Second- and third-line treatments in non-small cell lung cancer

A Small Molecule Targeting the Intracellular Tyrosine Kinase Domain of ROR1 (KAN0441571C) Induced Significant Apoptosis of Non-Small Cell Lung Cancer (NSCLC) Cells

The ROR1 receptor tyrosine kinase is expressed in embryonic tissues but is absent in normal adult tissues. ROR1 is of importance in oncogenesis and is overexpressed in several cancers, such as NSCLC. In this study, we evaluated ROR1 expression in NSCLC patients (N = 287) and the cytotoxic effects of a small molecule ROR1 inhibitor (KAN0441571C) in NSCLC cell lines. ROR1 expression in tumor cells was more frequent in non-squamous (87%) than in squamous (57%) carcinomas patients, while 21% of neuroendocrine tumors expressed ROR1 (p = 0.0001). A significantly higher proportion of p53 negative patients in the ROR1+ group than in the p53 positive non-squamous NSCLC patients (p = 0.03) was noted. KAN0441571C dephosphorylated ROR1 and induced apoptosis (Annexin V/PI) in a time- and dose-dependent manner in five ROR1+ NSCLC cell lines and was superior compared to erlotinib (EGFR inhibitor). Apoptosis was confirmed by the downregulation of MCL-1 and BCL-2, as well as PARP and caspase 3 cleavage. The non-canonical Wnt pathway was involved. The combination of KAN0441571C and erlotinib showed a synergistic apoptotic effect. KAN0441571C also inhibited proliferative (cell cycle analyses, colony formation assay) and migratory (scratch wound healing assay) functions. Targeting NSCLC cells by a combination of ROR1 and EGFR inhibitors may represent a novel promising approach for the treatment of NSCLC patients.

The Effect of the Kirsten Rat Sarcoma Viral Oncogene Homolog (Kras) Proto-Oncogene, GTPase Genetic Polymorphism on the Safety and Efficacy of Bevacizumab Combination Treatment Regimens for Patients with Nonsquamous, Non-Small Cell Lung Cancer with Brain Metastases

Background: Non-small cell lung cancer with brain metastasis (NSCLCBM) is normally observed in advanced-stage patients. Bevacizumab has shown to improve survival in the first-line treatment of metastatic brain NSCLC when added as a bolus plus irinotecan. However, a better understanding of the molecular mechanism is required to further drive progress in this field. Methods: A total of 155 patients were selected, including 42.10% with Kirsten rat sarcoma viral oncogene homolog (Kras)-mutant tumors. Of the 155 patients, 62.04% had developed brain metastasis (BM). Seven functional single-nucleotide polymorphisms (SNPs) in the Kras gene were extracted from the HapMap SNP database and were used for genotyping. The haplologit command in Statistical Software for Data Science (STATA) was used to model the association between haplotypes and case status. A Cox analysis was used to evaluate the prognostic value of the SNPs. Results: Among the patients treated with combination regimens, recurrence after local treatment was more frequent in those with two types of Kras mutations (odds ratio [OR] = 2.033 [0.5015-4.2552], p = 0.009). Among the patients with untreated BM, overall survival was shorter than that of patients with Kras mutations according to univariate analysis (OR = 5.130 [1.240-41.012], p = 0.033). Conclusions: Kras mutations have a predictive role for BM recurrence and outcome in patients with NSCLC treated with bevacizumab combination regimens.

A phase 1b study evaluating the safety and preliminary efficacy of berzosertib in combination with gemcitabine in patients with advanced non-small cell lung cancer

OBJECTIVES

Berzosertib (formerly M6620, VX-970) is an intravenous, highly potent and selective, first-in-class ataxia telangiectasia and Rad3-related (ATR) protein kinase inhibitor. We assessed the safety, tolerability, preliminary efficacy, and pharmacokinetics (PK) of berzosertib plus gemcitabine in an expansion cohort of patients with advanced non-small cell lung cancer (NSCLC). The association of efficacy with TP53 status and other tumor markers was also explored.

MATERIALS AND METHODS

Adult patients with advanced histologically confirmed NSCLC received berzosertib 210 mg/m2 (days 2 and 9) and gemcitabine 1000 mg/m2 (days 1 and 8) at the recommended phase 2 dose established in the dose escalation part of the study.

RESULTS

Thirty-eight patients received at least one dose of study treatment. The most common treatment-emergent adverse events were fatigue (55.3%), anemia (52.6%), and nausea (39.5%). Gemcitabine had no apparent effect on the PK of berzosertib. The objective response rate (ORR) was 10.5% (4/38, 90% confidence interval [CI]: 3.7-22.5%). In the exploratory analysis, the ORR was 30.0% (3/10, 90% CI: 9.0-61.0%) in patients with high loss of heterozygosity (LOH) and 11.0% (1/9, 90% CI: 1.0-43.0%) in patients with low LOH. The ORR was 33.0% (2/6, 90% CI: 6.0-73.0%) in patients with high tumor mutational burden (TMB), 12.5% (2/16, 90% CI: 2.0-34.0%) in patients with intermediate TMB, and 0% (0/3, 90% CI: 0.0-53.6%) in patients with low TMB.

CONCLUSIONS

Berzosertib plus gemcitabine was well tolerated in patients with advanced, pre-treated NSCLC. Based on the observed clinical efficacy, future clinical trials should involve genomically selected patients.

Migration and invasion of NSCLC suppressed by the downregulation of Src/focal adhesion kinase using single, double and tetra domain anti- CEACAM6 antibodies

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Overexpression of CEACAM 6 involved in the development of non-small cell lung cancer.

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Anti-CEACAM 6 antibodies with different valences can be used to target CEACAM 6 overexpressing tumor cells.

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Tetravalent sdAb (4Ab) showed significant effect on cell viability.

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High affinity anti-CEACAM 6 antibodies potentially inhibited migration via src/FAK pathway.

Carcinoembryonic antigen-related cell adhesion molecules 6 (CEACAM6) is a cell adhesion receptor. Expression of CEACAM6 in non-small cell lung cancer (NSCLC) associated with tumor progression and metastatic condition via Src/FAK signaling pathway. We established three anti-CEACAM6 antibodies with valences, which were designed to be monomeric sdAb, bivalent sdAb (2Ab), and tetravalent sdAb (4Ab). The anti-CEACAM6 antibodies can be used to target CEACAM6 overexpressing NSCLC. Anti-CEACAM6 antibodies, sdAb, 2Ab and 4Ab, were modified with different valency via protein engineering. sdAb and multivalent sdAbs (2Ab & 4Ab) were expressed and purified from E.coli and CHO cells, respectively. We compared the effect of anti-CEACAM6 antibodies with doxorubicin in NSCLC cell line both in vitro and in vivo. The 4Ab showed significant effect on cell viability. In addition, A549 cells treated with 2Ab and 4Ab inhibited the invasion and migration. In western blot, the 2Ab and 4Ab showed significant inhibition of phospho FAK domain Ty397 that is essential for activation of Src kinase family. Meanwhile, overall protein analysis revealed that 2Ab and 4Ab potently inhibited the phosphorylation of pSRC, pERK, pFAK, pAKT, MMP-2, MMP-9 and N-cadherin. Anti-tumor effect was observed in an A549 NSCLC xenograft model treated with 2Ab or 4Ab compared with doxorubicin. Confocal analysis showed higher targeting ability of 4Ab than that of 2Ab at 4 h incubation. Our data suggests that 2Ab and 4Ab inhibits EMT-mediated migration and invasion via suppression of Src/FAK signaling, which exhibits therapeutic efficiency for NSCLC treatment.

Is there still a role for mitomycin-based combination chemotherapy in treating patients with nonsmall cell lung cancer? A single institution experience

Background:

Mitomycin and irinotecan are widely used in the treatment of colorectal cancer, furthermore both of these drugs are active agents against nonsmall cell lung cancer and their combination has shown synergism in preclinical studies. The aim of the study was to evaluate the efficacy and safety of mitomycin- and irinotecan-based chemotherapy combination in patients with advanced nonsmall cell lung cancer progressing after previous antineoplastic therapies.

Methods:

Thirty-one consecutive patients suffering from nonsmall cell lung cancer, who underwent mitomycin- plus irinotecan-based chemotherapy as salvage treatment after failure of at least two previous systemic treatments, were retrospectively identified in our database. Between September 2003 and March 2011, 31 patients with histologically proven stage IIIB or IV nonsmall cell lung cancer, received mitomycin 5 mg/m2 on day 1 followed by irinotecan 150 mg/m2 on day 2. Cycles were repeated at 2-week interval.

Results:

A total of 164 cycles of treatment were given with a median of five per patient (range 1–10). The objective responses included partial response in 6 patients (19.3%), stable disease in 4 (13%), and progressive disease in 21 (67.7%). Median time to disease progression was 4 months, and median survival was 9+ months. Twelve patients (38%) reached 1-year survival. Grade 3–4 toxicities occurred in seven patients (22.5%), mainly myelosuppression (neutropenia, anemia, and thrombocytopenia), mucositis, and diarrhea. No treatment-related death was recorded.

Conclusion:

The mitomycin- and irinotecan-based combination chemotherapy seems to be tolerated and active in this subset of heavily pretreated patients with advanced nonsmall cell lung cancer. However, evaluation or recruitment of a larger number of patients would be needed to provide more adequate data on safety and activity of the described combination.

Engineering of self-assembled nanoparticle platform for precisely controlled combination drug therapy

The genomic revolution has identified therapeutic targets for a plethora of diseases, creating a need to develop robust technologies for combination drug therapy. In the present work, we describe a self-assembled polymeric nanoparticle (NP) platform to target and control precisely the codelivery of drugs with varying physicochemical properties to cancer cells. As proof of concept, we codelivered cisplatin and docetaxel (Dtxl) to prostate cancer cells with synergistic cytotoxicity. A polylactide (PLA) derivative with pendant hydroxyl groups was prepared and conjugated to a platinum(IV) [Pt(IV)] prodrug, c,t,c-[Pt(NH(3))(2)(O(2)CCH(2)CH(2)COOH)(OH)Cl(2)] [PLA-Pt(IV)]. A blend of PLA-Pt(IV) functionalized polymer and carboxyl-terminated poly(D,L-lactic-co-glycolic acid)-block-poly(ethylene glycol) copolymer in the presence or absence of Dtxl, was converted, in microfluidic channels, to NPs with a diameter of ∼100 nm. This process resulted in excellent encapsulation efficiency (EE) and high loading of both hydrophilic platinum prodrug and hydrophobic Dtxl with reproducible EEs and loadings. The surface of the NPs was derivatized with the A10 aptamer, which binds to the prostate-specific membrane antigen (PSMA) on prostate cancer cells. These NPs undergo controlled release of both drugs over a period of 48-72 h. Targeted NPs were internalized by the PSMA-expressing LNCaP cells via endocytosis, and formation of cisplatin 1,2-d(GpG) intrastrand cross-links on nuclear DNA was verified. In vitro toxicities demonstrated superiority of the targeted dual-drug combination NPs over NPs with single drug or nontargeted NPs. This work reveals the potential of a single, programmable nanoparticle to blend and deliver a combination of drugs for cancer treatment.

Clinical predictive factors for advanced non-small cell lung cancer (NSCLC) patients receiving third-line therapy: Selecting the unselectable?

A not negligible proportion of NSCLC patients may be considered eligible for a third-line therapy with a palliative intent. Unfortunately, it is not uncommon to observe toxic side-effects with lack of efficacy. Aim of our study was to analyse clinical factors potentially influencing the global outcome of advanced NSCLC patients receiving third-line therapy. Patients with histologically proven inoperable (IIIB) or metastatic (IV) NSCLC, who received a second- and third-line treatment (either with EGFR-TKIs or chemotherapy), were eligible for our analysis. 143 patients received a second-line treatment after failing a first line cisplatin-based chemotherapy. 52 patients from this series were offered a third-line treatment. In the third-line setting, a better overall survival (months) was related to sex and to response to second-line. Globally, our findings seem to indicate that an improved overall survival in third-line is more strictly dependent on response to second-line, thus suggesting that when planning a third-line treatment, response to second-line should be considered as a relevant factor for the decision making process.

Pharmacogenetic pathway analysis of irinotecan

Irinotecan, a chemotherapeutic agent against various solid tumors, is a prodrug requiring activation to SN-38. Irinotecan's complex pharmacokinetics potentially allow for many genetic sources of variability. We explored relationships between pharmacokinetic pathways and polymorphisms in genes associated with irinotecan's metabolism and transport. We fitted a seven-compartment pharmacokinetic model with enterohepatic recirculation (EHR) to concentrations of irinotecan and metabolites SN-38, SN-38 glucuronide (SN-38G), and aminopentanoic acid (APC). Principal component analysis (PCA) of patient-specific parameter estimates produced measures interpretable along pathways. Nine principal components provided good characterization of the overall variation. Polymorphisms in genes UGT1A1, UGT1A7, and UGT1A9 had strong associations with a component corresponding to the irinotecan-to-SN-38 pathway and SN-38 recirculation and to a component relating to SN-38-to-SN-38G conversion and elimination of SN-38G. The component characterizing irinotecan's compartments was associated with HNF1alpha and ABCC2 polymorphisms. The exploratory analysis with PCA in this pharmacogenetic analysis was able to identify known associations and may have allowed identification of previously uncharacterized functional polymorphisms.

Combination phenylbutyrate/gemcitabine therapy effectively inhibits in vitro and in vivo growth of NSCLC by intrinsic apoptotic pathways

Background

Standard chemotherapy protocols in NSCLC are of limited clinical benefit. Histone deacetylase (HDAC) inhibitors represent a new strategy in human cancer therapy. In this study the combination of the HDAC inhibitor phenylbutyrate (PB) and the nucleoside analogue gemcitabine (GEM) was evaluated and the mechanisms underlying increased cell death were analyzed.

Methods

Dose escalation studies evaluating the cytotoxicity of PB (0.01–100 mM), GEM (0.01–100 μg/ml) and a combination of the two were performed on two NSCLC cell lines (BEN and KNS62). Apoptotic cell death was quantified. The involvement of caspase-dependent cell death and MAP-kinase activation was analyzed. Additionally, mitochondrial damage was determined. In an orthotopic animal model the combined effect of PB and GEM on therapy was analyzed.

Results

Applied as a single drug both GEM and PB revealed limited potential to induce apoptosis in KNS62 and Ben cells. Combination therapy was 50–80% (p = 0.012) more effective than either agent alone. On the caspase level, combination therapy significantly increased cleavage of the pro-forms compared to single chemotherapy. The broad spectrum caspase-inhibitor zVAD was able to inhibit caspase cleavage completely, but reduced the frequency of apoptotic cells only by 30%. Combination therapy significantly increased changes in MTP and the release of cyto-c, AIF and Smac/Diabolo into the cytoplasm. Furthermore, the inhibitors of apoptosis c-IAP1 and c-IAP2 were downregulated and it was shown that in combination therapy JNK activation contributed significantly to induction of apoptosis. The size of the primary tumors growing orthotopically in SCID mice treated for 4 weeks with GEM and PB was significantly reduced (2.2–2.7 fold) compared to GEM therapy alone. The Ki-67 (KNS62: p = 0.015; Ben: p = 0.093) and topoisomerase IIα (KNS62: p = 0.008; Ben: p = 0.064) proliferation indices were clearly reduced in tumors treated by combination therapy, whereas the apoptotic index was comparably low in all groups.

Conclusion

Therapy combining GEM and the HDAC inhibitor PB initiates a spectrum of apoptosis-inducing mitochondrial and further JNK-dependent events, thereby overcoming the therapeutic resistance of NSCLC tumor cells. In vivo, the combination therapy substantially reduced tumor cell proliferation, suggesting that the well tolerated PB is a useful supplemental therapeutic agent in NSCLC.

Defective Mre11-dependent activation of Chk2 by ataxia telangiectasia mutated in colorectal carcinoma cells in response to replication-dependent DNA double strand breaks

The Mre11.Rad50.Nbs1 (MRN) complex binds DNA double strand breaks to repair DNA and activate checkpoints. We report MRN deficiency in three of seven colon carcinoma cell lines of the NCI Anticancer Drug Screen. To study the involvement of MRN in replication-mediated DNA double strand breaks, we examined checkpoint responses to camptothecin, which induces replication-mediated DNA double strand breaks after replication forks collide with topoisomerase I cleavage complexes. MRN-deficient cells were deficient for Chk2 activation, whereas Chk1 activation was independent of MRN. Chk2 activation was ataxia telangiectasia mutated (ATM)-dependent and associated with phosphorylation of Mre11 and Nbs1. Mre11 complementation in MRN-deficient HCT116 cells restored Chk2 activation as well as Rad50 and Nbs1 levels. Conversely, Mre11 down-regulation by small interference RNA (siRNA) in HT29 cells inhibited Chk2 activation and down-regulated Nbs1 and Rad50. Proteasome inhibition also restored Rad50 and Nbs1 levels in HCT116 cells suggesting that Mre11 stabilizes Rad50 and Nbs1. Chk2 activation was also defective in three of four MRN-proficient colorectal cell lines because of low Chk2 levels. Thus, six of seven colon carcinoma cell lines from the NCI Anticancer Drug Screen are functionally Chk2-deficient in response to replication-mediated DNA double strand breaks. We propose that Mre11 stabilizes Nbs1 and Rad50 and that MRN activates Chk2 downstream from ATM in response to replication-mediated DNA double strand breaks. Chk2 deficiency in HCT116 is associated with defective S-phase checkpoint, prolonged G2 arrest, and hypersensitivity to camptothecin. The high frequency of MRN and Chk2 deficiencies may contribute to genomic instability and therapeutic response to camptothecins in colorectal cancers.