Variability in lung cancer response to ALK inhibitors cannot be explained by the diversity of ALK fusion variants.

Multiple laboratory evidences indicate that distinct variants of ALK translocations differ in their biochemical properties and responsiveness to ALK tyrosine kinase inhibitors (TKIs). These data are supported by some clinical studies, which showed improved responses to crizotinib in non-small cell lung cancer (NSCLC) patients carrying particular variants of ALK translocation. We retrospectively considered 64 Russian patients with ALK-rearranged NSCLC, who were treated by crizotinib (n = 23), ceritinib (n = 39) or alectinib (n = 2). ALK fusion variants were genotyped by PCR. Median progression-free survival (PFS) approached to 18 and 21 months in subjects with "short" (v.3a/b, v.5a/b) vs. "long" (TAPE-domain containing) fusion variants (p = 0.783), respectively; similar data were obtained while comparing EML4/ALK variant 1 vs. other ALK translocations (19 and 21 months, respectively; p = 0.604). Objective response rates were also strikingly similar in the above groups ("short": 88%, "long": 77%, p = 0.479; variant 1: 76%, other translocations: 81%, p = 0.753). Furthermore, ALK variants did not influence the disease outcomes when patients treated by crizotinib and ceritinib were analyzed separately. Overall, PFS on ALK TKI did not depend on whether the drug was administered upfront or after chemotherapy. Ceritinib produced significantly longer PFS than crizotinib (p = 0.022). In conclusion, this study revealed that distinct ALK translocation variants render similar clinical responsiveness to ALK inhibitors.

EGFR T790M Mutation in TKI-Naïve Clinical Samples: Frequency, Tissue Mosaicism, Predictive Value and Awareness on Artifacts.

BACKGROUND: This study evaluated the distribution of epidermal growth factor receptor (EGFR) T790M mutations in treatment-naïve tumor and normal samples obtained from cancer patients. METHODS: We utilized allele-specific PCR (AS-PCR), digital droplet PCR (ddPCR) and next generation sequencing (NGS) to detect EGFR T790M allele in several collections of tumor and normal human tissues. RESULTS: AS-PCR analysis of treatment-naïve tumor samples revealed somatic T790M mutation in 3/394 (1%) non-small cell lung carcinomas (NSCLC) carrying the tyrosine kinase inhibitor (TKI)-sensitizing EGFR mutation, but in none of 334 NSCLC lacking EGFR exon 19 deletions (ex19del) or L858R substitutions and in none of 235 non-lung tumors. Use of highly sensitive and quantitative assays, such as ddPCR and NGS, produced a high number of T790M-specific signals even in presumably T790M-negative DNA specimens. This background noise was evidently higher in degraded DNA isolated from formalin-fixed paraffin-embedded tissues as compared to high molecular weight DNA. A combination of AS-PCR, ddPCR and NGS revealed mosaic EGFR T790M allele in 2/68 (3%) NSCLC treated with the first-generation TKI. Both these tumors produced evident and durable response to gefitinib. CONCLUSION: Detection of mosaic EGFR T790M mutation in treatment-naïve samples may be compromised by yet unresolved technical issues and may have limited clinical value.

Weekly nab-paclitaxel in combination with carboplatin versus solvent-based paclitaxel plus carboplatin as first-line therapy in patients with advanced non-small-cell lung cancer: final results of a phase III trial.

PURPOSE: This phase III trial compared the efficacy and safety of albumin-bound paclitaxel (nab-paclitaxel) plus carboplatin with solvent-based paclitaxel (sb-paclitaxel) plus carboplatin in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: In all, 1,052 untreated patients with stage IIIB to IV NSCLC were randomly assigned 1:1 to receive 100 mg/m(2) nab-paclitaxel weekly and carboplatin at area under the concentration-time curve (AUC) 6 once every 3 weeks (nab-PC) or 200 mg/m(2) sb-paclitaxel plus carboplatin AUC 6 once every 3 weeks (sb-PC). The primary end point was objective overall response rate (ORR). RESULTS: On the basis of independent assessment, nab-PC demonstrated a significantly higher ORR than sb-PC (33% v 25%; response rate ratio, 1.313; 95% CI, 1.082 to 1.593; P = .005) and in patients with squamous histology (41% v 24%; response rate ratio, 1.680; 95% CI, 1.271 to 2.221; P < .001). nab-PC was as effective as sb-PC in patients with nonsquamous histology (ORR, 26% v 25%; P = .808). There was an approximately 10% improvement in progression-free survival (median, 6.3 v 5.8 months; hazard ratio [HR], 0.902; 95% CI, 0.767 to 1.060; P = .214) and overall survival (OS; median, 12.1 v 11.2 months; HR, 0.922; 95% CI, 0.797 to 1.066; P = .271) in the nab-PC arm versus the sb-PC arm, respectively. Patients ≥ 70 years old and those enrolled in North America showed a significantly increased OS with nab-PC versus sb-PC. Significantly less grade ≥ 3 neuropathy, neutropenia, arthralgia, and myalgia occurred in the nab-PC arm, and less thrombocytopenia and anemia occurred in the sb-PC arm. CONCLUSION: The administration of nab-PC as first-line therapy in patients with advanced NSCLC was efficacious and resulted in a significantly improved ORR versus sb-PC, achieving the primary end point. nab-PC produced less neuropathy than sb-PC.

Double-blind, placebo-controlled, randomized phase 2 study of the proapoptotic agent AT-101 plus docetaxel, in second-line non-small cell lung cancer.

BACKGROUND: AT-101 is an inhibitor of Bcl-2 family proteins including Bcl-2, Bcl-xL, Mcl-1, and Bcl-w. In vivo and in vitro studies have exhibited broad activity of AT-101, including synergy with docetaxel in non-small cell lung cancer tumor models. METHODS: We conducted a prospective, randomized (1:1), double-blind, placebo-controlled phase 2 study. Eligible patients must have received one prior chemotherapeutic regimen for advanced or metastatic non-small cell lung cancer and may also have received therapy with an epidermal growth factor receptor inhibitor. Patients received AT-101 (40 mg b.i.d. × 3 days) or placebo in combination with docetaxel (75 mg/m on day 1) every 21 days. The primary endpoint was progression-free survival (PFS) as determined by independent review; other endpoints include overall survival and PFS by investigator determination. Approximately 102 patients were planned to provide 70 events (80% power, hazard ratio [HR] of 0.6, one-sided alpha of 0.1). RESULTS: : One hundred six patients were assigned to treatment and 105 patients received at least one dose of AT-101 or placebo. Baseline factors were balanced between treatment groups: median age 59 years; 77% men, and 79% current or former smokers. Ninety-three percent of patients had distant metastatic disease at randomization and 56% squamous histology. The most frequently reported adverse events were fatigue (18%), anemia (18%), and dyspnea (18%). No statistically significant differences in serious adverse events were observed between AT-101 and placebo; grade 1/2 headaches appeared more frequently with AT-101 (9% versus 0%) and neutropenia was reported more frequently in the docetaxel plus placebo arm compared with docetaxel plus AT-101 (17% versus 8%). Unlike trials with continuous daily dosing of AT-101, no cases of small bowel obstruction were reported. The response rate and median PFS were not different between the arms by independent review, PFS 7.5 weeks for docetaxel plus AT-101 and 7.1 weeks for docetaxel plus placebo arms (HR, 1.04; p = 0.57). The median overall survival was 7.8 months for docetaxel plus AT-101 versus 5.9 months for docetaxel plus placebo (HR, 0.82; p = 0.21). CONCLUSIONS: The primary endpoint of improved PFS for AT-101 plus docetaxel was not met. AT-101 plus docetaxel was well tolerated with an adverse event profile indistinguishable from the base docetaxel regimen. AT-101 is the first oral, pan Bcl-2 family inhibitor to exhibit a possible survival benefit in a randomized study.

Phase III study of pemetrexed plus carboplatin compared with etoposide plus carboplatin in chemotherapy-naive patients with extensive-stage small-cell lung cancer.

PURPOSE: Following a phase II trial in which pemetrexed-platinum demonstrated similar activity to that of historical etoposide-platinum controls, a phase III study was conducted to compare pemetrexed-carboplatin with etoposide-carboplatin for the treatment of extensive-stage small-cell lung cancer (ES-SCLC). PATIENTS AND METHODS: Chemotherapy-naive patients with ES-SCLC and an Eastern Cooperative Oncology Group performance status of zero to 2 were randomly assigned to receive pemetrexed-carboplatin (pemetrexed 500 mg/m(2) on day 1; carboplatin at area under the serum concentration-time curve [AUC] 5 on day 1) or etoposide-carboplatin (etoposide 100 mg/m(2) on days 1 through 3; carboplatin AUC 5 on day 1) every 3 weeks for up to six cycles. The primary objective of the study was noninferiority of pemetrexed-carboplatin overall survival with a 15% margin. RESULTS: Accrual was terminated with 908 of 1,820 patients enrolled after results of a planned interim analysis. In the final analysis, pemetrexed-carboplatin was inferior to etoposide-carboplatin for overall survival (median, 8.1 v 10.6 months; hazard ratio [HR],1.56; 95% CI, 1.27 to 1.92; log-rank P < .01) and progression-free survival (median, 3.8 v 5.4 months; HR, 1.85; 95% CI, 1.58 to 2.17; log-rank P < .01). Objective response rates were also significantly lower for pemetrexed-carboplatin (31% v 52%; P < .001). Pemetrexed-carboplatin had lower grade 3 to 4 neutropenia, febrile neutropenia, and leukopenia than etoposide-carboplatin; grade 3 to 4 thrombocytopenia was comparable between arms and anemia was higher in the pemetrexed-carboplatin arm. CONCLUSION: Pemetrexed-carboplatin is inferior for the treatment of ES-SCLC. Planned translational research and pharmacogenomic analyses of tumor and blood samples may help explain the study results and provide insight into new treatment strategies.