Medical Center
that included members of the Harold C. Simmons Comprehensive Cancer Center.

Their
findings, published in the journal Clinical Lung Cancer in November,
might help break down barriers for patients to participate in important,
potentially lifesaving clinical trials. The barriers currently exclude
thousands of patients.

“This issue
comes up all the time in my practice,” said Dr. David Gerber, who treats lung
cancer patients and is a Professor of Internal Medicine and Population and Data
Sciences. He is one of the study’s authors and has been studying clinical trial
eligibility criteria for a decade.

Clinical
trial eligibility criteria are designed to limit risks to study participants.
But, according to Dr. Gerber, these criteria may be excessive in places.

“The
criteria are not as thoughtful as they could be,” Dr. Gerber said. “We keep
cutting and pasting from earlier studies, basically doing the same things over
and over without justifying them or deciding if they’re rational.”

Using a
database of more than 280,000 Veterans Health Administration patients with lung
cancer, the study found that more than 25 percent of lung cancer patients were
prescribed medications with potential cardiac risk, and almost 10 percent were
taking multiple such medications. Dr. Gerber noted that even if these
medications are not having cardiac effects on patients, simply receiving the
medications may bar patients from clinical trials. Furthermore, when cardiac
effects are noted, the actual risk to patients is often measured over a 40-year
period. Because most lung cancer patients are over 70 years old, a 40-year
range of possible risks may be less relevant.

“Lung cancer
is a serious and possibly life-threatening condition,” Dr. Gerber said. “When
we design clinical trials, we need to consider potential benefits as well as
theoretical risks.”

Dr. Carlos
L. Arteaga, Director of the Simmons Cancer Center and Associate Dean of
Oncology Programs, said studies like Dr. Gerber’s are urgently needed because
less than 2 percent of adult cancer patients in the U.S. are enrolled in
clinical trials that can benefit the patient and advance scientific knowledge.
He said clinical trials for lung cancer are particularly important because lung
cancer is the leading cause of cancer deaths in Texas and the nation.

“Studying
barriers to clinical trials can be as important as creating a new clinical
trial itself. Patients can’t benefit from trials they can’t access,” said Dr.
Arteaga, also Professor of Internal Medicine who holds The Lisa K. Simmons
Distinguished Chair in Comprehensive Oncology. “Dr. Gerber’s work is one of the
first steps in making clinical trials more accessible.”

Dr. Mark
Link, a cardiologist and Professor of Internal Medicine who worked on the
study, said the seemingly excessive caution around the drugs stems largely from
a medical crisis in the late 1990s. A new drug created to treat gastric
motility disorders such as diarrhea, vomiting, and severe constipation showed
positive effects on the gastrointestinal tract but serious threats to the
heart.

“This new
drug was widely used and very effective. It worked extremely well, but then the
reports started coming in of QTc prolongation of this drug, and it was taken
off the market,” said Dr. Link, who holds the Laurence and Susan Hirsch/Centex
Distinguished Chair in Heart Disease.

QTc
prolongation
is the
blip on an electrocardiogram, the iconic machine on the medical TV shows
that charts each heartbeat with a beep and a fever chart line. The space
between the highest peaks on the EKG line is known as the QTc interval. It is
the moment the heart is preparing to beat again. It’s a crucial step in cardiac
health – in staying alive – so the threats caused by the gastric motility
disorder drug prompted the FDA to zero in on other drugs that affect QTc
prolongation. The fallout included strict rules stating that patients taking
drugs that prolong – or even might prolong – QTc intervals cannot enter
clinical cancer trials.

The most
common QTc-prolonging medications that the study found to be potential barriers
to clinical trials included antibiotics, psychiatric medications, and cardiac
medications.

Other researchers who contributed to the study were Dr. Tri Le, a hematology-oncology postdoctoral fellow; Dr. Sawsan Rashdan, Assistant Professor of Internal Medicine; Dr. Carlos Alvarez, Associate Professor of Population and Data Sciences; and Dr. Hui Yang, a Chief Analyst at Texas Tech University Health Science Center.

About UT
Southwestern Medical Center

UT
Southwestern, one of the premier academic medical centers in the USA,
integrates pioneering biomedical research with exceptional clinical care and
education. The institution’s faculty has received six Nobel Prizes, and
includes 22 members of the National Academy of Sciences, 17 members of the
National Academy of Medicine, and 15 Howard Hughes Medical Institute
Investigators.

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