Hematology/Oncology, UCLA School of Medicine, 2001
Surgical Oncology, UCLA School of Medicine, 1998
Hospital Vall d'Hebron, 1994
Medical Oncology, Hospital Vall d'Hebron, 1991
MD, Universidad de Barcelona, 1990



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  • About Me

    About Me

    Antoni Ribas, MD, PhD is a Professor of Medicine, Professor of Surgery, and Professor of Molecular and Medical Pharmacology at the University of California Los Angeles (UCLA). He is the Director of the Tumor Immunology Program at the Jonsson Comprehensive Cancer Center (JCCC), Vice-President of the Society for Melanoma Research (SMR) and the Chair of the Melanoma Committee at SWOG. He trained at the University of Barcelona, Spain, with postdoctoral research and clinical fellowship at UCLA.

    Dr. Ribas is a permanent committee member of the National Cancer Institute (NCI) grant review panels and an elected member of the American Society of Clinical Investigation (ASCI). He has published over 200 manuscripts on laboratory and clinical research in malignant melanoma.

    * Photo credit © Ann Johansson


  • Locations

    UCLA Medical Center Hematology/Oncology

    (primary location)
    100 UCLA Medical Plaza
    Suite 550
    Los Angeles, California 90095
  • Education


    Hematology/Oncology, UCLA School of Medicine, 2001
    Surgical Oncology, UCLA School of Medicine, 1998
    Hospital Vall d'Hebron, 1994
    Medical Oncology, Hospital Vall d'Hebron, 1991
    MD, Universidad de Barcelona, 1990
  • Clinical Interests
    • Melanoma
    • Phase 1 Clinical Trials
  • Research

    Research Interest

    As a physician-scientist, Dr. Ribas has a NIH and California State-funded laboratory where he conducts research focusing on adoptive cell transfer with T cell receptor (TCR) engineered lymphocytes, anti-CTLA4 antibodies, anti-PD-1 antibodies, BRAF-targeted therapies and nanoparticle-siRNA therapeutics.


    Selected publications:
    1. M.E. Davis, J.E. Zuckerman, C.J. Choi, D. Seligson, A. Tolcher, C.A. Alabi, Y. Yen, J.D. Heidel, A. Ribas. Evidence of RNAi in humans from systemically administered siRNA via targeted nanoparticles. Nature 2010 Apr 15; 464 (7291): 1067-70. PMC2855406.
    2. K.T. Flaherty, I. Puzanov, K.B. Kim, A. Ribas, G.A. McArthur, J.A. Sosman, P.J. O’Dwyer, R.J. Lee, J. Grippo, K. Nolop, P.B. Chapman. Selective inhibition of BRAF-V600E activating mutations induce major regressions in patients with metastatic melanoma. New England Journal of Medicine 2010, 363 (9): 809-19. PMCID pending.
    3. G. Bollag, P. Hirth, J. Tsai, J. Zhang, P.N. Ibrahim, H. Cho, W. Spevak, C. Zhang, G. Habets, B. Burton, B.L. West, B. Powell, R. Shellooe, A. Marimuthu, H. Nguyen, K.Y.J. Zhang, D.R. Artis, J. Schlessinger, F. Su, B. Higgins, R. Iyer, A. Koehler, R.J. Lee, J. Grippo, I. Puzanov, K.B. Kim, A. Ribas, G.A. McArthur, J.A. Sosman, P.B. Chapman, K.T. Flaherty, K. D’Andrea, X. Xu, K.L. Nathanson, K. Nolop. Clinical efficacy of a B-RAF inhibitor requires substantial ERK pathway inhibition in BRAF-mutant melanoma. Nature Sep 30; 2010 467 (7315): 596-9. PMC2948082.
    4. R. Nazarian, H. Shi, Q. Wang, X. Kong, R.C. Koya, H. Lee, Z. Chen, M.-K. Lee, N. Attar, H. Sazegar, T. Chodon, S.F. Nelson, G.A. McArthur, J.A. Sosman, A. Ribas, R.S. Lo. Melanomas acquire resistance to V600EB-RAF inhibition by RTK upregulation or N-RAS mutation. Nature 2010 Dec 16; 468 (7326): 973-7. PMCID pending.
    5. R.C. Koya, S. Mok, B. Comin-Anduix, T. Chodon, M.I. Nishimura, C.G. Radu, O.N. Witte, A. Ribas. Kinetic Phases of Distribution and Tumor Targeting by Adoptively Transferred T Cell Receptor Engineered Lymphocytes Inducing Robust Antitumor Responses. Proceedings of the National Academy of Sciences (PNAS) 2010 Aug 10; 107 (32): 14286-91.
    6. P.B. Chapman, A. Hauschild, C. Robert, J.B. Haanen, P. Ascierto, J. Larkin, R. Dummer, C. Garbe, A. Testori, M. Maio, D. Hogg, P. Lorigan, C. Lebbe, T. Jouary, D. Schadendorf, A. Ribas, S.J. O'Day, J.A. Sosman, J.M. Kirkwood, A.M.M. Eggermont, B. Dreno, K. Nolop, J. Li, B. Nelson, J. Hou, R.J. Lee, K.T. Flaherty, G.A. McArthur, for the BRIM-3 Study Group. Improved Survival with Vemurafenib in Patients with BRAFV600E Mutant Metastatic Melanoma. New England Journal of Medicine 2011 Jun 30; 364 (26): 2507-16. PMCID pending.
    7. P.I. Poulikakos, Y. Persaud, M. Janakiraman, X. Kong, C. Ng, G, Moriceau, H. Shi, M, Atefi. B, Titz, M.T. Gabay, M. Salton, K.B. Dahlman, Tadi Madhavi, J.A. Wargo, K.T. Flaherty, M.C. Kelley, T. Misteli, J.A. Sosman, P.B. Chapman, T.G. Graeber, A. Ribas, R.S. Lo, N. Rosen, D.B. Solit. Acquired resistance to RAF inhibitors is mediated by splicing isoforms of BRAF(V600E) that dimerize in a RAS independent manner. Nature 2011 480 (7377): 387-90. PMCID: PMC3266695.
    8. C. Ma, R. Fan, H. Ahmad, Q. Shi, B. Comin-Anduix, T. Chodon, R.C. Koya, C.-C. Liu, G.A. Kwong, C.G. Radu, A. Ribas, J.R. Heath. A Microchip Platform for Single Cell, Multiplexed Evaluation of Immune Cell Function Applicable to the Immune Monitoring of Immunotherapy Clinical Trials. Nature Medicine 2011 Jun; 17 (6): 738-43. PMCID pending.
    9. F. Su, A. Viros, C. Milagre, K. Trunzer, G. Bollag, O. Spleiss, J. S. Reis-Filho, X. Kong, R.C. Koya, M.J. Kim, R. Hayward, M. Martin, H. Yang, Q. Wang, J. Noe, M. Lambros, F. Geyer, N. Dhomen, I. Niculescu-Duvaz, A. Zambon, D. Niculescu-Duvaz, N. Preece, L. Robert, N.J. Otte, S. Mok, D. Kee, Y. Ma, C. Zhang G. Habets, E.A. Burton, B. Wong, H. Nguyen, J.L. Troy, K.T. Flaherty, P.B. Chapman, R. Gonzalez, T.E. Hutson, I. Puzanov, B. Lestini, K.B. Nolop, R.J. Lee, A.K. Joe, C.J. Springer, J.A. Sosman, G.A. McArthur, R.S. Lo, A. Ribas*, R. Marais*. RAS mutations in cutaneous squamous cell carcinomas with BRAF inhibitors. *equal contribution as senior authors. New England Journal of Medicine 2012; 366: 207-15. PMCID pending.
    10. J.A. Sosman, K.B. Kim, L. Schuchter, R. Gonzalez, A.C. Pavlick, J.S. Weber, G.A. McArthur, T.E. Hutson, S.J. Moschos, D. Lawrence, P. Hersey, R. Kefford, K.T. Flaherty, I. Puzanov, K.D. Lewis, R.K. Amaravadi, B. Chmielowski, H.J. Lawrence, Y. Shyr, F. Ye, J. Li, K.B. Nolop, R.J. Lee, A.K. Joe, A. Ribas. Long-Term Survival in Vemurafenib Treated BRAFV600-Metastatic Melanoma. New England Journal of Medicine 2012 Feb 23; 366 (8): 707-14. PMCID pending.
    11. R.C. Koya, S. Mok, N. Otte, K.J. Blacketor, B. Comin-Anduix, P.C. Tumeh, A. Minasyan, N.A. Graham, T.G. Graeber, T. Chodon, A. Ribas. BRAF inhibitor vemurafenib improves the antitumor activity of adoptive cell immunotherapy. Cancer Research 2012 Aug 15; 72 (16): 3928-37.
    12. R. Straussman, T. Morikawa, K. Shee, M. Barzily-Rokni, Z.R. Qian, J. Du, A. Davis, M.M. Mongare, J. Gould, D.T. Frederick, Z.A. Cooper, P.B. Chapman, D.B. Solit, A. Ribas, R.S. Lo, K.T. Flaherty, S. Ogino, J.A. Wargo, T.R. Golub. Tumor microenvironment contributes to RAF-inhibitor resistance through HGF secretion. Nature 2012 Jul 26; 487 (7408): 500-4.
    13. C. Ma, A.F Cheung, T. Chodon, R.C Koya, Z. Wu, C. Ng, O.N. Witte, D. Baltimore, B. Chmielowski, J.S. Economou, B. Comin-Anduix, A. Ribas*, J.R. Heath*. Polyfunctionality analysis of TCR transgenic lymphocytes used for adoptive cell transfer therapy uncovered changes correlated with clinical antitumor activity. *equal contribution as corresponding authors. Cancer Discovery 2013 3 (4): 418-29.
    14. O. Hamid, C. Robert, A. Daud, F.S. Hodi, W-J. Hwu, R. Kefford, J.D. Wolchok, P. Hersey, R.W. Joseph, J.S. Weber, R. Dronca, T.C. Gangadhar, A. Patnaik, H. Zarour, A.M. Joshua, K. Gergich, J. Elassaiss-Schaap, A. Algazi, C. Mateus, P. Boasberg, P.C. Tumeh, B. Chmielowski, S.W. Ebbinghaus, X. Li, S.P. Kang, A. Ribas. Safety and Tumor Responses with Lambrolizumab (Anti PD-1) in Melanoma. New England Journal of Medicine 2013 Jul 11; 369 (2): 134-44. PMCID pending.
    15. S. Mok, R.C. Koya, C. Tsui, J. Xu, L. Wu, T.G. Graeber, B.L. West, G. Bollag, A. Ribas. Inhibition of Colony Stimulating Factor 1 Receptor (CSF-1R) Improves Anti-tumor Activity of Adoptive Cell Transfer Immunotherapy. Cancer Research January 1, 2014, 74 (153-161.
  • News & Awards


    • 2013 Outstanding Research Award, Society for Melanoma Research (SMR).
    • 2013 Physician of the Year, Melanoma International Foundation.
    • 2009 Elected member of the American Society of Clinical Investigation (ASCI).
    • 2008 New Faculty Award from the California Institute of Regenerative Medicine (CIRM).
    • 2005 Melanoma Research Foundation Junior Researcher Award.
    • 2002 Stop Cancer Career Development Award.
    • 2002 K23 CA93376 Career Development Award.
    • 2000 Clinical Research Career Development Award from the American Society of Clinical Oncology (ASCO).
    • 2000 Amgen Oncology Fellow Award. 2000 Fellow Teaching Award, UCLA.
    • 1997 Extraordinary Prize and Suma Cum Laude, Doctoral Thesis. Autonomous University of Barcelona.