Memorial Sloan Kettering hematologic oncologist Mark Geyer

Mark B. Geyer, MD

Hematologic Oncologist

Clinical Expertise

Adult Acute and Chronic Leukemias; Acute Lymphoblastic Leukemia (ALL); Chronic Lymphocytic Leukemia (CLL); Hairy Cell Leukemia; Lymphoproliferative Disorders; Cellular Immunotherapy

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Accepted Insurance Providers

Dr. Geyer accepts the following list of insurance providers. Select your insurance provider to see more details.

Contact and Location

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Find a Convenient Location

Memorial Sloan Kettering has locations throughout New York City, Long Island, New Jersey, and Westchester. These locations offers many services, including screening, chemotherapy, and medical testing.

About Me


MD, Columbia University College of Physicians and Surgeons


Internal Medicine – Massachusetts General Hospital


Hematology/Medical Oncology – Memorial Sloan Kettering Cancer Center

Board Certifications

Internal Medicine; Hematology; Medical Oncology

I am a hematologist and medical oncologist who specializes in caring for people with leukemia. I am a member of the Leukemia Service and Center for Cell Engineering at Memorial Sloan Kettering. I am committed to providing personalized, compassionate care for our patients and their families.

I often meet patients and their families and caregivers during a very challenging and emotionally charged period in their lives. I value the strong partnerships I form with our patients and their caregivers through both illness and wellness. I want us to make important decisions about care together.

As a researcher, I want to improve the way we treat blood cancers. The past several years have seen exciting developments in therapies for acute lymphoblastic leukemia and chronic lymphocytic leukemia in particular. We have made strides in understanding these conditions. I hope to develop safe and effective therapies and to define how best to use them in caring for people with leukemia.

I have a strong interest in using the power of the immune system to fight blood cancers more effectively. This treatment approach is called immunotherapy. I am working to develop and deliver chimeric antigen receptor T cell therapies for people with leukemia or lymphoma. This field holds great promise, though it has a different set of challenges compared with traditional chemotherapy. Because of the skill and experience of the nurses and doctors at MSK, we are able to deliver the newest treatments in the safest possible manner.

When I meet with patients, my goal is for them to leave the appointment feeling informed and empowered. I want them to know that they are in good hands. I listen carefully to their perspective and address their concerns. I also explain the range of options available to us, outline the advantages and disadvantages of each, and offer my recommendation. I often remind my patients and their families that we never stop caring for them. Our entire team of experts will be there to support and guide them through all of the stages of their journey. 

Awards and Honors

  • American Society of Hematology Scholar Award (2018-2020)
  • Lymphoma Research Foundation Postdoctoral Fellowship Grant (2017-2019)
  • Abstract Achievement Award, American Society of Hematology (2016)
  • Conquer Cancer Foundation Merit Award, American Society of Clinical Oncology (2016)


Doctors at Memorial Sloan Kettering work as teams, with specialists from all different areas. This allows us to consider all your needs together, and to give you the best possible care.

Clinical Trials

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Find a Clinical Trial for You

Memorial Sloan Kettering's doctors and scientists are constantly developing new treatments for cancer. MSK is typically running hundreds of clinical trials at a given time.

You may be able to participate in a clinical trial even if you are new to MSK. Search our online directory to find trial information and see more about who can participate.

Research and Publications

Geyer MB, Rivière I, Sénéchal B, Wang X, Wang Y, Purdon TJ, Hsu M, Devlin SM, Halton E, van Leeuwen DG, Sadelain M, Palomba ML, Park JH, Brentjens RJ. 2019. Safety and tolerability of conditioning chemotherapy followed by CD19-targeted CAR T-cells for relapsed/refractory CLL. JCI Insight. 4(9): e122627.

King AC, Pappacena JJ, Tallman MS, Park JH, Geyer MB. 2019. Blinatumomab Administered Concurrently with Oral Tyrosine Kinase Inhibitor Therapy is a Well-Tolerated Consolidation Strategy and Eradicates Measurable Residual Disease in Adults with Philadelphia Chromosome Positive Acute Lymphoblastic Leukemia. Leukemia Research. 79: 27-33.

Publications on PubMed

Visit PubMed for a full listing of Dr. Geyer’s journal articles. Pubmed is an online index of research papers and other articles from the US National Library of Medicine and the National Institutes of Health.