Invest New Drugs DOI 10.1007/s10637-014-0191-5

PHASE I STUDIES

Phase I study of XL281 (BMS-908662), a potent oral RAF kinase inhibitor, in patients with advanced solid tumors Mark A. Dickson & Michael S. Gordon & Gerald Edelman & Johanna C. Bendell & Ragini R. Kudchadkar & Patricia M. LoRusso & Stuart H. Johnston & Douglas O. Clary & Gary K. Schwartz

Received: 21 October 2014 / Accepted: 14 November 2014 # Springer Science+Business Media New York 2014

Summary Background XL281 is a potent and selective inhibitor of wild-type and mutant RAF kinases with anti-tumor activity in multiple xenograft models. Mutations in KRAS or BRAF can activate the RAF/MEK/ERK pathway in human tumors and may confer sensitivity to RAF kinase inhibitors. Methods We performed a phase I study of XL281 in patients with advanced solid tumors. Patients were enrolled in successive cohorts of XL281 orally once daily in 28-day cycles. Twice daily dosing, different formulations, and the effect of food and famotidine were also studied. At the MTD expanded cohorts with defined mutations were treated. Results In total, 160 patients were treated. The MTD on the QD schedule was

150 mg. The most common toxicities were diarrhea, nausea, and fatigue. Plasma Cmax and AUC increased with dose. Famotidine resulted in lower AUC while food had no effect. Two patients had partial responses by RECIST: One with papillary thyroid cancer with NRAS mutation and one with uveal melanoma. Another nine patients had tumor decrease of >10 % but did not meet RECIST criteria for PR. Matched tumors pairs from 33 patients showed evidence of RAF inhibition with significant decreases in pERK, pMEK and pAKT. Conclusions XL281 was generally well tolerated and the MTD was established at 150 mg/day. Partial responses and clinical benefit were observed in several patients. Tumor biopsies demonstrated effective target inhibition.

M. A. Dickson (*) Memorial Sloan Kettering Cancer Center, New York, NY, USA e-mail: [email protected]

Keywords Phase I Trials . Kinase inhibitors . Pharmacokinetics and pharmacodynamics

M. A. Dickson Weill Cornell Medical College, New York, NY, USA

Introduction M. S. Gordon Pinnacle Oncology Hematology, Scottsdale, AZ, USA G. Edelman Mary Crowley Cancer Research Center, Dallas, TX, USA J. C. Bendell Sarah Cannon Research Institute, Nashville, TN, USA R. R. Kudchadkar Emory University, Atlanta, GA, USA P. M. LoRusso Yale University, New Haven, CT, USA S. H. Johnston : D. O. Clary Exelixis Inc., South San Francisco, CA, USA G. K. Schwartz Columbia University Medical Center, New York, NY, USA

The RAF family (A-RAF, B-RAF, and C-RAF) of serine/threonine kinases functions as downstream effectors of the membrane-bound G-protein RAS in the mitogen-activated protein kinase/extracellular-signal-related kinase (MAPK/ERK) pathway. Upregulation of this pathway contributes to many hallmarks of malignant cells including proliferation, invasion, metastasis, angiogenesis, and evasion of apoptosis [1, 2].The RAS/ RAF/MEK1/ERK1/2 pathway is up-regulated in approximately 30 % of human cancers, and activating RAS mutations have been reported in 15–30 % of all cancers [3]. In addition to RAS, it has been shown that B-RAF is mutated in approximately 7 % of human cancers, including 40–60 % of malignant melanoma [4, 5] and 35–70 % of papillary thyroid cancer (PTC) [6, 7].

Invest New Drugs

XL281 is a potent orally bioavailable selective inhibitor of wild type and mutant RAF kinases. In vitro, XL281 inhibits CRAF, B-RAF, and B-RAFV600E with concentration required for 50 % inhibition (IC50) values of 2.6, 4.5, and 6 nM, respectively. XL281 showed only weak activity when tested against over 100 other serine/threonine or tyrosine kinases. XL281 shows anti-tumor activity in multiple xenograft models and is associated with decreased tumor cell proliferation and vascularization [8].We performed a phase I study of XL281 in patients with advanced solid tumors.

Study design Objectives The primary objectives of this study were to evaluate the safety and tolerability of once daily (QD) and twice daily (Q12H) oral administration of XL281 in patients with solid tumors and to determine the maximum tolerated dose. Additional objectives were to determine the bioavailability of XL281 under fed and fasted conditions, and with and without concomitant use of a single 40-mg famotidine dose. The secondary and exploratory objectives were to assess the pharmacokinetics (PK) of XL281 and the pharmacodynamic effects of XL281 on tumor samples. Methodology QD dose escalation This study was a nonrandomized open-label evaluation of safety and PK of XL281 in patients with solid tumors. XL281 as a drug-in-capsule (DIC) formulation was administered QD to an initial cohort of three patients at a starting dose of 10 mg. A conventional 3 + 3 dose-escalation design was used to determine the maximum tolerated dose (MTD). Dose escalation proceeded as determined by the Cohort Review Committee on the basis of interim safety and PK data. Once the QD MTD was determined, additional cohorts received XL281 either in an expansion phase at the QD MTD, in a food effect/drug interaction cohort, or in a second Q12H Dose Escalation Phase as follows: QD MTD (expansion) The study was expanded at the recommended phase two dose to treat up to 75 patients with colorectal cancer (CRC), melanoma, non-small cell lung cancer (NSCLC), or papillary thyroid cancer (PTC), including a certain number of CRC and

melanoma patients with tumor mutations in defined RAF pathway-related genes. QD MTD (food effect/drug interaction) Patients were enrolled in a Food Effect/Famotidine Cohort to determine the bioavailability of XL281 under fed versus fasted conditions (with or without the use of a single dose of 40 mg famotidine) at the MTD of 150 mg QD (DIC formulation). Patients were required to fast for at least 10 h prior to their Cycle one Day eight dose (fasted). Patients were also required to fast for at least 8 h prior to receiving one dose of famotidine 2 h prior to their Cycle one Day 15 dose of XL281 (famotidine). Patients were required to fast for at least 10 h prior to their Cycle one Day 22 high fat meal, and then received XL281 30 min after ingesting that meal (fed). Pharmacokinetic blood samples were collected for up to 24 h following the Day 8, Day 15, and Day 22 doses to evaluate the effect of famotidine and the effect of food on the PK profile of XL281. Separately, an additional dose escalation was begun with Q12H dosing as follows: Q12H (escalation) Patients were enrolled in a Q12H Dose Escalation Cohort, in which they received XL281 at an initial dose of 50 mg Q12H (DIC formulation). Dose escalation was stopped at 100 mg Q12H without determining an MTD, and Q12H dose escalation was restarted at 25 mg with a new formulated capsule (FC) formulation that had potential to provide higher systemic exposures compared to the original DIC formulation. Q12H MTD (expansion Arm 3) No patients were enrolled into the Q12H MTD expansion cohort as the study was terminated at 75 mg Q12H of the FC formulation before an MTD could be determined for this regimen. Patient selection Eligibility included age of 18 years or older, histologically confirmed solid tumor that was metastatic or unresectable. In the expansion phase, certain patients with CRC had a tumor specimen that demonstrated mutation of either KRAS or BRAF and certain patients with melanoma had a tumor specimen that demonstrated mutation of one of the following genes: NRAS, HRAS, KRAS, BRAF, GNAQ, or KIT. The protocol was approved by the Institutional Review Board of each participating institution and all patients provided written informed consent (Clinicaltrials.gov identifier NCT00451880).

Invest New Drugs

Treatment plan XL281 was administered orally daily for 28 days (one cycle). In the absence of progressive disease (PD) or unacceptable XL281-related toxicity, patients continued on treatment. After the MTD was determined, patients who were in cohorts receiving a lower dose level than the MTD could receive the study drug at the MTD. Study assessments Safety evaluations included physical examinations, skin examinations, ophthalmic examinations (visual acuity, ophthalmic exams), laboratory assessments (hematology, serum chemistry panel, urinalysis), and electrocardiogram (ECG). Severity of adverse events (AE) was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) v3.0. Tumor response for patients with measurable disease was measured by computerized tomography (CT) or magnetic resonance imaging (MRI) and assessed per Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 every 8 weeks. Pharmacokinetic sample collection Multiple blood samples were collected at Days one and 22, and for the food effects/ Famotidine cohort, detailed PK sampling on Days eight, 15 and 22. On detailed PK sampling days, six or more PK samples were scheduled over a 24-h period. Plasma was isolated from whole blood and analyzed for XL281 using a validated liquid chromatography coupled to tandem mass spectrometry method with a lower limit of quantitation of 0.5 ng/mL.

For each tumor marker, individual subject data were plotted as the ratio of treatment to baseline. These ratios were summarized as the geometric mean and associated 95 % confidence limits. The geometric mean ratio was tested for a significant difference from 1.0 using a two-sided student’s t-test. Baseline and on-treatment tumor samples were evaluated for changes in the levels and phosphorylation of multiple signaling molecules related to the mechanism of action of XL281. The majority of the sample sets were evaluated for phosphorylated ERK (pERK), phosphorylated MEK (pMEK), Ki67, and TUNEL. A subset of the samples was also evaluated for phosphorylated AKT (pAKT [epitope pT308]), total ERK (tERK), and total MEK levels (tMEK). While most analyses were performed using rhodamine fluorescence on sequential slides from a sample, in certain samples, tERK was measured using an alternate channel (fluorescein) from that used for pERK (rhodamine). In this situation, tERK and pERK were assessed on the same sections.

Pharmacokinetic analysis Noncompartmental PK analysis of plasma concentrations was performed using WinNonlin Professional (v. 5.2). Data processing and plotting was done using S-Plus 8.0 for Windows (Enterprise Developer).

Table 1

Patient characteristics

Characteristic

No. patients

Total Male Female Age, median (range) ECOG, 0 1 2 Tumor type CRC Melanoma Thyroid NSCLC Uveal melanoma Other (including pancreas, breast, esophagus, ovarian, sarcoma, carcinoid, renal, small bowel, head and neck, sweat gland, and unknown primary)

160 82 (51 %) 78 (49 %) 61 (27–90)

Tumor tissue pharmacodynamics analysis methods In the expansion phase, selected patients underwent a tumor biopsy prior to treatment with XL281, and again on approximately Day 22, and frozen directly into Optimal Cutting Temperature (OCT) solution. Frozen tissue samples were sectioned at 10 μm, immunostained, and analyzed using fluorescence-based morphometry. Following staining, all sections were assessed for tissue and staining quality, tumor content and localization. Up to 40 non-overlapping representative fields were captured using a Zeiss AxioImager microscope and Axiovision software (Zeiss, Oberkochen, Germany), followed by quantification using the MetaMorph software (Molecular Devices, Sunnyvale, CA). The normalized intensity score was calculated according to the equation below, where Red Pixel indicates the biomarker stained, and Blue Pixel indicates DNA stain (DAPI). Σ IntensityRed Pixel
ðAreaRed Pixel =AreaBlue Pixel Þ

73 (46 %) 81 (51 %) 6 (4 %) 47 (29 %) 40 (25 %) 23 (14 %) 21 (13 %) 6 (4 %) 23 (14 %)

Invest New Drugs Table 2 Incidence of Grade 2–4 adverse events that occurred in at least 5 % of patients, or in at least one patient with Grade 4 severity

Adverse event

G2

(%)

G3

Anemia Abdominal pain Constipation Diarrhea Nausea

10 8 19 17 35

6.3 5 11.9 10.6 21.9

13 10 4 5 7

Vomiting Asthenia Fatigue Pain Urinary tract infection Decreased appetite Dehydration Hyperglycemia Hyponatremia Arthralgia Back pain Pain in extremity Headache Dyspnea

31 6 38 9 14 14 24 4 0 8 7 7 12 15

19.4 3.8 23.8 5.6 8.8 8.8 15 2.5 0 5 4.4 4.4 7.5 9.4

9 3 23 5 1 1 4 3 8 2 3 2 0 2

Results Between April 2007 and September 2011, 160 patients were enrolled in the study. The characteristics of the patient population are showed in Table 1. The median age was 61 (range 27–90) and 51 % of patients were male. Most patients had Eastern Cooperative Oncology Group (ECOG) performance status score of 0–1. The most common cancer diagnoses were colorectal (29 %), melanoma (25 %), thyroid (14 %) and NSCLC (13 %). The MTD on the QD schedule was 150 mg. The maximum administered dose was 225 mg, which was associated with dose-limiting toxicity of pain and fatigue in one patient and vomiting and diarrhea in another. The rates of adverse events in all patients are summarized in Table 2. The most common toxicities were diarrhea, nausea, and fatigue. The mean time on treatment was 92.8 days (range 1–1316+ days). Most patients received either 1 (35.6 %) or two cycles (33.1 %) of treatment. There were 31 patients (19.4 %) who received ≥5 cycles of treatment. The mean number of cycles dosed was 3.5. Approximately 13 % of patients (21/160) had one or more dose reductions during their treatment due to AEs. Approximately 51 % of patients (82/160) experienced a dose delay during treatment, mostly due to AEs. Based on regularly scheduled skin examinations, six squamous cell carcinomas were identified in five patients. Three

(%)

G4

(%)

Total

(%)

8.1 6.3 2.5 3.1 4.4

2 0 0 0 2

1.3 0 0 0 1.3

25 18 23 22 44

15.6 11.3 14.4 13.8 27.5

5.6 1.9 14.4 3.1 0.6 0.6 2.5 1.9 5 1.3 1.9 1.3 0 1.3

2 0 0 0 0 0 0 1 0 0 1 0 0 1

1.3 0 0 0 0 0 0 0.6 0 0 0.6 0 0 0.6

42 9 61 14 15 15 28 8 8 10 11 9 12 18

26.3 5.6 38.1 8.8 9.4 9.4 17.5 5.0 5.0 6.3 6.9 5.6 7.5 11.3

keratoacanthomas were reported in two patients. One patient with metastatic melanoma was found to have a possible new primary melanoma. Pharmacokinetics PK results are summarized in Table 3. Plasma maximum concentration (Cmax) and area under the curve (AUC) increased with dose. At the QD MTD (150 mg using the DIC formulation) on Day 22, the mean Cmax was 2090 ng/mL (4 μM) and mean AUC was 18,200 h*ng/ mL. Steady state appeared to have been achieved by Day eight, and after repeated once-daily dosing, AUC on Day 22 was about 1.5-fold higher compared to Day one. High inter-subject variability in exposure was observed. For the QD dosing regimen (DIC formulation), plasma AUC and Cmax increased with increasing dose on Day 22. At the same equivalent daily dose on Day 22 (150 mg/day DIC formulation), the Q12H dosing regimen trended toward higher Cmax compared to the QD regimen. The FC formulation generally yielded higher plasma AUC compared to the DIC formulation (Q12H regimen) on Day 22. At 75 mg Q12H, the mean plasma AUC for the FC formulation was approximately 1.8-fold higher than for the DIC formulation on Day 22. Pretreatment with famotidine, which increases gastric pH, resulted in approximately 1.8-fold lower plasma AUC compared to fasted patients. The fed treatment did not result in

Invest New Drugs Table 3 Pharmacokinetic results at specific timepoints for patients organized by dose, schedule, and drug formulation. When data were not available for all patients in a cohort, the number of patients included in the analysis is indicated in parenthesis Dose (mg)

Day

Cmax (ng/mL)

AUC (hr*ng/mL)

mean

SD

mean

SD

5 3 3 3 3 1 3 3 6 5

260 421 394 397 949 438 1740 996 1550 1830

98.4 214 167 165 472 NA 2130 332 503 963

2290 2320 3670 3680 7160 4610 14100 8160 14500 18700

1230 800 1260 1590 1050 NA 16100 3790 3940 12400

1 83 22 58 (54) Fasted 8 18 Famotidine 15 15 (14) Fed 22 13 (12) 225 1 3 22 2 DIC formulation Q12H 50 1 4 (2) 22 2 75 1 8 22 5 100 1 5 22 3 FC formulation Q12H 25 1 4 22 3 50 1 4

2290 2530 2690 1240 3020 2040 2660

1620 1620 1410 680 1630 557 2500

18700 22800 33300 17800 32900 15700 23500

13300 17100 22200 14200 17600 6010 12600

1520 1020 1010 2280 881 1870

978 578 484 1190 237 887

7900 7160 7390 20200 6780 16600

1310 5400 3960 16500 2810 9320

1100 1460 1910

124 539 316

5570 8230 12300

1060 2700 3840

3160 3670 4810

972 1040 304

20600 20100 31700

5250 10500 19900

DIC Formulation QD 10 1 22 20 1 22 40 1 22 60 1 22 100 1 22

Number

150

75

22 1 22

3 5 2

Ki67 was also decreased to a lesser extent, to 69 % of baseline (95 % CI 58–83 %). In contrast, total ERK and total MEK were not substantially reduced. Examples of decreased pERK and pMEK staining are shown in Fig. 2. However despite the evidence of pathway inhibition, there was no observed association between change in these markers and change in tumor size or time on study treatment. Tumor response A waterfall plot showing maximum change in tumor size from baseline is shown in Fig. 3. This includes all patients evaluable for response and the two most common histologies, melanoma and colorectal cancer, are indicated by separate colors. Two patients had partial responses by RECIST: One papillary thyroid cancer with NRAS mutation (lasting 72 weeks) and one with uveal melanoma (unknown mutation status, lasting 44 weeks). Another nine patients had tumor decrease of at least 10 % but did not meet RECIST criteria for PR. These include six patients with melanoma (two with BRAF V600E mutation, one each with GNAQ, NRAS and HRAS mutations, one unknown); one patient with colorectal cancer with KRAS mutation; one patient with NSCLC (unknown mutation); and one patient with carcinoid. Several patients had prolonged stable disease on study suggesting possible clinical benefit. 21 patients were on study for 24 weeks of more. These include eight patients with papillary thyroid cancer (28 to 88 weeks; 1 BRAF mutation, one NRAS mutation, one HRAS mutation), six with melanoma (24 to 56 weeks; two BRAF mutation, one QNAQ mutation), three with NSCLC (27 to 40 weeks), two with carcinoid (24 and 55 weeks), and two with Hurthle cell carcinoma (24 and 172+ weeks).

Discussion a marked change in plasma AUC or Cmax compared to the fasted treatment. Pharmacodynamics Matched tumors pairs from 33 patients were studied for markers of RAF inhibition. Markers of RAF pathway activity were decreased significantly, as shown in Fig. 1. Compared to baseline, the mean levels were: pAKT 42 % (95 % CI 31–56 %), pERK 42 % (95 % CI 35–51 %), and pMEK 38 % (95 % CI 32–45 %).

XL281 is a generally well-tolerated orally bio-available RAF inhibitor. Objective responses and clinical benefit were seen in patients with tumors harboring mutations that activate the RAF pathway. These responses however were less frequent that expected from other selective RAF inhibitors. Among 18 patients with BRAF-mutant melanoma treated on this study, there were only two minor responses. In contrast, vemurafenib and dabrafenib both have reported response rates of over 50 % [9–12]. There are several possible explanations for this. Insufficient dosing is unlikely, since the dose

Invest New Drugs

Fig. 1 Summarized data for patients evaluated for treatment-related changes in pERK, total ERK, pMEK, total MEK, phAKT or Ki67. For each marker, individual subject data are plotted as the ratio to baseline. These ratios were summarized as the geometric mean and associated 95 % confidence intervals. The geometric mean ratio was tested for a

A

Melanoma pERK (red) DNA (blue) Day 20: -77%

B

Colorectal pMEK (red) DNA (blue) Day 18: -63%

Baseline

On Treatment

Fig. 2 Paired biopsies taken after XL281 therapy show reductions in pERK and pMEK in tumor tissue. a Biopsies taken at baseline and after 20 days of XL281 therapy from a patient with melanoma, and processed for pERK (red) and DNA stain (blue). After normalization to DNA content, pERK levels were reduced 77 % after treatment. b Biopsies taken at baseline and after 18 days of XL281 therapy from a patient with colorectal carcinoma, and processed for pMEK (red) and DNA stain (blue). After normalization to DNA content, pMEK levels were reduced 63 % in this patient

significant difference from 1.0 using a two-sided student’s t-test. Patients with no known driver mutation are shown with an open red symbol. Patients with known driver mutations are shown with blue symbols; filled blue symbols indicate a BRAF mutation, all other mutations are shown with open blue symbols

was escalated until treatment-emergent adverse events led to declaration of a maximum tolerated dose. Furthermore, the pharmacokinetic data show that that the doses administered here achieved peak plasma concentrations in the micromolar range, well in excess of the in vitro IC50. However XL281 is not a selective BRAF inhibitor. Thus the treatment-emergent toxicities that halted dose escalation may have been related to nonselective RAF kinase inhibition. Similarly, the tumor biopsies performed in a subset of patients show that the drug does inhibit the MEK-ERKAKT pathway to a degree. However the mean decrease in pERK of 52 % may have been insufficient to result in tumor regression. Tumor biopsies in patients with melanoma treated with vemurafenib suggested that pERK had to decrease by greater than 80 % to lead to tumor regression [13]. The low incidence of cutaneous SCC and keratoacanthomas in this study is also consistent with broader RAF specificity of XL281. The observed incidence of SCC/ KA in this study was 4 %, which is substantially lower than the reported incidence in selective BRAF inhibitors dabrafenib (6–10 %) and vemurafenib (18–26 %) [10, 9, 12, 11]. Taken together, the data suggest that non-selective RAF inhibition prevented dose escalation to a level that would

Invest New Drugs Fig. 3 Waterfall plot showing greatest change in tumor size for all patients evaluable for response

sufficiently inhibit oncogenic BRAF and lead to tumor regression. In contrast, the broad RAF inhibition by XL281 may explain the occasional responses seen in RAS-mutant cancers, which may require inhibition of multiple RAF isoforms.

Conflict of interest Two authors (D.O.C. and S.H.J.) are paid employees of the sponsor. All other authors declare no potential conflicts of interest.

5.

6.

7. Compliance with ethical standards All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

8.

Informed consent Informed consent was obtained from all individual participants included in the study. 9. Funding The study was sponsored by Exelixis.

References 10. 1. Kolch W, Kotwaliwale A, Vass K, Janosch P (2002) The role of Raf kinases in malignant transformation. Expert Rev Mol Med 4(8):1–18. doi:10.1017/S1462399402004386 2. Sebolt-Leopold JS, Herrera R (2004) Targeting the mitogen-activated protein kinase cascade to treat cancer. Nat Rev Cancer 4(12):937– 947. doi:10.1038/nrc1503 3. Bos JL (1989) ras oncogenes in human cancer: a review. Cancer Res 49(17):4682–4689 4. Davies H, Bignell GR, Cox C, Stephens P, Edkins S, Clegg S, Teague J, Woffendin H, Garnett MJ, Bottomley W, Davis N, Dicks E, Ewing R, Floyd Y, Gray K, Hall S, Hawes R, Hughes J, Kosmidou V, Menzies A, Mould C, Parker A, Stevens C, Watt S, Hooper S, Wilson R, Jayatilake H, Gusterson BA, Cooper C, Shipley J, Hargrave D, Pritchard-Jones K, Maitland N, Chenevix-Trench G, Riggins GJ, Bigner DD, Palmieri G, Cossu A, Flanagan A, Nicholson A, Ho JW, Leung SY, Yuen ST, Weber BL, Seigler HF,

11.

12.

Darrow TL, Paterson H, Marais R, Marshall CJ, Wooster R, Stratton MR, Futreal PA (2002) Mutations of the BRAF gene in human cancer. Nature 417(6892):949–954. doi:10.1038/nature00766 Satyamoorthy K, Li G, Gerrero MR, Brose MS, Volpe P, Weber BL, Van Belle P, Elder DE, Herlyn M (2003) Constitutive mitogenactivated protein kinase activation in melanoma is mediated by both BRAF mutations and autocrine growth factor stimulation. Cancer Res 63(4):756–759 Cohen Y, Xing M, Mambo E, Guo Z, Wu G, Trink B, Beller U, Westra WH, Ladenson PW, Sidransky D (2003) BRAF mutation in papillary thyroid carcinoma. J Natl Cancer Inst 95(8):625–627 Kimura ET, Nikiforova MN, Zhu Z, Knauf JA, Nikiforov YE, Fagin JA (2003) High prevalence of BRAF mutations in thyroid cancer: genetic evidence for constitutive activation of the RET/PTC-RASBRAF signaling pathway in papillary thyroid carcinoma. Cancer Res 63(7):1454–1457 Schwartz GK, Robertson S, Shen A, Wang E, Pace L, Dials H, Mendelson D, Shannon P, Gordon M (2009) A phase I study of XL281, a selective oral RAF kinase inhibitor, in patients with advanced solid tumors. J Clin Oncol 27(15s):abstr 3513 Sosman JA, Kim KB, Schuchter L, Gonzalez R, Pavlick AC, Weber JS, McArthur GA, Hutson TE, Moschos SJ, Flaherty KT, Hersey P, Kefford R, Lawrence D, Puzanov I, Lewis KD, Amaravadi RK, Chmielowski B, Lawrence HJ, Shyr Y, Ye F, Li J, Nolop KB, Lee RJ, Joe AK, Ribas A (2012) Survival in BRAF V600-mutant advanced melanoma treated with vemurafenib. N Engl J Med 366(8): 707–714. doi:10.1056/NEJMoa1112302 Chapman PB, Hauschild A, Robert C, Haanen JB, Ascierto P, Larkin J, Dummer R, Garbe C, Testori A, Maio M, Hogg D, Lorigan P, Lebbe C, Jouary T, Schadendorf D, Ribas A, O’Day SJ, Sosman JA, Kirkwood JM, Eggermont AM, Dreno B, Nolop K, Li J, Nelson B, Hou J, Lee RJ, Flaherty KT, McArthur GA, Group B-S (2011) Improved survival with vemurafenib in melanoma with BRAF V600E mutation. N Engl J Med 364(26):2507–2516. doi:10.1056/ NEJMoa1103782 Hauschild A, Grob JJ, Demidov LV, Jouary T, Gutzmer R, Millward M, Rutkowski P, Blank CU, Miller WH Jr, Kaempgen E, MartinAlgarra S, Karaszewska B, Mauch C, Chiarion-Sileni V, Martin AM, Swann S, Haney P, Mirakhur B, Guckert ME, Goodman V, Chapman PB (2012) Dabrafenib in BRAF-mutated metastatic melanoma: a multicentre, open-label, phase 3 randomised controlled trial. Lancet 380(9839):358–365. doi:10.1016/S0140-6736(12)60868-X Ascierto PA, Minor D, Ribas A, Lebbe C, O’Hagan A, Arya N, Guckert M, Schadendorf D, Kefford RF, Grob JJ, Hamid O,

Invest New Drugs Amaravadi R, Simeone E, Wilhelm T, Kim KB, Long GV, Martin AM, Mazumdar J, Goodman VL, Trefzer U (2013) Phase II trial (BREAK-2) of the BRAF inhibitor Dabrafenib (GSK2118436) in patients with metastatic melanoma. J Clin Oncol 31(26):3205–3211. doi:10.1200/JCO.2013.49.8691 13. Bollag G, Hirth P, Tsai J, Zhang J, Ibrahim PN, Cho H, Spevak W, Zhang C, Zhang Y, Habets G, Burton EA, Wong B, Tsang G, West

BL, Powell B, Shellooe R, Marimuthu A, Nguyen H, Zhang KY, Artis DR, Schlessinger J, Su F, Higgins B, Iyer R, D’Andrea K, Koehler A, Stumm M, Lin PS, Lee RJ, Grippo J, Puzanov I, Kim KB, Ribas A, McArthur GA, Sosman JA, Chapman PB, Flaherty KT, Xu X, Nathanson KL, Nolop K (2010) Clinical efficacy of a RAF inhibitor needs broad target blockade in BRAF-mutant melanoma. Nature 467(7315):596–599. doi:10.1038/nature09454