Association of PD-L1 overexpression with activating EGFR mutations in surgically resected nonsmall-cell lung cancer

BACKGROUND

Recent clinical trials have shown that immune-checkpoint blockade yields a clinical response in a subset of individuals with advanced nonsmall-cell lung cancer (NSCLC). We examined whether the expression of programmed death-ligand 1 (PD-L1) is related to clinicopathologic or prognostic factors in patients with surgically resected NSCLC.

PATIENTS AND METHODS

The expression of PD-L1 was evaluated by immunohistochemical analysis in 164 specimens of surgically resected NSCLC. Cell surface expression of PD-L1 in NSCLC cell lines was quantified by flow cytometry.

RESULTS

Expression of PD-L1 in tumor specimens was significantly higher for women than for men, for never smokers than for smokers, and for patients with adenocarcinoma than for those with squamous cell carcinoma. Multivariate analysis revealed that the presence of epidermal growth factor receptor gene (EGFR) mutations and adenocarcinoma histology were significantly associated with increased PD-L1 expression in a manner independent of other factors. Cell surface expression of PD-L1 was also significantly higher in NSCLC cell lines positive for activating EGFR mutations than in those with wild-type EGFR. The EGFR inhibitor erlotinib downregulated PD-L1 expression in the former cell lines but not in the latter, suggesting that PD-L1 expression is increased by EGFR signaling conferred by activating EGFR mutations. A high level of PD-L1 expression in resected tumor tissue was associated with a significantly shorter overall survival for NSCLC patients.

CONCLUSIONS

High expression of PD-L1 was associated with the presence of EGFR mutations in surgically resected NSCLC and was an independent negative prognostic factor for this disease.

Proteolytic release of CD44 intracellular domain and its role in the CD44 signaling pathway

CD44 is a widely distributed cell surface adhesion molecule and is implicated in diverse biological processes. However, the nature of intracellular signaling triggered by CD44 remains to be elucidated. Here, we show that CD44 undergoes sequential proteolytic cleavage in the ectodomain and intracellular domain, resulting in the release of a CD44 intracellular domain (ICD) fragment. Consequently, CD44ICD acts as a signal transduction molecule, where it translocates to the nucleus and activates transcription mediated through the 12-O-tetradecanoylphorbol 13-acetate-responsive element, which is found in numerous genes involved in diverse cellular processes. Expression of an uncleavable CD44 mutant as well as metalloprotease inhibitor treatment blocks CD44-mediated transcriptional activation. In search of the underlying mechanism, we have found that CD44ICD potentiates transactivation mediated by the transcriptional coactivator CBP/p300. Furthermore, we show that cells expressing CD44ICD produce high levels of CD44 messenger RNA, suggesting that the CD44 gene is one of the potential targets for transcriptional activation by CD44ICD. These observations establish a novel CD44 signaling pathway and shed new light on the functional link between proteolytic processing of an adhesion molecule at the cell surface and transcriptional activation in the nucleus.

CD44 cleavage induced by a membrane-associated metalloprotease plays a critical role in tumor cell migration

CD44 is a cell surface receptor for hyaluronate, a component of the extracellular matrix (ECM). Although CD44 has been implicated in tumor invasion and metastasis, the molecular mechanisms remain to be elucidated. Here we find that CD44 expressed in cancer cells is cleaved at the membrane-proximal region of the ectodomain and the membrane-bound cleavage product can be detected using an antibody against the cytoplasmic domain of CD44. Furthermore, we report that CD44 cleavage is mediated by a membrane-associated metalloprotease expressed in cancer cells. A tissue inhibitor of metalloproteases-1 (TIMP-1), as well as metalloprotease inhibitors, inhibit CD44 cleavage in the cell-free assay. Contrary, serine protease inhibitors enhance CD44 cleavage, and the enhancement can be prevented by pretreatment with a metalloprotease inhibitor. Thus, CD44 cleavage is regulated by an intricate balance between some proteases and their inhibitors. Interestingly, treatment with the metalloprotease blocker 1,10-phenanthroline, which strongly prevent the CD44 cleavage, suppressed RERF-LC-OK lung cancer cell migration on a hyaluronate substrate, but not on several other substrates. These results suggest that CD44 cleavage plays a critical role in an efficient cell-detachment from a hyaluronate substrate during the cell migration and consequently promotes CD44-mediated cancer cell migration. Our present data indicate that CD44, not only ECM per se, is one of the targets of pericellular proteolysis involved in tumor invasion and metastasis.

Multicentre prospective phase II trial of gefitinib for advanced non-small cell lung cancer with epidermal growth factor receptor mutations: results of the West Japan Thoracic Oncology Group trial (WJTOG0403)

The purpose of this study was to evaluate the efficacy of gefitinib and the feasibility of screening for epidermal growth factor receptor (EGFR) mutations among select patients with advanced non-small cell lung cancer (NSCLC). Stage IIIB/IV NSCLC, chemotherapy-naive patients or patients with recurrences after up to two prior chemotherapy regimens were eligible. Direct sequencing using DNA from tumour specimens was performed by a central laboratory to detect EGFR mutations. Patients harbouring EGFR mutations received gefitinib. The primary study objective was response; the secondary objectives were toxicity, overall survival (OS), progression-free survival (PFS), 1-year survival (1Y-S) and the disease control rate (DCR). Between March 2005 and January 2006, 118 patients were recruited from 15 institutions and were screened for EGFR mutations, which were detected in 32 patients – 28 of whom were enrolled in the present study. The overall response rate was 75%, the DCR was 96% and the median PFS was 11.5 months. The median OS has not yet been reached, and the 1Y-S was 79%. Thus, gefitinib chemotherapy in patients with advanced NSCLC harbouring EGFR mutations was highly effective. This trial documents the feasibility of performing a multicentre phase II study using a central typing laboratory, demonstrating the benefit to patients of selecting gefitinib treatment based on their EGFR mutation status.

Mutations in the LKB1 tumour suppressor are frequently detected in tumours from Caucasian but not Asian lung cancer patients

Somatic mutations of LKB1 tumour suppressor gene have been detected in human cancers including non-small cell lung cancer (NSCLC). The relationship between LKB1 mutations and clinicopathological characteristics and other common oncogene mutations in NSCLC is inadequately described. In this study we evaluated tumour specimens from 310 patients with NSCLC including those with adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma histologies. Tumours were obtained from patients of US (n=143) and Korean (n=167) origin and screened for LKB1, KRAS, BRAF, and EGFR mutations using RT—PCR-based SURVEYOR-WAVE method followed by Sanger sequencing. We detected mutations in the LKB1 gene in 34 tumours (11%). LKB1 mutation frequency was higher in NSCLC tumours of US origin (17%) compared with 5% in NSCLCs of Korean origin (P=0.001). They tended to occur more commonly in adenocarcinomas (13%) than in squamous cell carcinomas (5%) (P=0.066). LKB1 mutations associated with smoking history (P=0.007) and KRAS mutations (P=0.042) were almost mutually exclusive with EGFR mutations (P=0.002). The outcome of stages I and II NSCLC patients treated with surgery alone did not significantly differ based on LKB1 mutation status. Our study provides clinical and molecular characteristics of NSCLC, which harbour LKB1 mutations.

Calcium influx triggers the sequential proteolysis of extracellular and cytoplasmic domains of E-cadherin, leading to loss of beta-catenin from cell-cell contacts

Cadherins are major cell-cell adhesion molecules in both tumor and normal tissues. Although serum levels of soluble E-cadherin have been shown to be higher in the cancer patients than in healthy volunteers, the detail mechanism regulating release of soluble E-cadherin remains to be elucidated. Here we show that the ectodomain of E-cadherin is proteolytically cleaved from some cancer cells by a membrane-bound metalloprotease to yield soluble form, and the residual membrane-tethered cleavage product is subsequently degraded by intracellular proteolytic pathway. Futhermore, we show that extracellular calcium influx, that is induced by mechanical scraping of cells or ionomycin treatment, enhances the metalloprotease-mediated E-cadherin cleavage and the subsequent degradation of the cytoplasmic domain. Immunocytochemical analysis demonstrates that the sequential proteolysis of E-cadherin triggered by the calcium influx results in translocation of beta-catenin from the cell-cell contacts to cytoplasm. Our data suggest that calcium influx-induced proteolysis of E-cadherin not only disrupts the cell-cell adhesion but also activates beta-catenin-mediated intracellular signaling pathway, potentially leading to alterations in motility and proliferation activity of cells.

Expression of Bcl-2 family members in human melanocytes, in melanoma metastases and in melanoma cell lines

In human melanoma no complete information about the expression of the apoptosis-promoting and apoptosis-inhibiting members of the Bcl-2 family has been available to date. In this study we have investigated by Western blotting the expression pattern of Bcl-2 and its homologues Bax, Bak, Bcl-xL, Bcl-xS, Mcl-1 and Bad in 12 distant lymph node metastases from patients who have been treated by different regimes, in nine newly established cell lines of these metastases, in three cell lines obtained from other sources and in primary melanocytic cell lines from three neonatal and two adult subjects. Taken together, our data suggest that Bax, Bak, Bad, Bcl-xL and Mcl-1 are expressed in addition to Bcl-2 in both normal melanocytes and in cell lines established from melanoma metastases. Regarding the role of Bcl-2 and its homologues, our data suggest that expression of this class of proteins is widespread and qualitatively similar in melanoma cell lines and normal human melanocytes. Although the expression of these proteins might affect growth behaviour and the progression of melanomas, our results are not compatible with the hypothesis that the Bcl-2 homologues investigated play a dominant role in the process of malignant transformation of melanocytes.

Differential roles of trans-phosphorylated EGFR, HER2, HER3, and RET as heterodimerisation partners of MET in lung cancer with MET amplification

Background:

MET is a receptor tyrosine kinase (RTK) whose gene is amplified in various tumour types. We investigated the roles and mechanisms of RTK heterodimerisation in lung cancer with MET amplification.

Methods:

With the use of an RTK array, we identified phosphorylated RTKs in lung cancer cells with MET amplification. We examined the roles and mechanisms of action of these RTKs with immunoprecipitation, annexin V binding, and cell migration assays.

Results:

We identified epidermal growth factor receptor (EGFR), human EGFR (HER)2, HER3, and RET in addition to MET as highly phosphorylated RTKs in lung cancer cells with MET amplification. Immunoprecipitation revealed that EGFR, HER2, HER3, and RET each formed a heterodimer exclusively with MET and that these associations were markedly reduced in extent by treatment with a MET kinase inhibitor. RNA interference-mediated depletion of EGFR, HER2, or HER3 induced apoptosis in association with inhibition of AKT and ERK signalling pathways, whereas depletion of HER2 or RET inhibited both cell migration and STAT3 signalling.

Conclusion:

Our data suggest that heterodimers of MET with EGFR, HER2, HER3, or RET have differential roles in tumour development, and they provide new insight into the function of trans-phosphorylated RTKs as heterodimerisation partners of MET in lung cancer with MET amplification.

Safety and efficacy of weekly nab®-paclitaxel in combination with carboplatin as first-line therapy in elderly patients with advanced non-small-cell lung cancer

BACKGROUND

This analysis evaluates safety and efficacy in elderly (≥ 70 years old) versus younger patients enrolled in a phase III advanced non-small-cell lung cancer (NSCLC) trial.

PATIENTS AND METHODS

Untreated stage IIIB/IV patients with PS 0/1 were randomly assigned (1:1) to carboplatin AUC6, day 1 every 3 weeks, and either nab-paclitaxel (Abraxane) 100 mg/m(2) weekly (nab-P/C) or solvent-based paclitaxel (Taxol) 200 mg/m(2) day 1 every 3 weeks (sb-P/C). The primary end-point was overall response rate (ORR).

RESULTS

Fifteen percent of 1052 enrolled patients were elderly: nab-P/C, n = 74; sb-P/C, n = 82. In both age cohorts, the ORR was higher with nab-P/C versus sb-P/C (age ≥ 70: 34% versus 24%, P = 0.196; age <70: 32% versus 25%, P = 0.013). In elderly patients, progression-free survival (PFS) trended in favor of nab-P/C (median 8.0 versus 6.8 months, hazard ratio (HR) 0.687, P = 0.134), and overall survival (OS) was significantly improved (median 19.9 versus 10.4 months, HR 0.583, P = 0.009). In younger patients, PFS (median 6.0 versus 5.8 months, HR 0.903, P = 0.256) and OS (median 11.4 versus 11.3 months, HR 0.999, P = 0.988) were similar in both arms. Adverse events were similar in both age groups, with less neutropenia (P = 0.015), neuropathy (P = 0.001), and arthralgia (P = 0.029), and increased anemia (P = 0.007) with nab-P/C versus sb-P/C.

CONCLUSIONS

In elderly NSCLC patients, nab-P/C as first-line therapy was well tolerated and improved the ORR and PFS, with substantially longer OS versus sb-PC.

Integrated kinetics of X chromosome inactivation in differentiating embryonic stem cells

Inactivation of the X chromosome during early female development and the subsequent maintenance of this transcriptionally inert state through countless cell divisions remain a paradigm for epigenetic regulation in mammals. Nevertheless, the exact mechanisms underlying this chromosome-wide silencing process remain unclear. Using differentiating female embryonic stem (ES) cells as a model system, we recently found that histone H3 tail modifications are among the earliest known chromatin changes in the X inactivation process, appearing as soon as Xist RNA accumulates on the X chromosome, but prior to transcriptional silencing of X-linked genes (Heard et al., 2001). In this report we present an integrated analysis of the sequence of early events and chromatin modifications underlying X inactivation in differentiating female ES cells. We have extended our previous analysis concerning changes in histone tail modification states. We find that the hypomethylation of Arg-17 and that of Lys-36 on histone H3 also characterize the inactive X chromosome, and that these profiles show a similarly early onset during the initiation of X inactivation. In addition, we have investigated the kinetics of the shift in replication timing of the X chromosome undergoing inactivation. This event occurs slightly later than Xist RNA coating and the chromatin modifications. Finally, from an early stage in the X inactivation process, characteristic histone modification patterns can be found on the X chromosome at mitosis, suggesting that they represent true epigenetic marks of the inactive state.

Enhancement of the antitumor activity of ionising radiation by nimotuzumab, a humanised monoclonal antibody to the epidermal growth factor receptor, in non-small cell lung cancer cell lines of differing epidermal growth factor receptor status

The expression and activity of the epidermal growth factor receptor (EGFR) are determinants of radiosensitivity in several tumour types, including non-small cell lung cancer (NSCLC). However, little is known of whether genetic alterations of EGFR in NSCLC cells affect the therapeutic response to monoclonal antibodies (mAbs) to EGFR in combination with radiation. We examined the effects of nimotuzumab, a humanised mAb to EGFR, in combination with ionising radiation on human NSCLC cell lines of differing EGFR status. Flow cytometry revealed that H292 and Ma-1 cells expressed high and moderate levels of EGFR on the cell surface, respectively, whereas H460, H1299, and H1975 cells showed a low level of surface EGFR expression. Immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in H292 and Ma-1 cells but not in H460, H1299, or H1975 cells. Nimotuzumab augmented the cytotoxic effect of radiation in H292 and Ma-1 cells in a clonogenic assay in vitro, with a dose enhancement factor of 1.5 and 1.3, respectively. It also enhanced the antitumor effect of radiation on H292 and Ma-1 cell xenografts in nude mice, with an enhancement factor of 1.3 and 4.0, respectively. Nimotuzumab did not affect the radioresponse of H460 cells in vitro or in vivo. Nimotuzumab enhanced the antitumor efficacy of radiation in certain human NSCLC cell lines in vitro and in vivo. This effect may be related to the level of EGFR expression on the cell surface rather than to EGFR mutation.

Activin A inhibits vascular endothelial cell growth and suppresses tumour angiogenesis in gastric cancer

Background:

Activin A is a multi-functional cytokine belonging to the transforming growth factor-β (TGF-β) superfamily; however, the effect of activin A on angiogenesis remains largely unclear. We found that inhibin β A subunit (INHBA) mRNA is overexpressed in gastric cancer (GC) specimens and investigated the effect of activin A, a homodimer of INHBA, on angiogenesis in GC.

Methods:

Anti-angiogenic effects of activin A via p21 induction were evaluated using human umbilical vein endothelial cells (HUVECs) in vitro and a stable INHBA-introduced GC cell line in vivo.

Results:

Compared with TGF-β, activin A potently inhibited the cellular proliferation and tube formation of HUVECs with induction of p21. A promoter assay and a chromatin immunoprecipitation assay revealed that activin A directly regulates p21 transcriptional activity through Smads. Stable p21-knockdown significantly enhanced the cellular proliferation of HUVECs. Notably, stable p21-knockdown exhibited a resistance to activin-mediated growth inhibition in HUVECs, indicating that p21 induction has a key role on activin A-mediated growth inhibition in vascular endothelial cells. Finally, a stable INHBA-introduced GC cell line exhibited a decrease in tumour growth and angiogenesis in vivo.

Conclusion:

Our findings highlight the suppressive role of activin A, unlike TGF-β, on tumour growth and angiogenesis in GC.

Anti-HER3 monoclonal antibody patritumab sensitizes refractory non-small cell lung cancer to the epidermal growth factor receptor inhibitor erlotinib

Human epidermal growth factor receptor (HER) 3 is aberrantly overexpressed and correlates with poor prognosis in non-small cell lung cancer (NSCLC). Patritumab is a monoclonal antibody against HER3 that has shown promising results in early-phase clinical trials, but an optimal target population for the drug has yet to be identified. In the present study, we examined whether heregulin, a HER3 ligand that is also overexpressed in a subset of NSCLC, can be used as a biomarker to predict the antitumorigenic efficacy of patritumab and whether the drug can overcome the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) resistance induced by heregulin. Patritumab sensitivity was associated with heregulin expression, which, when abolished, resulted in the loss of HER3 and AKT activation and growth arrest. Furthermore, heregulin overexpression induced EGFR TKI resistance in NSCLC cells harbouring an activating EGFR mutation, while HER3 and AKT activation was maintained in the presence of erlotinib in heregulin-overexpressing, EGFR-mutant NSCLC cells. Sustained HER3-AKT activation was blocked by combining erlotinib with either anti-HER2 or anti-HER3 antibody. Notably, heregulin was upregulated in tissue samples from an NSCLC patient who had an activating EGFR mutation but was resistant to the TKI gefitinib. These results indicate that patritumab can overcome heregulin-dependent EGFR inhibitor resistance in NSCLC in vitro and in vivo and suggest that it can be used in combination with EGFR TKIs to treat a subset of heregulin-overexpressing NSCLC patients.

Regulated CD44 cleavage under the control of protein kinase C, calcium influx, and the Rho family of small G proteins

CD44 is a cell surface receptor for several extracellular matrix components and is implicated in tumor cell invasion and metastasis. Our previous studies have shown that CD44 expressed in cancer cells is proteolytically cleaved at the extracellular domain through membrane-associated metalloproteases and that CD44 cleavage plays a critical role in CD44-mediated tumor cell migration (Okamoto, I., Kawano, Y., Tsuiki, H., Sasaki, J., Nakao, M., Matsumoto, M., Suga, M., Ando, M., Nakajima, M., and Saya, H. (1999) Oncogene 18, 1435-1446). In the present study, we first demonstrate rapid degradation of the membrane-tethered CD44 cleavage product through intracellular proteolytic pathways, and it occurs only after CD44 extracellular cleavage. To address the mechanisms regulating CD44 cleavage at the extracellular domain, we show that 12-O-tetradecanoylphorbol 13-acetate (TPA) and the calcium ionophore ionomycin rapidly enhance metalloprotease-mediated CD44 cleavage in U251MG cells via protein kinase C-dependent and -independent pathways, respectively, suggesting the existence of multiple distinct pathways for regulation of CD44 cleavage. Concomitant with TPA-induced CD44 cleavage, TPA treatment induces redistribution of CD44 and ERM proteins (ezrin, radixin, and moesin) to newly generated membrane ruffling areas. Treatment with lysophosphatidic acid, which is known to activate the Rho-dependent pathway, inhibits TPA-induced CD44 redistribution and CD44 cleavage. Furthermore, overexpression of Rac dominant active mutants results in the redistribution of CD44 to the Rac-induced ruffling areas and the enhancement of CD44 cleavage. These results suggest that the Rho family proteins play a role in regulation of CD44 distribution and cleavage.

Evaluating the role of inducible nitric oxide synthase using a novel and selective inducible nitric oxide synthase inhibitor in septic lung injury produced by cecal ligation and puncture

We studied the role of inducible nitric oxide synthase (iNOS) in septic lung injury using a novel and selective iNOS inhibitor (a fused piperidine derivative; ONO-1714) following a cecal ligation and puncture (CLP) procedure. All rats that received CLP died within 48 h after the intervention. The subcutaneous injection of ONO-1714 at 0.03 mg/kg every 12 h resulted in a significantly longer survival time than the saline control only when administration was started 12 h after the CLP procedure. The other administration schedules, which started immediately or 6 h after the intervention, did not show any improvement in the survival rates in comparison with the saline control. The administration of ONO-1714 at higher (0.1 mg/ kg) or lower (0.01 mg/kg) doses when given anytime after the intervention did not improve the survival rates. The NO(x) (NO(2)(-) + NO(3)(-)) levels in the plasma significantly increased 12 h after intervention in comparison with NO(x) at 0 h and thereafter further increased in parallel with the time elapsed. The CLP rats that were initially treated with ONO-1714 (0.03 mg/kg subcutaneously every 12 h) 12 h after intervention showed significantly reduced NO(x) levels in the plasma in comparison with the saline control. The NO synthase activity in lung homogenates increased from 6 to 24 h after the CLP and thereafter decreased to 42 h. The administration of ONO-1714 inhibited iNOS activity (under calcium-free conditions) in preference to total iNOS activity (under calcium-dependent conditions) in lung homogenates, which thus suggested that this compound selectively inhibited iNOS in lung tissue. The iNOS protein expression in the lung and liver homogenates showed a similar time course with alterations of NOS activity, namely a maximum level at 24 h after the intervention followed by decreasing levels to 42 h. On the other hand, other isozymes of NOS, eNOS, and nNOS in lung homogenates, were constantly expressed over the time course after the CLP. Since the iNOS mRNA expression in lung homogenates continued to elevate until 42 h, the decrease in iNOS activity and protein expression later than 24 h after the CLP was thus considered to be due to some posttranscriptional mechanism during the late phase of sepsis. In conclusion, intervention with a potent and selective iNOS inhibitor seemed to improve survival in CLP rats when used at the appropriate doses and time points. However, the self-limited mechanism of iNOS regulation in the lungs may also indicate that iNOS plays only a limited role in sepsis and septic shock.

Final overall survival results of WJTOG3405, a randomized phase III trial comparing gefitinib versus cisplatin with docetaxel as the first-line treatment for patients with stage IIIB/IV or postoperative recurrent EGFR mutation-positive non-small-cell lung cancer

BACKGROUND

Primary analysis of the phase III study WJTOG 3405 demonstrated superiority of progression-free survival (PFS) for gefitinib (G) in patients treated with the epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) gefitinib compared with cisplatin plus docetaxel (CD) as the first-line treatment of stage IIIB/IV or postoperative recurrent EGFR mutation-positive non-small-cell lung cancer. This report presents final overall survival (OS) data.

PATIENTS AND METHODS

Patients were randomized between G (250 mg/day orally) and cisplatin (80 mg/m2 intravenously) plus docetaxel (60 mg/m2 i.v.), administered every 21 days for three to six cycles. After the exclusion of 5 patients, 172 patients (86 in each group, modified intention-to-treat population) were included in the survival analysis. OS was re-evaluated using updated data (data cutoff, 30 September 2013; median follow-up time 59.1 months). The Kaplan-Meier method and the log-rank test were used for analysis, and hazard ratios (HRs) for death were calculated using the Cox proportional hazards model.

RESULTS

OS events in the G group and CD group were 68 (79.1%) out of 86 and 59 (68.6%) out of 86, respectively. Median survival time for G and CD were 34.9 and 37.3 months, respectively, with an HR of 1.252 [95% confidence interval (CI): 0.883-1.775, P = 0.2070]. Multivariate analysis identified postoperative recurrence and stage IIIB/IV disease as independent prognostic factors, with an HR of 0.459 (95% CI: 0.312-0.673, P < 0.001). Median survival time (postoperative recurrence versus stage IIIB/IV disease) were 44.5 and 27.5 months in the G group and 45.5 and 32.8 months in the CD group, respectively.

CONCLUSION

G did not show OS benefits over CD as the first-line treatment. OS of patients with postoperative recurrence was better than that of stage IIIB/IV disease, even though both groups had metastatic disease.This study was registered with UMIN (University Hospital Medical Information Network in Japan), number 000000539.

Erlotinib plus bevacizumab vs erlotinib monotherapy as first-line treatment for advanced EGFR mutation-positive non-squamous non-small-cell lung cancer: Survival follow-up results of the randomized JO25567 study

OBJECTIVES

The JO25567 randomized Phase II study demonstrated a statistically significant progression-free survival (PFS) benefit with erlotinib plus bevacizumab compared with erlotinib monotherapy in chemotherapy-naïve Japanese patients with epidermal growth factor receptor mutation-positive (EGFR+) non-small-cell lung cancer (NSCLC). Here we present updated PFS and final overall survival (OS) data after a median follow-up of 34.7 months.

MATERIALS AND METHODS

Patients with stage IIIB/IV or postoperative recurrent NSCLC were randomized to receive oral erlotinib 150 mg once daily (n = 77) or erlotinib in combination with intravenous bevacizumab 15 mg/kg every 21 days (n = 75) until disease progression or unacceptable toxicity. OS was analyzed using an unstratified Cox proportional hazards model.

RESULTS

Consistent with the primary analysis, addition of bevacizumab to erlotinib was associated with a significant improvement in PFS (hazard ratio [HR] 0.52; 95 % confidence interval [CI]: 0.35-0.76; log-rank two-sided P = 0.0005; median 16.4 months vs 9.8 months, respectively). In contrast, a significant improvement in OS was not seen (HR 0.81; 95 % CI, 0.53-1.23; P =  0.3267; median 47.0 months vs 47.4 months, respectively). Post-study therapy was similar between the treatment arms and EGFR mutation type did not affect OS outcomes. The 5-year OS rate was numerically higher with erlotinib plus bevacizumab vs erlotinib monotherapy (41 % vs 35 %). Updated safety analyses confirmed the previously reported manageable tolerability profile, with no new safety issues.

CONCLUSION

Addition of bevacizumab to first-line erlotinib did not show significant improvement in OS in Japanese patients with stage IIIB/IV or postoperative recurrent EGFR+ NSCLC. Both treatment arms showed a similar median OS benefit (as long as 4 years), irrespective of individual patient characteristics. Results from ongoing studies evaluating the combination of EGFR and VEGF signaling inhibitors are eagerly awaited.

TRIAL REGISTRATION

JapicCTI-111390 and JapicCTI-142569.

Safety and efficacy analysis by histology of weekly nab-paclitaxel in combination with carboplatin as first-line therapy in patients with advanced non-small-cell lung cancer

BACKGROUND

This analysis compared the efficacy and safety outcomes by histology of nab-paclitaxel (nab-P) plus carboplatin (C) versus solvent-based paclitaxel (sb-P) plus C in patients with advanced non-small-cell lung cancer (NSCLC) based on preplanned stratification factors specified in the phase III trial protocol.

PATIENTS AND METHODS

Patients with untreated stage III/IV NSCLC received 100 mg/m(2) nab-P weekly and C (area under the curve, AUC = 6) every 3 weeks (q3w) or 200 mg/m(2) sb-P plus C (AUC = 6) q3w. Primary end point was objective overall response rate (ORR).

RESULTS

nab-P/C versus sb-P/C produced a significantly higher ORR (41% versus 24%; response rate ratio [RRR] 1.680; P < 0.001) in patients with squamous cell (SCC) NSCLC. For nab-P/C versus sb-P/C, ORRs were 26% versus 27% (RRR 0.966; P = 0.814) in patients with adenocarcinoma, 33% versus 15% (RRR 2.167; P = 0.323) in patients with large cell carcinoma (LC), and 24% versus 15% (RRR 1.593; P = 0.372) in patients with not otherwise specified histology. Median overall survival for nab-P/C versus sb-P/C in patients with SCC was 10.7 versus 9.5 months (HR 0.890; P = 0.310), and 12.4 versus 10.6 months (HR 1.208; P = 0.721) for patients with LC. nab-P/C produced significantly (P < 0.05) less grade 3/4 neuropathy and arthralgia, whereas sb-P/C produced less thrombocytopenia and anemia.

CONCLUSION(S)

First-line nab-P/C demonstrated a favorable risk-benefit profile in patients with NSCLC regardless of histology.