Leading the next era of bone marrow transplantation 

Specialists at Penn Medicine Hematology Oncology have been performing potentially lifesaving allogeneic stem cell transplants for more than three decades. The program’s history of autologous stem cell transplants extends back even further. Over those years, the blood and marrow transplant program has grown to one of the largest in the nation, completing a total of 2,250 allogeneic transplants and 5,570 autologous transplants as of late 2025.

Today, the program performs transplants nearly every day, more than any other health system in the Philadelphia region. “As a longstanding transplant program with a rich history, we have expertise in standard-of-care bone marrow transplants as well as customized treatments and novel therapies being offered through clinical trials,” says Alison Wakoff Loren, MD, MSCE, Chief of the Division of Hematology Oncology and Director of Blood and Marrow Transplantation at Penn Medicine. “We’ve been doing this a long time, and that experience translates to excellent patient care.”

New advances in bone marrow transplant

Hematopoietic stem cell transplants are high-risk procedures, but they hold the promise of great reward. They are the only form of curative treatment for people with myelodysplastic syndrome and most people with acute myeloid leukemia (AML). They also have lifesaving potential for treating acute lymphoblastic leukemia (ALL) and a variety of other blood cancers.

A standard of care for decades, bone marrow transplant continues to evolve rapidly. Penn Medicine’s blood and marrow transplantation program plays a leading role in many recent innovations.

Expanding options for older adults

Traditionally, high doses of chemotherapy were given to prepare patients for transplant. However, such dosing regimens were generally too risky for patients over the age of 65. In the United States, the average age of diagnosis for all blood cancers is 68, meaning this potentially curative treatment was unavailable to the population that needed it most.

To close that treatment gap, Penn Medicine helped pioneer reduced-intensity transplants using lower doses of chemotherapy, making transplants more accessible to older adults and patients with comorbidities who might not otherwise be healthy enough to receive a transplant. Today, Penn Medicine’s team includes several physicians with specialized expertise in bone marrow transplants for older patients.

Clinical trials

Penn Medicine is a Core Clinical Center of the Blood & Marrow Clinical Trials Network, a multi-institution effort funded by the National Heart, Lung, and Blood Institute and the National Cancer Institute to improve outcomes in bone marrow transplant and other cellular therapies. Since its inception in 2001, the network has launched more than 65 clinical studies, providing opportunities to more than 17,300 patients.

Recent trials at Penn Medicine include research to expand bone marrow transplantation in patients with severe aplastic anemia, efforts to “pre-rehabilitate” (or pre-hab) frail patients to prepare them for transplant, and new approaches to manage graft-versus-host disease. “There is so much innovation happening to make our cellular therapy treatments better,” Dr. Loren says.

Gene therapy

Penn Medicine has begun administering new gene therapy treatments for inherited blood disorders such as thalassemia. In these groundbreaking new therapies, patients’ stem cells are collected, modified to correct or overcome faulty genes, then reinfused into patients.

Women’s health

Bone marrow transplants often lead to sexual and reproductive side effects in women, including infertility and early menopause. Penn Medicine transplant and oncology physicians have partnered with our experts in reproductive endocrinology as well as women’s health to develop expedited referrals for fertility preservation, as well as a new menopause survivorship program to support women and improve their sexual health.

Specialized expertise in stem cell transplants

The hematologic malignancy team at Penn Medicine includes physicians specializing in each blood cancer subtype. It also features a team of experts with more than 200 years of combined experience who focus exclusively on bone marrow transplant. That team meets weekly to discuss care plans for each patient and share changing treatment standards, new research findings, and emerging clinical trial opportunities. “When you see one of us, you’re really seeing all of us,” Dr. Loren says.

That team-based approach carries through the entire transplant journey, and beyond the core transplant team. “Bone marrow transplant patients can require a lot of specialized care,” Dr. Loren says.

Patients undergoing transplant sometimes require intensive care. They can develop rare infections or have specialized transfusion needs. “We have a whole team ready to care for transplant patients, including transplant experts and all of the supporting specialists who understand how to treat these patients in the context of a bone marrow transplant,” she adds.

Referring patients to Penn Medicine

For many patients with hematologic malignancies, stem cell transplants can provide the best—and sometimes the only—chance at a cure. But transplants are an art as well as a science, Dr. Loren says. It can take two months or more to plan the procedure, test potential donors, and prepare patients for transplant. “Because of the importance of planning and timing, a delay in transplant referral can make a big difference in whether a patient can ultimately receive this curative treatment,” she says.

In the past, some patients may have been considered poor candidates for bone marrow transplant due to their age or the severity of their illness. As transplant techniques and supportive care have advanced, more patients are benefiting from these treatments. Yet even those who may not ultimately receive a transplant can benefit from a referral, since patients are also evaluated for other advanced therapies. This includes investigational treatments such as novel cellular therapies like CAR T cell therapy.

Those novel treatments are evolving quickly. The Penn Medicine Translational Center of Excellence in Genetically Engineered Hematopoietic Stem Cell Transplantation, for example, was created to catalyze translational research in gene-engineered hematopoietic stem cell therapy and drive first-in-human testing through clinical trials.

The Penn Medicine team works closely with referring providers to ensure patients get timely, compassionate care as close to home as possible. “We care deeply about each patient and their unique circumstances and work hard to provide care that aligns with their values and treatment goals,” Dr. Loren says.

Clinical consult and patient referral

To refer a patient to the Penn Medicine Division of Hematology and Oncology, call 877-937-7366 or refer a patient online.