Clinical trials are the key to unlocking innovation in cancer drug development but hurdles throughout the process are keeping patients from signing up for studies.

Just 7.1% of US adults with cancer participated in cancer treatment trials during 2013-2017, according to a recent analysis published in the Journal of Clinical Oncology. Of those participants, 21.6% enrolled in trials at National Cancer Institute-Designated Cancer Centers, while only 4.1% participated in trials run at community sites.

“We don’t have enough people who are participating in clinical trials and those who are participating aren’t necessarily representative of our diverse population,” said Leah Szumita, senior director of the Clinical Trial Support Center at Blood Cancer United, formerly The Leukemia & Lymphoma Society. “We want everyone to have access to the best care possible, but we also need to ensure that these treatments will work for everyone.”

Coverage and Out-of-Pocket Costs

One of the biggest barriers to enrollment is the cost for patients to participate in cancer treatment trials.

“There’s this myth that [trials are] free and they’re not,” Szumita said.

Trial sponsors are typically responsible for providing the experimental drug or treatment at no cost to patients. However, the routine care that surrounds it, from diagnostic imaging and lab tests to physician office visits and inpatient hospital services, is supposed to be covered by a patient’s health insurance.

“If they don’t have insurance, they have to have an enormous amount of money to be able to pay for those healthcare costs,” Szumita said.

Even for patients who do have insurance, defining what is routine care can be murky, with some insurers refusing to cover imaging or lab tests that are part of the trial’s monitoring protocol if they exceed the standard of care. If a patient would typically get two scans over the course of a month and they are now getting 10 as part of the trial, it’s not always clear who is paying for that, said Bethany Lilly, executive director of public policy at Blood Cancer United.

“You really have to understand the in-depth details of their insurance to understand what would be covered and what wouldn’t be covered,” Lilly said. “That’s the challenge that many, many patients run into. They know they have health insurance, but they might not know the exact parameters of it.”

Patients are also likely to take on added out-of-pocket costs if they have to go out-of-network for a clinical trial. Insurers with a closed network of providers do not have to cover out-of-network trial care. Even patients with some out-of-network coverage as part of their health plans face higher copayments and deductibles if their trial doctors are out of network.

Location Matters

Location is also a big factor in whether patients can participate in a clinical trial, said Shanti Sivendran, MD, a hematologist-oncologist and senior vice president for cancer treatment support at the American Cancer Society (ACS). She practices in Pennsylvania and most major clinical trials are located 90 minutes to 2 hours from her location.

Even though the trial may offer lifesaving cancer treatment, patients tend to not want to participate in trials that will take them away from their families multiple times a week, Sivendran said. There’s also the added expense of transportation, parking, and even lodging, she said.

Lilly recalled a patient who rented a motor home and parked it outside the trial location because that was easier and safer than flying to the site and staying in a hotel during treatment.

Groups like the ACS can offer some financial assistance for travel and lodging and some state Medicaid programs provide reimbursement for travel, but the assistance is a patchwork.

Szumita said how the financial assistance is given is also an important consideration. When patients have to submit reimbursement for their expenses, it assumes that they can afford to pay upfront. Better options include a concierge service that makes arrangements on behalf of patients or a prepaid debit card, she said.

Trial Eligibility

Trial eligibility itself can be a barrier to broader patient participation in trials. In an analysis of disability exclusion in clinical trials, researchers found that just 18% of trials explicitly allowed people with disabilities to use forms of support to aide in trial participation and 85% of protocol gave investigators broad discretion to determine eligibility.

The analysis, which included 97 phase 3 clinical trials involving adult patients with dementia, depression, diabetes, and lung cancer, also found that less than one quarter of the studies had documented the justification for the exclusion of patients with disabilities.

Barbara E. Bierer, MD, a hematologist-oncologist and faculty director of the Multi-Regional Clinical Trials (MRCT) Center of Brigham and Women’s Hospital and Harvard, who was an author on the analysis, said there are two ways that disability can keep patients from enrolling in a clinical trial. One is that trials are not created in a universally accessible way, so they are operationally very difficult for people with disabilities. The other is the exclusion — whether intentional or unintentional — of people with disabilities based on strict eligibility criteria or simply a lack of specificity in the eligibility criteria.

Willyanne DeCormier Plosky, DrPH, program director at the MRCT Center who was also an author on the analysis, said that many cancer studies use the ECOG Performance Status Scale as one of the eligibility criteria. Because many trials have a threshold of ECOG score of ≤ 2, which requires patients to be ambulatory, this can exclude patients in a wheelchair even if it is unrelated to the cancer, she said.

If trials are going to exclude someone with a disability they need to clearly spell out the exclusion and provide a justification that’s based on a scientific or safety reason, DeCormier Plosky said. Reasonable accommodations, such as making the text size bigger for patients with visual impairments, are also necessary.

“People often think that it’s a high cost and it’s a lot of effort, and oftentimes it’s very little effort and no or little cost,” she said.

Matching Programs

Matching programs that help connect patients with cancer with clinical trials are one way that patient advocacy groups are seeking to improve trial participation.

The ACS Access to Clinical Trials and Support program is an end-to-end clinical trial matching service that helps to educate patients about their options and connects them with a clinical trial that meets their needs. The program began as a pilot in February 2025 in the Northeast region of the US. In November 2025, they expanded the program nationally.

Through the program, cancer information specialists perform a health-related social needs screening to identify potential barriers to trial enrollment. For patients who want to take the next step and learn about the clinical trials options, ACS works with the biotech company Massive Bio, which uses artificial intelligence to find the closest possible clinical trials matches between open trials and the patient’s medical record.

Blood Cancer United developed their Clinical Trial Support Center in 2016 as they started to get an increasing number of calls asking about clinical trials. The team began with one part-time nurse and has grown to include 13 staff members. “Clinical trials are no easier to enroll in today than they were back in 2016,” Szumita said.

As part of the free service, the Center matches individuals with blood cancers with a designated nurse navigator who seeks to match them with the best options, whether that is a clinical trial or standard of care.

In 2024, the Center had succeeded at enrolling about 20% of the patients with cancer who had contacted them in at least one clinical trial. But it took an average of 32 interactions on behalf of each patient to get to trial enrollment, from phone calls and emails to learn about insurance coverage to finding travel resources or inquiring about eligibility criteria.

“Those are 32 cracks in a road that a patient potentially would fall through if they tried to do this on their own,” Szumita said.

Other Solutions

Moving trials into the community, where about 80% of patients with cancer receive their care, would be an important step to overcoming geographic barriers, Sivendran said.

Sivendran said her practice runs community-based clinical trials but that it took several years to build the infrastructure and to get buy-in from different levels of leadership.

Indeed, a Medscape survey of oncologists found that while 2 in 3 oncology practices report some involvement in clinical trials, a lack of infrastructure was the top reason that oncology practices opted against clinical trials. Among practices not participating in trials, 62% cited infrastructure as a barrier, followed by the time required (38%).

Even moving some elements of a trial into the community would be helpful, Szumita said. If patients could get blood work done at a local facility or be able to do some physician visits virtually, that could ease some of the travel burdens, she said.

Insurance changes are also needed, Lilly said. For instance, routine care provided in trials should be exempt from cost sharing, and health plans should be required to cover clinical trial care provided by out-of-network doctors and facilities. More also needs to be done to streamline the prior authorization process that can slow down enrollment in a clinical trial, she said.

While there are numerous hurdles to getting patients enrolled in a clinical trial, it all starts with a conversation with the oncologist, Sivendran said. “It’s so important for us to bring it up to our patients regardless of whether the process is hard,” she said.

Bierer, DeCormier Plosky, Lilly, Sivendran, and Szumita reported having no financial disclosures.