Trainees find their chosen specialty through a variety of paths. Hematology and Oncology Fellow Brooke Jennings, MD encountered hers for the first time at the foot of her brother’s hospital bed when she was fifteen years old. In a narrative medicine piece, Jennings describes how coming of age alongside his diagnosis of Ewing sarcoma meant that she “learned medicine backwards.” She internalized the deeply personal implications of cancer pathology long before she formally studied it.
That experience has quietly shaped everything since. Now partway through her first year of fellowship at UI Health Care, Jennings has already authored two clinical trials and is developing a third—a pace that reflects both her clinical ambitions and a purpose that has motivated her since adolescence.
Three trials, one direction
The first trial Jennings authored is currently enrolling patients. The study evaluates patient responses to standard immunotherapies—PD-1 or PD-L1 inhibitors—combined with subcutaneous 5-azacitidine (5-AZA), a nucleoside analog. Although immune-mediated therapies have improved outcomes across several malignancies, many patients remain unresponsive or eventually develop resistance. A common culprit is epigenetic dysregulation: when a tumor fails to display cancerous antigens that allow T-cells to identify and target it, immunotherapy loses its foothold. Research suggests that 5-AZA can restore antigen expression on several tumor types, potentially removing that barrier when combined with PD-1 or PD-L1 inhibitors.
Jennings and her team are exploring a way to restore the immune pathway, leveraging 5-AZA to restore MHC class presentation.
“5-AZA is an injectable chemotherapy,” Jennings said. “We’re exploring how the responses may differ when combining this with immunotherapy across various malignancies that are treated with PD-1/PDL-1 inhibitors that are now refractory to treatment. I am interested in seeing how this could be a new avenue to overcome immunotherapy resistance.”
Her second trial, currently awaiting IRB approval, takes a different approach to a challenge in melanoma care. Although surgery cures most early-stage melanoma, a subset of cases recur and oncologists lack reliable biomarkers to determine which patients are at risk. To address this gap, Jennings designed a window-of-opportunity (WOO) trial that uses the period before surgery to study immune activity in early-stage tumor development. Enrolled patients will receive neoadjuvant injections of RP2, an oncolytic virus, allowing the research team to evaluate immune response and gather translational data in real time.
“This window-of-opportunity trial is a huge opportunity to look at what a drug is doing in humans, at the cellular level, and bring your scientists directly into that work,” Jennings said. “These are our real patients, real comparable samples—and they’re already getting the standard-of-care as we safely study how a new drug could transform the future of care for this population.”
While the second trial awaits approval, Jennings has already begun developing a third. This study will investigate whether bladder matrix (UBM)—an FDA-approved extracellular matrix scaffold with an established clinical safety record in wound healing—can reprogram the tumor microenvironment when paired with standard-of-care PD-1 therapy. In preclinical models of melanoma, UBM has demonstrated promise alongside PD1 by suppressing tumor growth and activating immune cells. The trial targets patients with PD-1/PD-L1-refractory melanoma, a population with limited options and much to gain if novel therapies can activate their tumor’s immune activity.
“My main focus is to be a clinical trialist, but I strongly value my background in basic science research,” Jennings said. “I want to make sure we’re using every opportunity to involve scientists however we can—to answer more questions in our trials. Getting before- and after samples isn’t always possible. But it’s still an opportunity you wouldn’t want to miss. If your science is backing why you think something will work, get the sample, your team of scientists work on it, and see if you can validate what’s going on.”
Returning to where it started
Jennings has known for some time that her “ultimate goal” was to serve patients at home in Iowa, whether in the clinic or through research. After growing up in Winfield, a small town in southeast Iowa, she pursued her undergraduate degree at the University of Iowa, where she joined the Melanoma Lab and began building the research foundation of her career. She stayed at Iowa for medical school at Carver College of Medicine, deepening her ties within the Division of Hematology, Oncology, and Blood & Marrow Transplantation (HOBMT) before residency at Gundersen Health System in La Crosse, Wisconsin.
The time away was clarifying.
“Training at both Iowa and Gundersen gave me valuable perspective on different models of patient care,” Jennings said. “I’m incredibly grateful for the experience and mentorship I received at Gundersen. That time helped clarify that I want to build a career as a clinical trialist working closely with basic science collaborators, in melanoma and sarcoma. Being at an academic center makes that possible, because it allows clinical care, translational research, and subspecialty expertise to be closely integrated. That perspective ultimately led me back to Iowa.”
The thread connecting each of her steps, she said, had more to do with people than institutions. As a first-generation college student, Jennings worked deliberately to build mentorship connections. She committed herself to meeting professionals within her areas of interest, naming her goals out loud, and following her curiosity. Initially, she felt drawn to the idea of becoming a cancer biologist, an independent investigator who could prioritize research. Then, between volunteering in a research lab during her undergraduate studies, Jennings developed a love for patient interactions at her part-time CNA job. She asked Mohammed Milhem, MBBS, clinical professor in HOBMT, if she could shadow him in the clinic. After observing how patient care and science could be integrated, Jennings said that “the rest was history.”
She also credits her earliest supporters: “My brother’s diagnosis was very formative in high school, but so was my interest in science, which many of my teachers encouraged me to explore more,” Jennings said. “I couldn’t have done what I do without their support, and I’m still in touch with many of them today.”
The bigger picture
Jennings returns to scale repeatedly when describing why clinical research draws her in.
“I just want to provide good care to my patients. I want them to know that someone is behind them,” she said. “But I think the bigger picture is that clinical trials give you the opportunity to impact thousands of people across the United States—people who you may never meet, but whose lives can change if your trial changes practice. Then, your work is going a lot farther than just you.”
That sense of reach extends in both directions. In a second narrative piece she wrote for a competition hosted by the Journal of Clinical Oncology Narrative Medicine titled “I Will Carry You With Me,” Jennings reflects on patients who have stayed with her.
One patient, whom she refers to as “Mr. B,” arrived at an appointment during a period of remission wearing Green Bay Packers gear from head to toe, insisting that she cheer for his team that weekend. After his melanoma returned and he passed away, Jennings still checks the score when the Packer’s play. When they win, she thinks of Mr. B’s smile.
Another patient—a young mother, “Mrs. S”—carried a buckeye in her pocket at every appointment as a token of strength and good luck. Before Mrs. S died, she gave one to Jennings. That buckeye sits on her desk, always within reach.
“Would I have ever known the story of the buckeye or the recent score of the Packers game without crossing paths with Mr. B and Mrs. S? Likely not.” Jennings writes. “That’s the gift of this work: we carry their stories—their voices, their habits, their symbols of hope. They shape who we are.”