SWOG’s rare cancers clinical trial has hit the halfway mark for patient enrollment in its initial phase, averaging two new registered patients each day. Called DART, short for Dual Anti-CTLA-4 & Anti-PD-1 blockade in Rare Tumors, the trial is a unique federally funded immunotherapy trial devoted to rare cancers.

The success of DART in attracting patients is notable for several reasons. For people with rare cancers, which together make up about 20 percent of all cancers diagnosed worldwide, DART provides access to the latest drugs – in this case the immunotherapy combination of ipilimumab and nivolumab from Bristol-Myers Squibb. For physicians, the trial offers a treatment option for patients who often have few, if any, choices. For researchers, DART continues to gather patient data, as well as an extensive collection of rare tumor tissue samples, that will seed future scientific and clinical studies.

Finally, with international Rare Disease Day approaching on February 28, DART provides proof that rare cancers can successfully be studied in clinical trials.

“Rare cancers are, by definition, individually scarce and so researchers assume that they will never find enough patients, and find them fast enough, to complete meaningful clinical trials,” said Dr. Sandip Patel, the DART clinical study chair. “And so trials don’t get done. And the perception is reinforced. What we’ve shown at SWOG is that rare cancers not only can be studied, but that these trials can accrue quickly. We have more than 750 hospitals, cancer centers, and clinics across the U.S. that offer DART. We have a goal of enrolling 707 patients over three years, and have enrolled 329 in just over a year. The team is grateful for the enthusiasm for this study, and appreciative of the support of SWOG, the National Cancer Institute, the rare tumor advocacy community and, most importantly, our patients.”

DART is managed by SWOG, the cancer clinical trials group that is part of the National Cancer Institute’s National Clinical Trials Network (NCTN). The NCI sponsors the trial, working under a public-private Cooperative Research and Development Agreement (CRADA) with Bristol-Myers Squibb.

According to the definition used for DART, rare cancers are those diseases with less than a 6 in 100,000 incidence per year. These include dozens of types, including cancers in nerves, glands, bones, and skin.

What makes DART unique is its innovative “basket” design, which allows the testing of a single drug or drug combination in a variety of tumor types. DART currently has 37 cohorts open, each containing patients with a single rare cancer type. Cohorts include rare subtypes of cancers of the ovary, small intestine, lung, sinuses, pancreas, breast, and more that are largely ineligible for other trials. There is also a special cohort for patients who don’t fit in a traditional cohort, but who still get the immunotherapy drugs and submit their tissue samples. Sometimes, enough patients with a certain tumor type are identified in this group to start their own cohort. Either way, most patients with a rare cancer are accepted onto the trial.

A hallmark of DART is its collaborative nature. Dr. Razelle Kurzrock, the DART senior study chair, senior deputy center director at the UC San Diego Moores Cancer Center, and chair of SWOG’s early therapeutics and rare cancers committee, developed the protocol idea with Dr. Patel, an assistant professor of medicine and assistant director of the Clinical Trials Office at Moores Cancer Center, as well as Dr. Young Kwang Chae, an assistant professor in the Division of Hematology/Oncology in the Feinberg School of Medicine at Northwestern University and co-director of the Developmental Therapeutics Program at the Lurie Cancer Center. Dr. Chae is vice chair of SWOG’s early therapeutics and rare cancers committee and DART’s translational medicine study chair. Former Lurie Cancer Center member and SWOG investigator Dr. Frank Giles was also part of the trial development team.

The DART team also includes Dr. Donna Hansel, a pathologist and professor at UC San Diego; Megan Othus, Ph.D., Melissa Plets, M.S., and Edward Mayerson, MS, SWOG biostatisticians at Fred Hutchinson Cancer Research Center; Dr. Christopher Ryan, SWOG executive officer for early therapeutics and rare cancers and professor at the Knight Cancer Institute at Oregon Health & Science University; Dion Holmes, SWOG protocol coordinator; Marcia Horn, SWOG patient advocate and president and CEO of the International Cancer Advocacy Network; and Jeffrey Chuang, Ph.D., and Dr. Karolina Palucka from The Jackson Laboratory, a SWOG science partner. DART partners also include the NCI’s Cancer Therapy Evaluation Program (CTEP) and Bristol-Myers Squibb, which is providing the study drugs.

SWOG is part of the National Cancer Institute’s National Clinical Trials Network and the NCI Community Oncology Research Program, SWOG has nearly 12,000 members in 46 states and six foreign countries who design and conduct cancer clinical trials to improve the lives of people with cancer. Founded in 1956, SWOG’s 1,300 trials have led to the approval of 14 cancer drugs, changed more than 100 standards of cancer care, and saved more than 3 million years of human life. Learn more at swog.org.