Research Summary

The over-arching goal of my research career has been to develop and expand curative therapies for hemoglobin disorders in particular and non-malignant hematopoietic disorders more broadly. I have focused on genome editing approaches most recently, which rely upon modification of autologous hematopoietic cells to elicit a curative effect. In collaboration with colleagues at UC Berkeley, BCHO and UCLA, we are pursuing genomic editing of the sickle mutation in hematopoietic stem cells using the CRSPR/Cas9 ribonucleoprotein system. I have a long track record of experience in cellular therapies for pediatric acquired and hereditary conditions and in bone marrow transplantation.

Research Funding

  • April 25, 2020 - March 31, 2022 - Addressing safety issues by quantify large deletions and chromosomal rearrangements in HBB gene editing , Co-Investigator . Sponsor: NIH, Sponsor Award ID: OT2HL154977
  • September 1, 2015 - July 31, 2021 - Hematopoietic Stem Cell Transplantation for Young Adults with Sickle Cell Disease - Clinical Coordinating Center , Co-Principal Investigator . Sponsor: NIH, Sponsor Award ID: U01HL128566
  • September 20, 2019 - June 30, 2021 - Clinical Microfluidic Assessment of Red Blood Cell Adhesion, Deformability, Cellular Hemoglobin Distribution, Cellular Density, and Blood Rheology for Curative Therapies in Sickle Cell Disease , Co-Investigator . Sponsor: NIH, Sponsor Award ID: OT2HL152643
  • June 12, 2019 - May 31, 2021 - Curing Sickle Cell Disease with CRISPR-Cas9 genome editing , Principal Investigator . Sponsor: NIH, Sponsor Award ID: OT2HL151319
  • September 1, 2011 - April 30, 2016 - Hematopoietic Cell Therapy for Young Adults with Severe Sickle Cell Disease , Co-Principal Investigator . Sponsor: NIH, Sponsor Award ID: R34HL108761
  • April 18, 2006 - March 31, 2011 - Northern California Consortium for Sickle Cell Disease , Principal Investigator . Sponsor: NIH, Sponsor Award ID: U10HL083704
  • August 25, 2001 - July 31, 2007 - Induction of Stable Chimerism for Sickle Cell Anemia , Principal Investigator . Sponsor: NIH, Sponsor Award ID: U01HL068091
  • July 10, 1998 - June 30, 2002 - MECHANISMS OF GLOBIN GENE SILENCING , Principal Investigator . Sponsor: NIH, Sponsor Award ID: R29HL060927
  • August 1, 1992 - June 30, 2001 - GLOBIN GENE REGULATION BY GATA-1 AND CHROMATIN , Co-Principal Investigator . Sponsor: NIH, Sponsor Award ID: R01HL048790
  • July 1, 1994 - June 30, 1999 - MECHANISMS OF ERYTHROID GENE EXPRESSION , Principal Investigator . Sponsor: NIH, Sponsor Award ID: K08HL003098

Education

2019 - Diversity, Equity, and Inclusion Champion Training, University of California
06/1991 - Pediatric Hem/Onc/BMT fellowship, Fred Hutch/Univ of Washington
06/1988 - Pediatric Residency, University of Washington
M.D., 06/1985 - Medicine, University of California, San Diego
A.B., 06/1981 - Genetics, University of California, Berkeley

Selected Publications

  1. Walters MC, Eapen M, Liu Y, El Rassi F, Waller EK, Levine JE, Strouse JJ, Antin JH, Parikh SH, Bakshi N, Dampier C, Jaroscak JJ, Bergmann S, Wong T, Kota V, Pace B, Lekakis LJ, Lulla P, Nickel RS, Kasow KA, Popat U, Smith W, Yu L, DiFronzo N, Geller N, Kamani N, Klings ES, Hassell K, Mendizabal A, Sullivan K, Neuberg D, Krishnamurti L. Hematopoietic cell transplant compared with standard care in adolescents and young adults with sickle cell disease. Blood Adv. 2025 Mar 11; 9(5):955-965.  View on PubMed
  2. Kassim AA, Walters MC, Eapen M, Smith M, Logan BR, Solh M, McKinney C, Nieder M, Ross M, Kent M, Abusin GA, Mallhi K, Silva JG, Shaughnessy P, Kanter J, Haines H, Farah R, Khaled YA, Ritzau N, Mendizabal A, Abraham A, Bollard C, Cooke K, de la Fuente J, Hanna R, Horowitz MM, Jordan LC, Bakshi N, Krishnamurti L, Leifer E, Mahadeo KM, Shenoy S, Jones RJ, DeBaun MR, Brodsky RA. Haploidentical Bone Marrow Transplantation for Sickle Cell Disease. NEJM Evid. 2025 Mar; 4(3):EVIDoa2400192.  View on PubMed
  3. John TD, Walters MC, Rangarajan HG, Rahim MQ, McKinney C, Bollard CM, Abusin G, Eapen M, Kassim AA, DeBaun MR. Incremental eligibility criteria for the BMT CTN 1507 haploidentical trial for children with sickle cell disease. Blood Adv. 2024 Dec 10; 8(23):6055-6063.  View on PubMed
  4. Kwiatkowski JL, Walters MC, Hongeng S, Yannaki E, Kulozik AE, Kunz JB, Sauer MG, Thrasher AJ, Thuret I, Lal A, Tao G, Ali S, Thakar HL, Elliot H, Lodaya A, Lee J, Colvin RA, Locatelli F, Thompson AA. Betibeglogene autotemcel gene therapy in patients with transfusion-dependent, severe genotype β-thalassaemia (HGB-212): a non-randomised, multicentre, single-arm, open-label, single-dose, phase 3 trial. Lancet. 2024 11 30; 404(10468):2175-2186.  View on PubMed
  5. Lessard S, Rimmelé P, Ling H, Moran K, Vieira B, Lin YD, Rajani GM, Hong V, Reik A, Boismenu R, Hsu B, Chen M, Cockroft BM, Uchida N, Tisdale J, Alavi A, Krishnamurti L, Abedi M, Galeon I, Reiner D, Wang L, Ramezi A, Rendo P, Walters MC, Levasseur D, Peters R, Harris T, Hicks A. Zinc finger nuclease-mediated gene editing in hematopoietic stem cells results in reactivation of fetal hemoglobin in sickle cell disease. Sci Rep. 2024 10 16; 14(1):24298.  View on PubMed
  6. Walters M. A Cure for Sickle Cell Disease. Transplant Cell Ther. 2024 Jul; 30(7):637-640.  View on PubMed
  7. Braniecki S, Vichinsky E, Walters MC, Shenoy S, Shi Q, Moore TB, Talano JA, Parsons SK, Flower A, Panarella A, Fabricatore S, Morris E, Mahanti H, Milner J, McKinstry RC, Duncan CN, van de Ven C, Cairo MS. Neurocognitive outcome in children with sickle cell disease after myeloimmunoablative conditioning and haploidentical hematopoietic stem cell transplantation: a non-randomized clinical trial. Front Neurol. 2024; 15:1263373.  View on PubMed
  8. Frangoul H, Locatelli F, Sharma A, Bhatia M, Mapara M, Molinari L, Wall D, Liem RI, Telfer P, Shah AJ, Cavazzana M, Corbacioglu S, Rondelli D, Meisel R, Dedeken L, Lobitz S, de Montalembert M, Steinberg MH, Walters MC, Eckrich MJ, Imren S, Bower L, Simard C, Zhou W, Xuan F, Morrow PK, Hobbs WE, Grupp SA, CLIMB SCD-121 Study Group. Exagamglogene Autotemcel for Severe Sickle Cell Disease. N Engl J Med. 2024 05 09; 390(18):1649-1662.  View on PubMed
  9. Eapen M, Kou J, Andreansky M, Bhatia M, Brochstein J, Chaudhury S, Haight AE, Haines H, Jacobsohn D, Jaroscak J, Kasow KA, Krishnamurti L, Levine JE, Leung K, Margolis D, Yu LC, Horowitz MM, Kamani N, Walters MC, Shenoy S. Long-term outcomes after unrelated donor transplantation for severe sickle cell disease on the BMT CTN 0601 trial. Am J Hematol. 2024 04; 99(4):785-788.  View on PubMed
  10. Corbacioglu S, Frangoul H, Locatelli F, Hobbs W, Walters M. Defining curative endpoints for transfusion-dependent β-thalassemia in the era of gene therapy and gene editing. Am J Hematol. 2024 03; 99(3):422-429.  View on PubMed
  11. Locatelli F, Corbacioglu S, Hobbs W, Frangoul H, Walters MC. Defining curative endpoints for sickle cell disease in the era of gene therapy and gene editing. Am J Hematol. 2024 03; 99(3):430-438.  View on PubMed
  12. Olson TS, Walters MC. Allogeneic haematopoietic stem-cell transplantation versus gene therapy for haemoglobinopathies. Lancet Haematol. 2023 10; 10(10):e798-e800.  View on PubMed
  13. Hall AG, Winestone LE, Sullivan EM, Wu Q, Lamble AJ, Walters MC, Aguayo-Hiraldo P, Baez Conde L, Coker TR, Dornsife D, Keating AK, Merino DM, Ramsey B, Park JR, Agrawal AK. Access to Chimeric Antigen Receptor T Cell Clinical Trials in Underrepresented Populations: A Multicenter Cohort Study of Pediatric and Young Adult Acute Lymphobastic Leukemia Patients. Transplant Cell Ther. 2023 06; 29(6):356.e1-356.e7.  View on PubMed
  14. Lin C, Schwarzbach A, Sanz J, Montesinos P, Stiff P, Parikh S, Brunstein C, Cutler C, Lindemans CA, Hanna R, Koh LP, Jagasia MH, Valcarcel D, Maziarz RT, Keating AK, Hwang WYK, Rezvani AR, Karras NA, Fernandes JF, Rocha V, Badell I, Ram R, Schiller GJ, Volodin L, Walters MC, Hamerschlak N, Cilloni D, Frankfurt O, McGuirk JP, Kurtzberg J, Sanz G, Simantov R, Horwitz ME. Multicenter Long-Term Follow-Up of Allogeneic Hematopoietic Cell Transplantation with Omidubicel: A Pooled Analysis of Five Prospective Clinical Trials. Transplant Cell Ther. 2023 May; 29(5):338.e1-338.e6.  View on PubMed
  15. Eapen M, Brazauskas R, Williams DA, Walters MC, St Martin A, Jacobs BL, Antin JH, Bona K, Chaudhury S, Coleman-Cowger VH, DiFronzo NL, Esrick EB, Field JJ, Fitzhugh CD, Kanter J, Kapoor N, Kohn DB, Krishnamurti L, London WB, Pulsipher MA, Talib S, Thompson AA, Waller EK, Wun T, Horowitz MM. Secondary Neoplasms After Hematopoietic Cell Transplant for Sickle Cell Disease. J Clin Oncol. 2023 04 20; 41(12):2227-2237.  View on PubMed
  16. Lawal RA, Walters MC, Fitzhugh CD. Allogeneic Transplant and Gene Therapy: Evolving Toward a Cure. Hematol Oncol Clin North Am. 2022 12; 36(6):1313-1335.  View on PubMed
  17. Krishnamurti L, Neuberg D, Sullivan KM, Smith S, Eapen M, Walters MC. Enrollment Lessons from a Biological Assignment Study of Marrow Transplantation versus Standard Care for Adolescents and Young Adults with Sickle Cell Disease: Considerations for Future Gene and Cellular Therapy Trials. Transplant Cell Ther. 2023 04; 29(4):217-221.  View on PubMed
  18. Kanter J, Thompson AA, Pierciey FJ, Hsieh M, Uchida N, Leboulch P, Schmidt M, Bonner M, Guo R, Miller A, Ribeil JA, Davidson D, Asmal M, Walters MC, Tisdale JF. Lovo-cel gene therapy for sickle cell disease: Treatment process evolution and outcomes in the initial groups of the HGB-206 study. Am J Hematol. 2023 01; 98(1):11-22.  View on PubMed
  19. Magis W, DeWitt MA, Wyman SK, Vu JT, Heo SJ, Shao SJ, Hennig F, Romero ZG, Campo-Fernandez B, Said S, McNeill MS, Rettig GR, Sun Y, Wang Y, Behlke MA, Kohn DB, Boffelli D, Walters MC, Corn JE, Martin DIK. High-level correction of the sickle mutation is amplified in vivo during erythroid differentiation. iScience. 2022 Jun 17; 25(6):104374.  View on PubMed
  20. Kanter J, Walters MC, Krishnamurti L, Mapara MY, Kwiatkowski JL, Rifkin-Zenenberg S, Aygun B, Kasow KA, Pierciey FJ, Bonner M, Miller A, Zhang X, Lynch J, Kim D, Ribeil JA, Asmal M, Goyal S, Thompson AA, Tisdale JF. Biologic and Clinical Efficacy of LentiGlobin for Sickle Cell Disease. N Engl J Med. 2022 02 17; 386(7):617-628.  View on PubMed

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