Response to Dabrafenib Plus Trametinib in a Patient With an Uncommon Activating BRAF Mutation: A First in Non-Small Cell Lung Cancer.

Mutations in BRAF are present in 4% of non-small cell lung cancer (NSCLC), of which half are well-characterized activating variants affecting codon 600 (classified as class I). These mutations, most commonly BRAF V600E, have been associated with response to BRAF/MEK-directed small molecule kinase inhibitors. NSCLC with kinase-activating BRAF mutations occurring at other codons (class II variants) represent a substantial portion of BRAF-mutated NSCLC, but use of targeted therapy in these tumors is still under investigation. Class II mutations have been described in other tumor types and have been associated with response to BRAF/MEK-targeted agents, although optimal treatment strategies for these patients are lacking. This report presents a case of a woman with metastatic NSCLC harboring a class II BRAF p.N486_P490del variant who had a sustained clinical response to combination therapy with dabrafenib and trametinib. This first report of the use of BRAF/MEK-targeted therapy for this variant in NSCLC supports consideration of such treatment for tumors with class II BRAF variants.

Acquired Resistance to First-Line Afatinib and the Challenges of Prearranged Progression Biopsies.

OBJECTIVES: The mechanisms of acquired resistance to the irreversible EGFR inhibitor afatinib are not well documented. We performed this prospective clinical trial to determine the prevalence of the mutation T790M in afatinib-resistant patients. METHODS: Eligible patients had EGFR mutations; they were tyrosine kinase inhibitor-naive and were treated with afatinib, 40 mg daily. At enrollment, patients consented to a future repeat biopsy at the time of acquired resistance. RESULTS: A total of 24 patients were enrolled. The objective response rate was 58% (95% confidence interval [CI]: 37-78) with a median progression-free survival of 11.4 months (95% CI: 5.9-13.7) and median overall survival of 20.8 months (95% CI: 15.1-40.5). Of the 24 patients enrolled, 23 progressed and only 14 completed repeat biopsy at time of progression, with 11 samples sufficient for molecular analysis. Of those 11 patients, four (36% [95% CI: 10.9-69.2]) harbored T790M. CONCLUSIONS: T790M is likely a common resistance mechanism in patients treated with first-line afatinib. Although repeat biopsies at progression are crucial in elucidating resistance mechanisms, this study suggests that clinical and technical issues often limit their feasibility, highlighting the importance of developing noninvasive tumor-genotyping strategies.

Neoadjuvant irinotecan, cisplatin, and concurrent radiation therapy with celecoxib for patients with locally advanced esophageal cancer.

BACKGROUND: Patients with locally advanced esophageal cancer who are treated with trimodality therapy have a high recurrence rate. Preclinical evidence suggests that inhibition of cyclooxygenase 2 (COX2) increases the effectiveness of chemoradiation, and observational studies in humans suggest that COX-2 inhibition may reduce esophageal cancer risk. This trial tested the safety and efficacy of combining a COX2 inhibitor, celecoxib, with neoadjuvant irinotecan/cisplatin chemoradiation. METHODS: This single arm phase 2 trial combined irinotecan, cisplatin, and celecoxib with concurrent radiation therapy. Patients with stage IIA-IVA esophageal cancer received weekly cisplatin 30 mg/m(2) plus irinotecan 65 mg/m(2) on weeks 1, 2, 4, and 5 concurrently with 5040 cGy of radiation therapy. Celecoxib 400 mg was taken orally twice daily during chemoradiation, up to 1 week before surgery, and for 6 months following surgery. RESULTS: Forty patients were enrolled with stage IIa (30 %), stage IIb (20 %), stage III (22.5 %), and stage IVA (27.5 %) esophageal or gastroesophageal junction cancer (AJCC, 5th Edition). During chemoradiation, grade 3-4 treatment-related toxicity included dysphagia (20 %), anorexia (17.5 %), dehydration (17.5 %), nausea (15 %), neutropenia (12.5 %), diarrhea (10 %), fatigue (7.5 %), and febrile neutropenia (7.5 %). The pathological complete response rate was 32.5 %. The median progression free survival was 15.7 months and the median overall survival was 34.7 months. 15 % (n = 6) of patients treated on this study developed brain metastases. CONCLUSIONS: The addition of celecoxib to neoadjuvant cisplatin-irinotecan chemoradiation was tolerable; however, overall survival appeared comparable to prior studies using neoadjuvant cisplatin-irinotecan chemoradiation alone. Further studies adding celecoxib to neoadjuvant chemoradiation in esophageal cancer are not warranted. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00137852 , registered August 29, 2005.

Improved tumor vascularization after anti-VEGF therapy with carboplatin and nab-paclitaxel associates with survival in lung cancer.

Addition of anti-VEGF antibody therapy to standard chemotherapies has improved survival and is an accepted standard of care for advanced non-small cell lung cancer (NSCLC). However, the mechanisms by which anti-VEGF therapy increases survival remain unclear. We evaluated dynamic CT-based vascular parameters and plasma cytokines after bevacizumab alone and after bevacizumab plus chemotherapy with carboplatin and nab-paclitaxel in advanced NSCLC patients to explore potential biomarkers of treatment response and resistance to this regimen. Thirty-six patients were enrolled in this study. The primary end point was 6-mo progression-free survival rate, which was 74% (95% CI: 57, 97). This regimen has a promising overall response rate of 36% and median time to progression of 8.5 (6.0, 38.7) mo and overall survival of 12.2 (9.6, 44.1) mo. We found that anti-VEGF therapy led to a sustained increase in plasma PlGF, a potential pharmacodynamic marker. We also found that higher levels of soluble VEGFR1 measured before starting bevacizumab with chemotherapy were associated with worse survival, supporting its potential role as biomarker of treatment resistance. Our imaging biomarker studies indicate that bevacizumab-based treatment-while reducing blood flow, volume, and permeability in the overall population-may be associated with improved survival in patients with improved tumor vasculature and blood perfusion after treatment. This hypothesis-generating study supports the notion that excessively decreasing vascular permeability and pruning/rarefaction after bevacizumab therapy may negatively impact the outcome of combination therapy in NSCLC patients. This hypothesis warrants further dose-titration studies of bevacizumab to examine the dose effect on tumor vasculature and treatment efficacy.

Neoadjuvant chemoradiotherapy for locally advanced thymic tumors: a phase II, multi-institutional clinical trial.

OBJECTIVE: To determine the response rate, toxicity, and rate of complete resection after induction chemoradiotherapy for locally advanced thymic tumors, which were defined by specific radiographic criteria. METHODS: A single-arm, pilot trial was conducted at 4 institutions. Patients with thymoma or thymic carcinoma who met specific criteria on computed tomography were accrued. Induction therapy consisted of 2 cycles of cisplatin and etoposide combined with 45 Gy of thoracic radiotherapy. Patients underwent computed tomography and positron emission tomography before and after induction therapy and then resection was attempted. Postoperative chemoradiotherapy was administered in selected patients. The primary endpoint was the pathologic response to induction therapy. The secondary endpoints were toxicity, surgical complications, radiographic response, and the rate of R0 resection. RESULTS: A total of 22 patients were accrued during a 5-year period (1 patient withdrew before starting induction therapy). Of the 22 patients, 21 completed induction therapy, and 9 (41%) experienced grade 3 or 4 toxicity. A total of 10 patients had a partial radiographic response and 11 had stable disease. Of the 21 patients, 17 (77%) underwent an R0 resection, 3 (14%) an R1 resection, and 1 (5%) underwent debulking. Eight patients sustained surgical complications (36%), and two patients (9%) died postoperatively. Of the 21 patients, 13 (62%) had either thymic carcinoma or B3 thymoma and 15 (71%) had either Masaoka stage III or IV disease. No patient had a complete pathologic response, but 5 specimens (24%) had <10% viable tumor. CONCLUSIONS: The present induction chemoradiotherapy protocol, which used specific computed tomography inclusion criteria to successfully select locally advanced thymic tumors, appeared to be tolerable and resulted in a high rate of complete surgical resection.

Potential of 18F-FDG PET toward personalized radiotherapy or chemoradiotherapy in lung cancer.

PURPOSE: We investigated the metabolic response of lung cancer to radiotherapy or chemoradiotherapy by (18)F-FDG PET and its utility in guiding timely supplementary therapy. METHODS: Glucose metabolic rate (MRglc) was measured in primary lung cancers during the 3 weeks before, and 10-12 days (S2), 3 months (S3), 6 months (S4), and 12 months (S5) after radiotherapy or chemoradiotherapy. The association between the lowest residual MRglc representing the maximum metabolic response (MRglc-MMR) and tumor control probability (TCP) at 12 months was modeled using logistic regression. RESULTS: We accrued 106 patients, of whom 61 completed the serial (18)F-FDG PET scans. The median values of MRglc at S2, S3 and S4 determined using a simplified kinetic method (SKM) were, respectively, 0.05, 0.06 and 0.07 µmol/min/g for tumors with local control and 0.12, 0.16 and 0.19 µmol/min/g for tumors with local failure, and the maximum standard uptake values (SUVmax) were 1.16, 1.33 and 1.45 for tumors with local control and 2.74, 2.74 and 4.07 for tumors with local failure (p < 0.0001). MRglc-MMR was realized at S2 (MRglc-S2) and the values corresponding to TCP 95 %, 90 % and 50 % were 0.036, 0.050 and 0.134 µmol/min/g using the SKM and 0.70, 0.91 and 1.95 using SUVmax, respectively. Probability cut-off values were generated for a given level of MRglc-S2 based on its predicted TCP, sensitivity and specificity, and MRglc ≤0.071 µmol/min/g and SUVmax ≤1.45 were determined as the optimum cut-off values for predicted TCP 80 %, sensitivity 100 % and specificity 63 %. CONCLUSION: The cut-off values (MRglc ≤0.071 µmol/min/g using the SKM and SUVmax ≤1.45) need to be tested for their utility in identifying patients with a high risk of residual cancer after standard dose radiotherapy or chemoradiotherapy and in guiding a timely supplementary dose of radiation or other means of salvage therapy.

A phase I study of erlotinib and hydroxychloroquine in advanced non-small-cell lung cancer.

INTRODUCTION: This investigator-initiated study explores the safety, maximum tolerated dose, clinical response, and pharmacokinetics of hydroxychloroquine (HCQ) with and without erlotinib in patients with advanced non-small-cell lung cancer. METHODS: Patients with prior clinical benefit from an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor were randomized to HCQ or HCQ plus erlotinib in a 3 + 3 dose-escalation schema. RESULTS: Twenty-seven patients were treated, eight with HCQ (arm A) and 19 with HCQ plus erlotinib (arm B). EGFR mutations were detected in 74% of the patients and 85% had received two or more prior therapies. Arm A had no dose-limiting toxicities, but the maximum tolerated dose was not reached as this arm closed early to increase overall study accrual. In arm B, one patient each experienced grade 3 rash, nail changes, skin changes, nausea, dehydration, and neutropenia; one had grade 4 anemia; and one developed fatal pneumonitis, all considered unrelated to HCQ. There were no dose-limiting toxicities, therefore the highest tested dose for HCQ with erlotinib 150 mg was 1000 mg daily. One patient had a partial response to erlotinib/HCQ, for an overall response rate of 5% (95% confidence interval, 1-25). This patient had an EGFR mutation and remained on therapy for 20 months. Administration of HCQ did not alter the pharmacokinetics of erlotinib. CONCLUSIONS: HCQ with or without erlotinib was safe and well tolerated. The recommended phase 2 dose of HCQ was 1000 mg when given in combination with erlotinib 150 mg.

Lung cancers with acquired resistance to EGFR inhibitors occasionally harbor BRAF gene mutations but lack mutations in KRAS, NRAS, or MEK1.

Acquired resistance to EGF receptor (EGFR) tyrosine kinase inhibitors (TKIs) is inevitable in metastatic EGFR-mutant lung cancers. Here, we modeled disease progression using EGFR-mutant human tumor cell lines. Although five of six models displayed alterations already found in humans, one harbored an unexpected secondary NRAS Q61K mutation; resistant cells were sensitive to concurrent EGFR and MEK inhibition but to neither alone. Prompted by this finding and because RAS/RAF/MEK mutations are known mediators of acquired resistance in other solid tumors (colon cancers, gastrointestinal stromal tumors, and melanomas) responsive to targeted therapies, we analyzed the frequency of secondary KRAS/NRAS/BRAF/MEK1 gene mutations in the largest collection to date of lung cancers with acquired resistance to EGFR TKIs. No recurrent NRAS, KRAS, or MEK1 mutations were found in 212, 195, or 146 patient samples, respectively, but 2 of 195 (1%) were found to have mutations in BRAF (G469A and V600E). Ectopic expression of mutant NRAS or BRAF in drug-sensitive EGFR-mutant cells conferred resistance to EGFR TKIs that was overcome by addition of a MEK inhibitor. Collectively, these positive and negative results provide deeper insight into mechanisms of acquired resistance to EGFR TKIs in lung cancer and inform ongoing clinical trials designed to overcome resistance. In the context of emerging knowledge about mechanisms of acquired resistance to targeted therapies in various cancers, our data highlight the notion that, even though solid tumors share common signaling cascades, mediators of acquired resistance must be elucidated for each disease separately in the context of treatment.

Genotypic and histological evolution of lung cancers acquiring resistance to EGFR inhibitors.

Lung cancers harboring mutations in the epidermal growth factor receptor (EGFR) respond to EGFR tyrosine kinase inhibitors, but drug resistance invariably emerges. To elucidate mechanisms of acquired drug resistance, we performed systematic genetic and histological analyses of tumor biopsies from 37 patients with drug-resistant non-small cell lung cancers (NSCLCs) carrying EGFR mutations. All drug-resistant tumors retained their original activating EGFR mutations, and some acquired known mechanisms of resistance including the EGFR T790M mutation or MET gene amplification. Some resistant cancers showed unexpected genetic changes including EGFR amplification and mutations in the PIK3CA gene, whereas others underwent a pronounced epithelial-to-mesenchymal transition. Surprisingly, five resistant tumors (14%) transformed from NSCLC into small cell lung cancer (SCLC) and were sensitive to standard SCLC treatments. In three patients, serial biopsies revealed that genetic mechanisms of resistance were lost in the absence of the continued selective pressure of EGFR inhibitor treatment, and such cancers were sensitive to a second round of treatment with EGFR inhibitors. Collectively, these results deepen our understanding of resistance to EGFR inhibitors and underscore the importance of repeatedly assessing cancers throughout the course of the disease.

Strategies for prolonged therapy in patients with advanced non-small-cell lung cancer.

PURPOSE: A key challenge in the treatment of advanced non-small-cell lung cancer (NSCLC) is improving outcomes for patients who have achieved at least stable disease after standard first-line therapy. Although current guidelines recommend a maximum of six cycles of first-line therapy, even in responding patients, recent trials have shown benefit with maintenance therapy. METHODS: We reviewed the English literature for randomized controlled trials on prolonged therapy for NSCLC conducted between January 1999 and January 2010. The search was supplemented by a review of abstracts presented at the American Society of Clinical Oncology annual meetings (2004 to 2010), the World Lung Cancer Conference (2007 to 2009), and the 2009 Joint European CanCer Organisation-European Society for Medical Oncology conference. RESULTS: Several alternative strategies for prolongation of chemotherapy have been tested: these can be broadly categorized as continuation (prolongation of the first-line regimen until disease progression, unacceptable toxicity, or administration of a predefined greater number of treatment cycles), switch-maintenance (administration of an active agent immediately after completion of the initial course of chemotherapy), and continuation-maintenance (ongoing administration of a lower intensity version of the first-line chemotherapy regimen). These approaches differ from traditional second line, which is defined as treatment administered after documented clinical progression subsequent to first-line therapy. CONCLUSION: There are no data to support continuation chemotherapy in advanced NSCLC. Switch-maintenance trials with erlotinib and pemetrexed have demonstrated an improvement in overall survival. Thus far, continuation-maintenance has shown an improvement in progression-free survival, without an overall survival advantage.

Cetuximab monotherapy in patients with advanced non-small cell lung cancer after prior epidermal growth factor receptor tyrosine kinase inhibitor therapy.

INTRODUCTION: Therapeutic agents directed against the epidermal growth factor receptor (EGFR) signaling pathway have been effective in the treatment of non-small cell lung cancer (NSCLC). Cetuximab is a monoclonal antibody against the EGFR receptor with antitumor activity in NSCLC. This study evaluated the efficacy of cetuximab monotherapy after prior treatment with an oral EGFR tyrosine kinase inhibitor (TKI). METHODS: Eligible patients had stage IIIB, IV, or recurrent NSCLC with progression on the oral EGFR TKIs gefitinib or erlotinib. Cetuximab was administered intravenously at 400 mg/m on day 1 and then 250 mg/m weekly until disease progression or unacceptable toxicity. The primary end point was response rate. RESULTS: Eighteen patients were enrolled. Patients were heavily pretreated with chemotherapy and TKIs (average number of treatments = 4.2). The response rate was 0/18 (0%), and 28% of patients had confirmed stable disease. Median progression-free survival was 1.8 months (95% confidence interval, 1.6-5.4 months), and median overall survival was 7.5 months (95% confidence interval, 2.2-19 months). Three patients harbored activating EGFR mutations, and one of them had stable disease for nearly 6 months on cetuximab. Common toxicities were mild and included fatigue, skin rash, and nausea/vomiting. Two patients developed interstitial lung disease, life threatening in one case. CONCLUSIONS: Cetuximab monotherapy administered after prior EGFR TKI treatment in patients with advanced NSCLC does not yield clinical responses.

Anaplastic lymphoma kinase inhibition in non-small-cell lung cancer.

BACKGROUND: Oncogenic fusion genes consisting of EML4 and anaplastic lymphoma kinase (ALK) are present in a subgroup of non-small-cell lung cancers, representing 2 to 7% of such tumors. We explored the therapeutic efficacy of inhibiting ALK in such tumors in an early-phase clinical trial of crizotinib (PF-02341066), an orally available small-molecule inhibitor of the ALK tyrosine kinase. METHODS: After screening tumor samples from approximately 1500 patients with non-small-cell lung cancer for the presence of ALK rearrangements, we identified 82 patients with advanced ALK-positive disease who were eligible for the clinical trial. Most of the patients had received previous treatment. These patients were enrolled in an expanded cohort study instituted after phase 1 dose escalation had established a recommended crizotinib dose of 250 mg twice daily in 28-day cycles. Patients were assessed for adverse events and response to therapy. RESULTS: Patients with ALK rearrangements tended to be younger than those without the rearrangements, and most of the patients had little or no exposure to tobacco and had adenocarcinomas. At a mean treatment duration of 6.4 months, the overall response rate was 57% (47 of 82 patients, with 46 confirmed partial responses and 1 confirmed complete response); 27 patients (33%) had stable disease. A total of 63 of 82 patients (77%) were continuing to receive crizotinib at the time of data cutoff, and the estimated probability of 6-month progression-free survival was 72%, with no median for the study reached. The drug resulted in grade 1 or 2 (mild) gastrointestinal side effects. CONCLUSIONS: The inhibition of ALK in lung tumors with the ALK rearrangement resulted in tumor shrinkage or stable disease in most patients. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT00585195.).

Phase I/II study of AT-101 with topotecan in relapsed and refractory small cell lung cancer.

INTRODUCTION: AT-101 is an oral, pan Bcl-2 family protein inhibitor that has demonstrated activity in small cell lung cancer (SCLC) models. A phase I/II study was conducted combining AT-101 with topotecan in relapsed and refractory SCLC. METHODS: An open-labeled multicenter phase I/II study was conducted of oral AT-101 with intravenous topotecan in patients with SCLC who had progressed on prior platinum-containing chemotherapy. The phase II portion was a two-stage design, and two cohorts of patients, sensitive relapsed and refractory, were analyzed. Primary endpoint in the two-stage phase II portion was response rate; secondary endpoints were duration of response and time to progression. RESULTS: Thirty-six patients were enrolled. The most common toxicities were hematologic, as would be expected with topotecan and AT-101. The recommended phase II dose was 40 mg AT-101 days 1 to 5 with topotecan 1.25 mg/m(2) days 1 to 5 on a 21-day cycle. In the sensitive-relapsed cohort (n = 18), there were 0 complete response (CR), three partial response (PR), 10 stable disease (SD), and four progressive disease (PD). In the refractory cohort (n = 12), there were 0 CR/PR, five SD, and five PD. The study did not meet its prespecified endpoints to continue enrollment in the second stage of the phase II study. Median time to progression in the sensitive-relapsed cohort was 17.4 weeks and 11.7 weeks in the refractory cohort. CONCLUSIONS: AT-101 can be safely combined with topotecan at a reduced dose of 1.25 mg/m(2). The response rates observed did not meet the criteria for additional enrollment; however, many patients had a best response of SD and the median time to progression in both cohorts was favorable. Additional trials of AT-101 in SCLC are ongoing.

Phase I study of the c-raf-1 antisense oligonucleotide ISIS 5132 in combination with carboplatin and paclitaxel in patients with previously untreated, advanced non-small cell lung cancer.

BACKGROUND: A phase I trial was performed to evaluate the administration of carboplatin/paclitaxel in combination with ISIS-5132, a phosphorothioate antisense oligodeoxynucleotide inhibitor of c-raf-1 kinase expression, in patients with advanced non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Previously untreated patients with stage IIIB/IV NSCLC received ISIS 5132 by continuous intravenous infusion at 2.0 mg/kg/d for 14 days. Starting doses were paclitaxel 175 mg/m(2) and carboplatin targeting an area under the free platinum plasma concentration-time curve (AUC(fp)) of 5 mg . min/ml (dose level 1). The carboplatin dose was then increased to AUC(fp) 6 mg . min/ml (dose level 2) after which the paclitaxel dose was increased to 200 mg/m(2) (dose level 3). The maximum tolerated dose was established by toxicity during the first two 21-day cycles of therapy. The pharmacokinetics of all three agents was determined before and during the ISIS 5132 infusion. RESULTS: Thirteen patients were treated with the carboplatin/paclitaxel/ISIS 5132 combination. Dose-limiting neutropenia occurred in two patients at dose level 3. Grade 3 and 4 nonhematologic toxicities were infrequent and limited to nausea and constipation. The maximum tolerated doses were carboplatin AUC(fp) 6 mg . min/ml, paclitaxel 175 mg/m(2), and ISIS 5132 2.0 mg/kg/d for 14 days. There were no objective responses and the concurrent infusion of ISIS 5132 did not alter the plasma pharmacokinetics of paclitaxel or total platinum. CONCLUSION: ISIS 5132 can be safely combined with standard doses of carboplatin and paclitaxel. Combining cytotoxic chemotherapeutic agents with inhibitors of aberrant signal transduction mediated by Raf proteins produced no objective responses in the dose and schedule administered in this study.

Brief report of biweekly pemetrexed and gemcitabine in elderly patients with non-small cell lung cancer.

We examined a nonplatinum-based doublet chemotherapy regimen, pemetrexed and gemcitabine given on a biweekly (every 14 days) schedule, in patients older than 70 years with newly diagnosed advanced non-small cell lung cancer. The study was closed after nine patients were treated due to excess toxicity, primarily fatigue, and nonneutropenic infection. No responses were observed. Eight of the nine patients were hospitalized during therapy and seven discontinued treatment for reasons other than progressive disease. Median progression-free survival was 1.7 months, and median overall survival was 3.9 months. We found that biweekly pemetrexed and gemcitabine was too toxic in our cohort of elderly patients with newly diagnosed advanced non-small cell lung cancer.