Michelle Casey

Improved Survival with MEK Inhibition in BRAF-Mutated Melanoma

BACKGROUND Activating mutations in serine-threonine protein kinase B-RAF (BRAF) are found in 50% of patients with advanced melanoma. Selective BRAF-inhibitor therapy improves survival, as compared with chemotherapy, but responses are often short-lived. In previous trials, MEK inhibition appeared to be promising in this population. METHODS In this phase 3 open-label trial, we randomly assigned 322 patients who had metastatic melanoma with a V600E or V600K BRAF mutation to receive either trametinib, an oral selective MEK inhibitor, or chemotherapy in a 2:1 ratio. Patients received trametinib (2 mg orally) once daily or intravenous dacarbazine (1000 mg per square meter of body-surface area) or paclitaxel (175 mg per square meter) every 3 weeks. Patients in the chemotherapy group who had disease progression were permitted to cross over to receive trametinib. Progression-free survival was the primary end point, and overall survival was a secondary end point. RESULTS Median progression-free survival was 4.8 months in the trametinib group and 1.5 months in the chemotherapy group (hazard ratio for disease progression or death in the trametinib group, 0.45; 95% confidence interval [CI], 0.33 to 0.63; P<0.001). At 6 months, the rate of overall survival was 81% in the trametinib group and 67% in the chemotherapy group despite crossover (hazard ratio for death, 0.54; 95% CI, 0.32 to 0.92; P=0.01). Rash, diarrhea, and peripheral edema were the most common toxic effects in the trametinib group and were managed with dose interruption and dose reduction; asymptomatic and reversible reduction in the cardiac ejection fraction and ocular toxic effects occurred infrequently. Secondary skin neoplasms were not observed. CONCLUSIONS Trametinib, as compared with chemotherapy, improved rates of progression-free and overall survival among patients who had metastatic melanoma with a BRAF V600E or V600K mutation. (Funded by GlaxoSmithKline; METRIC ClinicalTrials.gov number, NCT01245062.).

Combined BRAF and MEK Inhibition versus BRAF Inhibition Alone in Melanoma

BACKGROUND Combined BRAF and MEK inhibition, as compared with BRAF inhibition alone, delays the emergence of resistance and reduces toxic effects in patients who have melanoma with BRAF V600E or V600K mutations. METHODS In this phase 3 trial, we randomly assigned 423 previously untreated patients who had unresectable stage IIIC or stage IV melanoma with a BRAF V600E or V600K mutation to receive a combination of dabrafenib (150 mg orally twice daily) and trametinib (2 mg orally once daily) or dabrafenib and placebo. The primary end point was progression-free survival. Secondary end points included overall survival, response rate, response duration, and safety. A preplanned interim overall survival analysis was conducted. RESULTS The median progression-free survival was 9.3 months in the dabrafenib-trametinib group and 8.8 months in the dabrafenib-only group (hazard ratio for progression or death in the dabrafenib-trametinib group, 0.75; 95% confidence interval [CI], 0.57 to 0.99; P=0.03). The overall response rate was 67% in the dabrafenib-trametinib group and 51% in the dabrafenib-only group (P=0.002). At 6 months, the interim overall survival rate was 93% with dabrafenib-trametinib and 85% with dabrafenib alone (hazard ratio for death, 0.63; 95% CI, 0.42 to 0.94; P=0.02). However, a specified efficacy-stopping boundary (two-sided P=0.00028) was not crossed. Rates of adverse events were similar in the two groups, although more dose modifications occurred in the dabrafenib-trametinib group. The rate of cutaneous squamous-cell carcinoma was lower in the dabrafenib-trametinib group than in the dabrafenib-only group (2% vs. 9%), whereas pyrexia occurred in more patients (51% vs. 28%) and was more often severe (grade 3, 6% vs. 2%) in the dabrafenib-trametinib group. CONCLUSIONS A combination of dabrafenib and trametinib, as compared with dabrafenib alone, improved the rate of progression-free survival in previously untreated patients who had metastatic melanoma with BRAF V600E or V600K mutations. (Funded by GlaxoSmithKline; Clinical Trials.gov number, NCT01584648.).

Lapatinib Plus Capecitabine in Women with HER-2–Positive Advanced Breast Cancer: Final Survival Analysis of a Phase III Randomized Trial

The article presents final analyses of overall survival from a phase III trial of lapatinib and capecitabine in patients with human epidermal growth factor receptor 2–positive locally advanced or metastatic breast cancer that progressed following prior therapy including trastuzumab.

Correlation of BRAF Mutation Status in Circulating-Free DNA and Tumor and Association with Clinical Outcome across Four BRAFi and MEKi Clinical Trials

Purpose: Tumor-derived circulating cell–free DNA (cfDNA) is a potential alternative source from which to derive tumor mutation status. cfDNA data from four clinical studies of the BRAF inhibitor (BRAFi) dabrafenib or the MEK inhibitor (MEKi) trametinib were analyzed to determine the association between BRAF mutation status in cfDNA and tumor tissue, and the association of BRAF cfDNA mutation status with baseline factors and clinical outcome. Experimental Design: Patients with BRAF V600 mutation–positive melanoma were enrolled in each study after central confirmation of BRAF status in tumor using a PCR-based assay. BRAF mutation status in cfDNA from patient plasma collected at baseline, 732 of 836 (88%) enrolled patients in total, was determined. Results: BRAF mutations were detectable in cfDNA in 76% and 81% of patients with BRAF V600E/V600K–positive tumors, respectively. Patients negative for BRAF mutations in cfDNA had longer progression-free survival (PFS) and overall survival in each of the four studies, compared with patients with detectable cfDNA BRAF mutations. The presence of BRAF-mutant cfDNA was an independent prognostic factor for PFS after multivariate adjustment for baseline factors in three of four studies. Patients negative for BRAF mutation–positive cfDNA in plasma had higher response rates to dabrafenib and trametinib. Conclusions: BRAF mutations in cfDNA are detectable in >75% of late-stage melanoma patients with BRAF mutation–positive tumors. The lack of circulating, BRAF mutation–positive cfDNA is clinically significant for metastatic melanoma patients, and may be a prognostic marker for better disease outcome. Clin Cancer Res; 22(3); 567–74. ©2015 AACR.

Health-related quality of life impact in a randomised phase III study of the combination of dabrafenib and trametinib versus dabrafenib monotherapy in patients with BRAF V600 metastatic melanoma

AIM To present the impact of treatments on health-related quality of life (HRQoL) from the double-blind, randomised phase III COMBI-d study that investigated the combination of dabrafenib and trametinib versus dabrafenib monotherapy in patients with BRAF V600E/K-mutant metastatic melanoma. COMBI-d showed significantly prolonged progression-free survival for the combination. METHODS HRQoL was evaluated using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30, a generic cancer questionnaire (completed at baseline, during study treatment, at progression and post progression) assessing various dimensions (global health/QoL, functional status, and symptom impact). A mixed-model, repeated-measures analyses of covariance evaluated differences between arms. RESULTS Questionnaire completion rates were >95% at baseline, >85% to week 40 and >70% at disease progression. Baseline scores across both arms were comparable for all dimensions. Global health dimension scores were significantly better at weeks 8, 16 and 24 for patients receiving the combination during treatment and at progression. The majority of functional dimension scores (physical, social, role, emotional and cognitive functioning) trended in favour of the combination. Pain scores were significantly improved and clinically meaningful (6-13 point difference) for patients receiving the combination for all follow-up assessments versus those receiving dabrafenib monotherapy. For other symptom dimensions (nausea and vomiting, diarrhoea, dyspnoea, and constipation), scores trended in favour of dabrafenib monotherapy. CONCLUSION This analysis demonstrates that the combination of dabrafenib and trametinib provides better preservation of HRQoL and pain improvements versus dabrafenib monotherapy while also delaying progression. (Clinicaltrials.gov registration number: NCT01584648).

Updated Survival Analysis of a Randomized Study of Lapatinib Alone or in Combination with Trastuzumab in Women with HER2-Positive Metastatic Breast Cancer Progressing on Trastuzumab Therapy.

Background: The synergistic interaction of lapatinib combined with trastuzumab was established in HER2-positive preclinical models, hence providing the rationale to evaluate this combination in a clinical setting. Progression-free survival (PFS) from study EGF104900 revealed the combination of lapatinib plus trastuzumab was superior to lapatinib alone in women with HER2-positive metastatic breast cancer (MBC) that progressed on multiple lines of trastuzumab-based therapy. Preliminary data showed a trend in overall survival (OS) favoring the combination therapy; however, data were not mature. Updated OS analyses are reported.Methods: Women with HER2-positive MBC progressing on prior trastuzumab-containing regimens were randomized to receive either lapatinib 1500 mg once daily or lapatinib 1000 mg once daily in combination with trastuzumab 2 mg/kg (after a 4-mg/kg loading dose). If objective disease progression occurred on or after 4 weeks of lapatinib alone, crossover to the combination arm was permitted. OS was summarized using Kaplan-Meier curves and compared between treatment arms using stratified log-rank tests. Analyses adjusting for baseline prognostic factors and crossover were also performed.Results: 296 women were randomized (148 per arm). The median number of prior trastuzumab-containing regimens for MBC treatment was 3. Of the women randomized to lapatinib alone, 52% (77/148) crossed over to the combination arm. At data cut-off for updated OS, 218 deaths (74%) had occurred. Median OS following treatment with lapatinib plus trastuzumab was 60.7 weeks compared with 41.4 weeks for lapatinib alone. A significant improvement in OS was demonstrated with combination therapy compared with lapatinib monotherapy (HR: 0.74; 95% CI: 0.57, 0.97; P=.026). The survival benefit was maintained after adjusting for baseline prognostic factors (HR: 0.71; 95% CI: 0.54, 0.93; P=.012). A trend toward a clinically relevant 25% reduction in risk of death (P=.080) was also observed after adjusting for crossover.Conclusion: A statistically significant OS benefit was observed in women with heavily pretreated, HER2-positive MBC treated with lapatinib in combination with trastuzumab compared with those treated with lapatinib alone. The actual survival benefit of the combination therapy may be underestimated due to the high frequency of crossover. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 61.

Detecting Interaction(s) and Assessing the Impact of Component Subsets in a Chemical Mixture Using Fixed-Ratio Mixture Ray Designs

An important environmental and regulatory issue is the protection of human health from potential adverse effects of cumulative exposure to multiple chemicals. Earlier literature suggested restricting inference to specific fixed-ratio rays of interest. Based on appropriate definitions of additivity, single chemical data are used to predict the relationship among the chemicals under the zero-interaction case. Parametric comparisons between the additivity model and the model fit along the fixed-ratio ray(s) are used to detect departure from additivity. Collection of data along reduced fixed-ratio rays, where subsets of chemicals of interest are removed from the mixture and the remaining compounds are at the same relative ratios as considered in the full ray, allow researchers to make inference about the effect of the removed chemicals. Methods for fitting simultaneous confidence bands about the difference between the best fitting model and the model predicted under additivity are developed to identify regions along the rays where significant interactions occur. This general approach is termed the “single chemicals required” (SCR) method of analysis. A second approach, termed “single chemicals not required” (SCNR) method of analysis, is based on underlying assumptions about the parameterization of the response surface. Under general assumptions, polynomial terms for models fit along fixed-ratio rays are associated with interaction terms. Consideration is given to the case where only data along the mixture rays are available. Tests of hypotheses, which consider interactions due to subsets of chemicals, are also developed.

Randomized phase II study of axitinib versus placebo plus best supportive care in second-line treatment of advanced hepatocellular carcinoma

BACKGROUND The efficacy and safety of axitinib, a potent and selective vascular endothelial growth factor receptors 1-3 inhibitor, combined with best supportive care (BSC) was evaluated in a global, randomized, placebo-controlled phase II trial in patients with locally advanced or metastatic hepatocellular carcinoma (HCC). PATIENTS AND METHODS Patients with HCC and Child-Pugh Class A who progressed on or were intolerant to one prior antiangiogenic therapy were stratified by tumour invasion (presence/absence of extrahepatic spread and/or vascular invasion) and region (Asian/non-Asian) and randomized (2:1) to axitinib/BSC (starting dose 5 mg twice-daily) or placebo/BSC. The primary end point was overall survival (OS). RESULTS The estimated hazard ratio for OS was 0.907 [95% confidence interval (CI) 0.646-1.274; one-sided stratified P = 0.287] for axitinib/BSC (n = 134) versus placebo/BSC (n = 68), with the median (95% CI) of 12.7 (10.2-14.9) versus 9.7 (5.9-11.8) months, respectively. Results of prespecified subgroup analyses in Asian versus non-Asian patients or presence versus absence of tumour invasion were consistent with the overall population. Improvements favouring axitinib/BSC (P < 0.01) were observed in secondary efficacy end point analyses [progression-free survival (PFS), time to tumour progression (TTP), and clinical benefit rate (CBR)], and were retained among Asian patients in the prespecified subgroup analyses. Overall response rate did not differ significantly between treatments and patient-reported outcomes favoured placebo/BSC. Most common all-causality adverse events with axitinib/BSC were diarrhoea (54%), hypertension (54%), and decreased appetite (47%). Baseline serum analyses identified potential new prognostic (interleukin-6, E-selectin, interleukin-8, angiopoietin-2, migration inhibitory factor, and c-MET) or predictive (E-selectin and stromal-derived factor-1) factors for survival. CONCLUSIONS Axitinib/BSC did not improve OS over placebo/BSC in the overall population or in stratification subgroups. However, axitinib/BSC resulted in significantly longer PFS and TTP and higher CBR, with acceptable toxicity in patients with advanced HCC. TRIAL REGISTRATION ClinicalTrials.gov, NCT01210495.

METRIC phase III study: Efficacy of trametinib (T), a potent and selective MEK inhibitor (MEKi), in progression-free survival (PFS) and overall survival (OS), compared with chemotherapy (C) in patients (pts) with BRAFV600E/K mutant advanced or metastatic melanoma (MM).

LBA8509 Background: Dacarbazine (D) and paclitaxel (P) have been used to treat MM pts with limited effect. The MM treatment landscape has recently changed with the approval of vemurafenib and ipilimumab in 2011, but secondary malignancies or other toxicities are of concerns. T is a reversible, highly selective allosteric inhibitor of MEK1/2 activation and kinase activity. In a PhII trial (NCT01037127), pts with BRAFV600E mutation MM had median PFS of 5.3 mos. This PhIII trial (NCT01245062) was conducted in pts with BRAFV600E/K mutant advanced or MM. METHODS Pts were randomized 2:1 to T (2mg QD) or C (D or P). Pts were stratified by baseline LDH level and prior C; pts in the C arm were allowed to crossover to receive T after confirmation of PD. Primary endpoint was PFS in pts with BRAFV600E mutation-positive MM and no prior brain mets; secondary endpoints were OS, ORR and safety in primary and ITT. PFS and OS were compared using a stratified log-rank test. The study was designed with ≥99% power and one-sided α = 0.025 to detect 57% reduction in the risk of PD or death in pts treated with T vs C. RESULTS Between Dec 2010 and Jul 2011, 322 pts were randomized to T (n=214) or C (n=108); 273 pts were BRAFV600E mutation-positive with no prior brain mets. HR for primary population for PFS by investigator was 0.44 (95% CI 0.31-0.64; p<0.0001) in favor of T with a median PFS of 4.8 mo vs 1.4 mo with C. PFS benefit in favor of T was observed in ITT; this was confirmed by an independent review. The confirmed ORR was 24% with T and 7% with C. HR for interim OS was 0.53 (95% CI 0.30-0.94; p=0.0181), in favor of T in primary population. OS benefit was consistent in ITT pop despite 51 pts crossover from C to T. The most frequent AEs with T were skin rash, diarrhea, edema, hypertension, fatigue. Known MEKi class effects were observed, e.g. chorioretinopathy (<1%) and decreased ejection fraction (7%). Grade 3 AEs in T arm were hypertenstion (12%) and rash (7%). CONCLUSIONS T is the first in class MEKi associated with a significant improvement of PFS and OS compared to C in pts with BRAFV600E/K mutant MM.

Adjuvant Sunitinib for High-risk Renal Cell Carcinoma After Nephrectomy: Subgroup Analyses and Updated Overall Survival Results

BACKGROUND Adjuvant sunitinib significantly improved disease-free survival (DFS) versus placebo in patients with locoregional renal cell carcinoma (RCC) at high risk of recurrence after nephrectomy (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.59-0.98; p=0.03). OBJECTIVE To report the relationship between baseline factors and DFS, pattern of recurrence, and updated overall survival (OS). DESIGN, SETTING, AND PARTICIPANTS Data for 615 patients randomized to sunitinib (n=309) or placebo (n=306) in the S-TRAC trial. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Subgroup DFS analyses by baseline risk factors were conducted using a Cox proportional hazards model. Baseline risk factors included: modified University of California Los Angeles integrated staging system criteria, age, gender, Eastern Cooperative Oncology Group performance status (ECOG PS), weight, neutrophil-to-lymphocyte ratio (NLR), and Fuhrman grade. RESULTS AND LIMITATIONS Of 615 patients, 97 and 122 in the sunitinib and placebo arms developed metastatic disease, with the most common sites of distant recurrence being lung (40 and 49), lymph node (21 and 26), and liver (11 and 14), respectively. A benefit of adjuvant sunitinib over placebo was observed across subgroups, including: higher risk (T3, no or undetermined nodal involvement, Fuhrman grade ≥2, ECOG PS ≥1, T4 and/or nodal involvement; hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.55-0.99; p=0.04), NLR ≤3 (HR 0.72, 95% CI 0.54-0.95; p=0.02), and Fuhrman grade 3/4 (HR 0.73, 95% CI 0.55-0.98; p=0.04). All subgroup analyses were exploratory, and no adjustments for multiplicity were made. Median OS was not reached in either arm (HR 0.92, 95% CI 0.66-1.28; p=0.6); 67 and 74 patients died in the sunitinib and placebo arms, respectively. CONCLUSIONS A benefit of adjuvant sunitinib over placebo was observed across subgroups. The results are consistent with the primary analysis, which showed a benefit for adjuvant sunitinib in patients at high risk of recurrent RCC after nephrectomy. PATIENT SUMMARY Most subgroups of patients at high risk of recurrent renal cell carcinoma after nephrectomy experienced a clinical benefit with adjuvant sunitinib. TRIAL REGISTRATION ClinicalTrials.gov NCT00375674.