Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Clinical efficacy of a RAF inhibitor needs broad target blockade in BRAF-mutant melanoma

Abstract

B-RAF is the most frequently mutated protein kinase in human cancers1. The finding that oncogenic mutations in BRAF are common in melanoma2, followed by the demonstration that these tumours are dependent on the RAF/MEK/ERK pathway3, offered hope that inhibition of B-RAF kinase activity could benefit melanoma patients. Herein, we describe the structure-guided discovery of PLX4032 (RG7204), a potent inhibitor of oncogenic B-RAF kinase activity. Preclinical experiments demonstrated that PLX4032 selectively blocked the RAF/MEK/ERK pathway in BRAF mutant cells and caused regression of BRAF mutant xenografts4. Toxicology studies confirmed a wide safety margin consistent with the high degree of selectivity, enabling Phase 1 clinical trials using a crystalline formulation of PLX4032 (ref. 5). In a subset of melanoma patients, pathway inhibition was monitored in paired biopsy specimens collected before treatment initiation and following two weeks of treatment. This analysis revealed substantial inhibition of ERK phosphorylation, yet clinical evaluation did not show tumour regressions. At higher drug exposures afforded by a new amorphous drug formulation4,5, greater than 80% inhibition of ERK phosphorylation in the tumours of patients correlated with clinical response. Indeed, the Phase 1 clinical data revealed a remarkably high 81% response rate in metastatic melanoma patients treated at an oral dose of 960 mg twice daily5. These data demonstrate that BRAF-mutant melanomas are highly dependent on B-RAF kinase activity.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Three-dimensional structure of PLX4032 binding to B-RAF(V600E).
Figure 2: Effect of PLX4032 on COLO205 xenograft tumour growth.
Figure 3: Semi-quantitative immunohistochemistry (IHC) in paired tumour biopsies.
Figure 4: Representative PET scans for patients taken pre-dose and following 2 weeks of dosing with PLX4032.

Similar content being viewed by others

Accession codes

Primary accessions

Protein Data Bank

Data deposits

Atomic and structural data have been deposited in Protein Data Bank under accession number 3OG7.

References

  1. Greenman, C. et al. Patterns of somatic mutation in human cancer genomes. Nature 446, 153–158 (2007)

    Article  ADS  CAS  Google Scholar 

  2. Davies, H. et al. Mutations of the BRAF gene in human cancer. Nature 417, 949–954 (2002)

    Article  ADS  CAS  Google Scholar 

  3. Solit, D. B. et al. BRAF mutation predicts sensitivity to MEK inhibition. Nature 439, 358–362 (2006)

    Article  ADS  CAS  Google Scholar 

  4. Yang, H. et al. RG7204 (PLX4032), a selective BRAFV600E inhibitor, displays potent antitumor activity in preclinical melanoma models. Cancer Res. 70, 5518–5527 (2010)

    Article  CAS  Google Scholar 

  5. Flaherty, K. et al. Inhibition of mutated, activated BRAF in metastatic melanoma. N. Engl. J. Med. 363, 809–819 (2010)

    Article  CAS  Google Scholar 

  6. Tsai, J. et al. Discovery of a selective inhibitor of oncogenic B-Raf kinase with potent antimelanoma activity. Proc. Natl Acad. Sci. USA 105, 3041–3046 (2008)

    Article  ADS  CAS  Google Scholar 

  7. Hatzivassiliou, G. et al. RAF inhibitors prime wild-type RAF to activate the MAPK pathway and enhance growth. Nature 464, 431–435 (2010)

    Article  ADS  CAS  Google Scholar 

  8. Koch, W. H. Technology platforms for pharmacogenomic diagnostic assays. Nature Rev. Drug Discov. 3, 749–761 (2004)

    Article  ADS  CAS  Google Scholar 

  9. Rubinstein, J. C. et al. Incidence of the V600K mutation among melanoma patients with BRAF mutations, and potential therapeutic response to the specific BRAF inhibitor PLX4032. J. Transl. Med. 8, 67 (2010)

    Article  Google Scholar 

  10. Esteve-Puig, R., Canals, F., Colome, N., Merlino, G. & Recio, J. A. Uncoupling of the LKB1-AMPKα energy sensor pathway by growth factors and oncogenic BRAFV600E . PLoS ONE 4, e4771 (2009)

    Article  ADS  Google Scholar 

  11. Zheng, B. et al. Oncogenic B-RAF negatively regulates the tumor suppressor LKB1 to promote melanoma cell proliferation. Mol. Cell 33, 237–247 (2009)

    Article  CAS  Google Scholar 

  12. Søndergaard, J. N. et al. Differential sensitivity of melanoma cell lines with BRAFV600E mutation to the specific B-Raf inhibitor PLX4032. J. Transl. Med. 8, 39 (2010)

    Article  Google Scholar 

  13. Arnault, J. P. et al. Keratoacanthomas and squamous cell carcinomas in patients receiving sorafenib. J. Clin. Oncol. 27, e59–e61 (2009)

    Article  Google Scholar 

  14. Dubauskas, Z. et al. Cutaneous squamous cell carcinoma and inflammation of actinic keratoses associated with sorafenib. Clin. Genitourin. Cancer 7, 20–23 (2009)

    Article  CAS  Google Scholar 

  15. Kong, H. H. et al. Keratoacanthomas associated with sorafenib therapy. J. Am. Acad. Dermatol. 56, 171–172 (2007)

    Article  Google Scholar 

  16. Schwartz, G. K. et al. A phase I study of XL281, a selective oral RAF kinase inhibitor, in patients (Pts) with advanced solid tumors. J. Clin. Oncol. 27, 3513 (suppl.), (2009)

    Article  Google Scholar 

  17. Kefford, R. et al. Phase I/II study of GSK2118436, a selective inhibitor of oncogenic mutant BRAF kinase, in patients with metastatic melanoma and other solid tumors. J. Clin. Oncol. 28, 8503 (suppl.), (2010)

    Article  Google Scholar 

  18. Heidorn, S. J. et al. Kinase-dead BRAF and oncogenic RAS cooperate to drive tumor progression through CRAF. Cell 140, 209–221 (2010)

    Article  CAS  Google Scholar 

  19. Poulikakos, P. I., Zhang, C., Bollag, G., Shokat, K. M. & Rosen, N. RAF inhibitors transactivate RAF dimers and ERK signalling in cells with wild-type BRAF. Nature 464, 427–430 (2010)

    Article  ADS  CAS  Google Scholar 

  20. Courtois-Cox, S. et al. A negative feedback signaling network underlies oncogene-induced senescence. Cancer Cell 10, 459–472 (2006)

    Article  CAS  Google Scholar 

  21. Dougherty, M. K. et al. Regulation of Raf-1 by direct feedback phosphorylation. Mol. Cell 17, 215–224 (2005)

    Article  CAS  Google Scholar 

  22. Hall-Jackson, C. A. et al. Paradoxical activation of Raf by a novel Raf inhibitor. Chem. Biol. 6, 559–568 (1999)

    Article  CAS  Google Scholar 

  23. Rajakulendran, T., Sahmi, M., Lefrancois, M., Sicheri, F. & Therrien, M. A dimerization-dependent mechanism drives RAF catalytic activation. Nature 461, 542–545 (2009)

    Article  ADS  CAS  Google Scholar 

  24. Pratilas, C. A. et al. V600EBRAF is associated with disabled feedback inhibition of RAF-MEK signaling and elevated transcriptional output of the pathway. Proc. Natl Acad. Sci. USA 106, 4519–4524 (2009)

    Article  ADS  CAS  Google Scholar 

  25. Kolch, W. Coordinating ERK/MAPK signalling through scaffolds and inhibitors. Nature Rev. Mol. Cell Biol. 6, 827–837 (2005)

    Article  CAS  Google Scholar 

  26. Pollock, P. M. et al. High frequency of BRAF mutations in nevi. Nature Genet. 33, 19–20 (2003)

    Article  CAS  Google Scholar 

  27. Michaloglou, C. et al. BRAFE600-associated senescence-like cell cycle arrest of human naevi. Nature 436, 720–724 (2005)

    Article  ADS  CAS  Google Scholar 

  28. Korn, E. L. et al. Meta-analysis of phase II cooperative group trials in metastatic stage IV melanoma to determine progression-free and overall survival benchmarks for future phase II trials. J. Clin. Oncol. 26, 527–534 (2008)

    Article  Google Scholar 

Download references

Acknowledgements

We thank L. Andries and M. Knaapen from HistoGeneX for evaluating paired biopsies, and also our colleagues at the Molecular Imaging Research division of Charles River Labs for conducting the xenograft studies. We also thank D. Heimbrook, S. Cheng, L. Burdette and B. Lestini for helpful comments on the manuscript. This research was funded in part by NIH grants to K.L.N.

Author information

Authors and Affiliations

Authors

Contributions

G.B., P.H., C.Z., K.L.N. and K.N. designed studies, interpreted data and wrote the manuscript. J.T., G.H., E.A.B., B.W., G.T., B.L.W., B.P., R.S., A.M., H.N., F.S., and B.H. conducted or managed biochemical or biological studies. J.Z., P.N.I., H.C., W.S., D.R.A. and R.I. designed and conducted chemistry and formulation experiments. Y.Z. and K.Y.J.Z. conducted and interpreted structural studies. J.S. helped interpret data and write the manuscript. K.D., A.K., M.S. and X.X. designed, managed and interpreted biomarker studies. P.S.L., R.J.L., J.G., I.P., K.B.K., A.R., G.A.M., J.A.S., P.B.C. and K.T.F. managed or conducted clinical and translational studies.

Corresponding author

Correspondence to Gideon Bollag.

Ethics declarations

Competing interests

[Many of the authors are employed by the biotechnology company Plexxikon or the pharmaceutical company Roche, as indicated in the author affiliations.]

Supplementary information

Supplementary Information

This file contains Supplementary Methods, Supplementary Results, additional references and Supplementary Tables 1-3. (PDF 182 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bollag, G., Hirth, P., Tsai, J. et al. Clinical efficacy of a RAF inhibitor needs broad target blockade in BRAF-mutant melanoma. Nature 467, 596–599 (2010). https://doi.org/10.1038/nature09454

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature09454

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing