RESUMEN
Cibisatamab is a bispecific antibody-based construct targeting carcinoembryonic antigen (CEA) on tumour cells and CD3 epsilon chain as a T-cell engager. Here we evaluated cibisatamab for advanced CEA-positive solid tumours in two open-label Phase 1 dose-escalation and -expansion studies: as a single agent with or without obinutuzumab in S1 (NCT02324257) and with atezolizumab in S2 (NCT02650713). Primary endpoints were safety, dose finding, and pharmacokinetics in S1; safety and dose finding in S2. Secondary endpoints were anti-tumour activity (including overall response rate, ORR) and pharmacodynamics in S1; anti-tumour activity, pharmacodynamics and pharmacokinetics in S2. S1 and S2 enrolled a total of 149 and 228 patients, respectively. Grade ≥3 cibisatamab-related adverse events occurred in 36% of S1 and 49% of S2 patients. The ORR was 4% in S1 and 7% in S2. In S2, patients with microsatellite stable colorectal carcinoma (MSS-CRC) given flat doses of cibisatamab and atezolizumab demonstrated an ORR of 14%. In S1 and S2, 40% and 52% of patients, respectively, developed persistent anti-drug antibodies (ADAs). ADA appearance could be mitigated by obinutuzumab-pretreatment, with 8% of patients having persistent ADAs. Overall, cibisatamab warrants further exploration in immunotherapy combination strategies for MSS-CRC.
Asunto(s)
Anticuerpos Biespecíficos , Anticuerpos Monoclonales Humanizados , Complejo CD3 , Antígeno Carcinoembrionario , Neoplasias , Humanos , Anticuerpos Biespecíficos/uso terapéutico , Anticuerpos Biespecíficos/farmacocinética , Anticuerpos Biespecíficos/administración & dosificación , Anticuerpos Biespecíficos/efectos adversos , Anticuerpos Biespecíficos/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/farmacocinética , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Femenino , Masculino , Persona de Mediana Edad , Anciano , Complejo CD3/inmunología , Adulto , Antígeno Carcinoembrionario/inmunología , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinéticaRESUMEN
BACKGROUND: Before the availability of immunotherapy, chemotherapy was standard first-line therapy for non-small-cell lung cancer (NSCLC) lacking actionable gene alterations. Preclinical evidence suggests chemotherapy is immunomodulatory, supporting chemotherapy/immunotherapy combinations. Atezolizumab, anti-programmed death ligand-1 (PD-L1) antibody, blocks programmed cell death protein-1 and B7.1 interaction with PD-L1. GP28328 (NCT01633970) assessed atezolizumab with chemotherapy in multiple tumours; we report results for advanced, treatment-naïve NSCLC. METHODS: Patients received atezolizumab plus carboplatin with paclitaxel (Arm C: atezo/cb/pac), pemetrexed (Arm D: atezo/cb/pem, maintenance pemetrexed permitted), or nab-paclitaxel (Arm E: atezo/cb/nab-pac), four-six cycles, then atezolizumab maintenance. Primary end-point was safety; secondary end-points were objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). RESULTS: Seventy-six NSCLC patients were enrolled (n = 25, 25 and 26 for Arms C, D and E, respectively). Common treatment-related grade III/IV adverse events were neutropenia (36% atezo/cb/pac, 36% atezo/cb/pem, 42% atezo/cb/nab-pac) and anaemia (16% atezo/cb/pac, 16% atezo/cb/pem, 31% atezo/cb/nab-pac). Confirmed ORRs were 36% atezo/cb/pac, 68% atezo/cb/pem (one complete response [CR]) and 46% atezo/cb/nab-pac (four CRs). Median PFS was 7.1 months, (95% confidence interval [CI]: 4.2-8.3), 8.4 months (95% CI: 4.7-11) and 5.7 months (95% CI: 4.4-14.8), respectively. Median OS was 12.9 months (95% CI: 8.8-21.3), 18.9 months (95% CI: 9.9-27.4) and 17.0 months (95% CI: 12.7-not evaluable), respectively. CONCLUSION: Atezolizumab with chemotherapy was well tolerated with encouraging efficacy, though the analysis was limited by small numbers. NSCLC chemotherapy combination studies are ongoing. CLINICALTRIALS. GOV IDENTIFIER: NCT01633970.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carboplatino/administración & dosificación , Carboplatino/efectos adversos , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neutropenia/inducido químicamente , Análisis de Supervivencia , Factores de Tiempo , Resultado del TratamientoRESUMEN
Most patients with advanced non-small cell lung cancer (NSCLC) have a poor prognosis and receive limited benefit from conventional treatments, especially in later lines of therapy. In recent years, several novel therapies have been approved for second- and third-line treatment of advanced NSCLC. In light of these approvals, it is valuable to understand the uptake of these new treatments in routine clinical practice and their impact on patient care. A systematic literature search was conducted in multiple scientific databases to identify observational cohort studies published between January 2010 and March 2017 that described second- or third-line treatment patterns and clinical outcomes in patients with advanced NSCLC. A qualitative data synthesis was performed because a meta-analysis was not possible due to the heterogeneity of the study populations. A total of 12 different study cohorts in 15 articles were identified. In these cohorts, single-agent chemotherapy was the most commonly administered treatment in both the second- and third-line settings. In the 5 studies that described survival from the time of second-line treatment initiation, median overall survival ranged from 4.6 months (95% CI, 3.8-5.7) to 12.8 months (95% CI, 10.7-14.5). There was limited information on the use of biomarker-directed therapy in these patient populations. This systematic literature review offers insights into the adoption of novel therapies into routine clinical practice for second- and third-line treatment of patients with advanced NSCLC. This information provides a valuable real-world context for the impact of recently approved treatments for advanced NSCLC.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Bases de Datos Factuales , Quimioterapia Combinada , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Estadificación de Neoplasias , Inhibidores de Proteínas Quinasas/uso terapéutico , Tasa de SupervivenciaRESUMEN
BACKGROUND: Atezolizumab is a humanised antiprogrammed death-ligand 1 (PD-L1) monoclonal antibody that inhibits PD-L1 and programmed death-1 (PD-1) and PD-L1 and B7-1 interactions, reinvigorating anticancer immunity. We assessed its efficacy and safety versus docetaxel in previously treated patients with non-small-cell lung cancer. METHODS: We did a randomised, open-label, phase 3 trial (OAK) in 194 academic or community oncology centres in 31 countries. We enrolled patients who had squamous or non-squamous non-small-cell lung cancer, were 18 years or older, had measurable disease per Response Evaluation Criteria in Solid Tumors, and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients had received one to two previous cytotoxic chemotherapy regimens (one or more platinum based combination therapies) for stage IIIB or IV non-small-cell lung cancer. Patients with a history of autoimmune disease and those who had received previous treatments with docetaxel, CD137 agonists, anti-CTLA4, or therapies targeting the PD-L1 and PD-1 pathway were excluded. Patients were randomly assigned (1:1) to intravenously receive either atezolizumab 1200 mg or docetaxel 75 mg/m2 every 3 weeks by permuted block randomisation (block size of eight) via an interactive voice or web response system. Coprimary endpoints were overall survival in the intention-to-treat (ITT) and PD-L1-expression population TC1/2/3 or IC1/2/3 (≥1% PD-L1 on tumour cells or tumour-infiltrating immune cells). The primary efficacy analysis was done in the first 850 of 1225 enrolled patients. This study is registered with ClinicalTrials.gov, number NCT02008227. FINDINGS: Between March 11, 2014, and April 29, 2015, 1225 patients were recruited. In the primary population, 425 patients were randomly assigned to receive atezolizumab and 425 patients were assigned to receive docetaxel. Overall survival was significantly longer with atezolizumab in the ITT and PD-L1-expression populations. In the ITT population, overall survival was improved with atezolizumab compared with docetaxel (median overall survival was 13·8 months [95% CI 11·8-15·7] vs 9·6 months [8·6-11·2]; hazard ratio [HR] 0·73 [95% CI 0·62-0·87], p=0·0003). Overall survival in the TC1/2/3 or IC1/2/3 population was improved with atezolizumab (n=241) compared with docetaxel (n=222; median overall survival was 15·7 months [95% CI 12·6-18·0] with atezolizumab vs 10·3 months [8·8-12·0] with docetaxel; HR 0·74 [95% CI 0·58-0·93]; p=0·0102). Patients in the PD-L1 low or undetectable subgroup (TC0 and IC0) also had improved survival with atezolizumab (median overall survival 12·6 months vs 8·9 months; HR 0·75 [95% CI 0·59-0·96]). Overall survival improvement was similar in patients with squamous (HR 0·73 [95% CI 0·54-0·98]; n=112 in the atezolizumab group and n=110 in the docetaxel group) or non-squamous (0·73 [0·60-0·89]; n=313 and n=315) histology. Fewer patients had treatment-related grade 3 or 4 adverse events with atezolizumab (90 [15%] of 609 patients) versus docetaxel (247 [43%] of 578 patients). One treatment-related death from a respiratory tract infection was reported in the docetaxel group. INTERPRETATION: To our knowledge, OAK is the first randomised phase 3 study to report results of a PD-L1-targeted therapy, with atezolizumab treatment resulting in a clinically relevant improvement of overall survival versus docetaxel in previously treated non-small-cell lung cancer, regardless of PD-L1 expression or histology, with a favourable safety profile. FUNDING: F. Hoffmann-La Roche Ltd, Genentech, Inc.
Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Antineoplásicos/administración & dosificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Taxoides/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Supervivencia sin Enfermedad , Docetaxel , Esquema de Medicación , Femenino , Humanos , Infusiones Intravenosas , Estimación de Kaplan-Meier , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
Anti-tumour immune activation by checkpoint inhibitors leads to durable responses in a variety of cancers, but combination approaches are required to extend this benefit beyond a subset of patients. In preclinical models tumour-derived VEGF limits immune cell activity while anti-VEGF augments intra-tumoral T-cell infiltration, potentially through vascular normalization and endothelial cell activation. This study investigates how VEGF blockade with bevacizumab could potentiate PD-L1 checkpoint inhibition with atezolizumab in mRCC. Tissue collections are before treatment, after bevacizumab and after the addition of atezolizumab. We discover that intra-tumoral CD8(+) T cells increase following combination treatment. A related increase is found in intra-tumoral MHC-I, Th1 and T-effector markers, and chemokines, most notably CX3CL1 (fractalkine). We also discover that the fractalkine receptor increases on peripheral CD8(+) T cells with treatment. Furthermore, trafficking lymphocyte increases are observed in tumors following bevacizumab and combination treatment. These data suggest that the anti-VEGF and anti-PD-L1 combination improves antigen-specific T-cell migration.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Antígenos de Neoplasias/inmunología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Bevacizumab/farmacología , Linfocitos T CD8-positivos/efectos de los fármacos , Carcinoma de Células Renales/tratamiento farmacológico , Neoplasias Renales/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Antígeno B7-H1/antagonistas & inhibidores , Bevacizumab/uso terapéutico , Linfocitos T CD8-positivos/inmunología , Carcinoma de Células Renales/inmunología , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/secundario , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Sinergismo Farmacológico , Femenino , Humanos , Riñón/patología , Neoplasias Renales/inmunología , Neoplasias Renales/patología , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidoresRESUMEN
BACKGROUND: Outcomes are poor for patients with previously treated, advanced or metastatic non-small-cell lung cancer (NSCLC). The anti-programmed death ligand 1 (PD-L1) antibody atezolizumab is clinically active against cancer, including NSCLC, especially cancers expressing PD-L1 on tumour cells, tumour-infiltrating immune cells, or both. We assessed efficacy and safety of atezolizumab versus docetaxel in previously treated NSCLC, analysed by PD-L1 expression levels on tumour cells and tumour-infiltrating immune cells and in the intention-to-treat population. METHODS: In this open-label, phase 2 randomised controlled trial, patients with NSCLC who progressed on post-platinum chemotherapy were recruited in 61 academic medical centres and community oncology practices across 13 countries in Europe and North America. Key inclusion criteria were Eastern Cooperative Oncology Group performance status 0 or 1, measurable disease by Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), and adequate haematological and end-organ function. Patients were stratified by PD-L1 tumour-infiltrating immune cell status, histology, and previous lines of therapy, and randomly assigned (1:1) by permuted block randomisation (with a block size of four) using an interactive voice or web system to receive intravenous atezolizumab 1200 mg or docetaxel 75 mg/m(2) once every 3 weeks. Baseline PD-L1 expression was scored by immunohistochemistry in tumour cells (as percentage of PD-L1-expressing tumour cells TC3≥50%, TC2≥5% and <50%, TC1≥1% and <5%, and TC0<1%) and tumour-infiltrating immune cells (as percentage of tumour area: IC3≥10%, IC2≥5% and <10%, IC1≥1% and <5%, and IC0<1%). The primary endpoint was overall survival in the intention-to-treat population and PD-L1 subgroups at 173 deaths. Biomarkers were assessed in an exploratory analysis. We assessed safety in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01903993. FINDINGS: Patients were enrolled between Aug 5, 2013, and March 31, 2014. 144 patients were randomly allocated to the atezolizumab group, and 143 to the docetaxel group. 142 patients received at least one dose of atezolizumab and 135 received docetaxel. Overall survival in the intention-to-treat population was 12·6 months (95% CI 9·7-16·4) for atezolizumab versus 9·7 months (8·6-12·0) for docetaxel (hazard ratio [HR] 0·73 [95% CI 0·53-0·99]; p=0·04). Increasing improvement in overall survival was associated with increasing PD-L1 expression (TC3 or IC3 HR 0·49 [0·22-1·07; p=0·068], TC2/3 or IC2/3 HR 0·54 [0·33-0·89; p=0·014], TC1/2/3 or IC1/2/3 HR 0·59 [0·40-0·85; p=0·005], TC0 and IC0 HR 1·04 [0·62-1·75; p=0·871]). In our exploratory analysis, patients with pre-existing immunity, defined by high T-effector-interferon-γ-associated gene expression, had improved overall survival with atezolizumab. 11 (8%) patients in the atezolizumab group discontinued because of adverse events versus 30 (22%) patients in the docetaxel group. 16 (11%) patients in the atezolizumab group versus 52 (39%) patients in the docetaxel group had treatment-related grade 3-4 adverse events, and one (<1%) patient in the atezolizumab group versus three (2%) patients in the docetaxel group died from a treatment-related adverse event. INTERPRETATION: Atezolizumab significantly improved survival compared with docetaxel in patients with previously treated NSCLC. Improvement correlated with PD-L1 immunohistochemistry expression on tumour cells and tumour-infiltrating immune cells, suggesting that PD-L1 expression is predictive for atezolizumab benefit. Atezolizumab was well tolerated, with a safety profile distinct from chemotherapy. FUNDING: F Hoffmann-La Roche/Genentech Inc.
Asunto(s)
Anticuerpos/uso terapéutico , Antineoplásicos/uso terapéutico , Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Taxoides/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Supervivencia sin Enfermedad , Docetaxel , Europa (Continente)/epidemiología , Femenino , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , América del Norte/epidemiología , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: Elderly patients are often under-represented in clinical trials of metastatic colorectal cancer. We aimed to assess the efficacy and safety of bevacizumab plus capecitabine compared with capecitabine alone in elderly patients with metastatic colorectal cancer. METHODS: For this open-label, randomised phase 3 trial, patients aged 70 years and older with previously untreated, unresectable, metastatic colorectal cancer, who were not deemed to be candidates for oxaliplatin-based or irinotecan-based chemotherapy regimens, were randomly assigned in a 1:1 ratio via an interactive voice-response system, stratified by performance status and geographical region. Treatment consisted of capecitabine (1000 mg/m(2) orally twice a day on days 1-14) alone or with bevacizumab (7·5 mg/kg intravenously on day 1), given every 3 weeks until disease progression, unacceptable toxic effects, or withdrawal of consent. Efficacy analyses were based on the intention-to-treat population. The primary endpoint was progression-free survival. The trial is registered with ClinicalTrials.gov, number NCT00484939. FINDINGS: From July 9, 2007, to Dec 14, 2010, 280 patients with a median age of 76 years (range 70-87) were recruited from 40 sites across ten countries. Patients were randomly assigned to receive either bevacizumab plus capecitabine (n=140) or capecitabine only (n=140). Progression-free survival was significantly longer with bevacizumab and capecitabine than with capecitabine alone (median 9·1 months [95% CI 7·3-11·4] vs 5·1 months [4·2-6·3]; hazard ratio 0·53 [0·41-0·69]; p<0·0001). Treatment-related adverse events of grade 3 or worse occurred in 53 (40%) patients in the combination group and 30 (22%) in the capecitabine group, and treatment-related serious adverse events in 19 (14%) and 11 (8%) patients. The most common grade 3 or worse adverse events of special interest for bevacizumab or chemotherapy were hand-foot syndrome (21 [16%] vs nine [7%]), diarrhoea (nine [7%] vs nine [7%]), and venous thromboembolic events (11 [8%] vs six [4%]). Treatment-related deaths occurred in five patients in the combination group and four in the capecitabine group. The most common any-grade adverse event of special interest for bevacizumab was haemorrhage (34 [25%] vs nine [7%]). INTERPRETATION: The combination of bevacizumab and capecitabine is an effective and well-tolerated regimen for elderly patients with metastatic colorectal cancer. FUNDING: F Hoffmann-La Roche.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados/administración & dosificación , Bevacizumab , Capecitabina , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/análogos & derivados , Estudios de Seguimiento , Humanos , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/secundario , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/secundario , Masculino , Estadificación de Neoplasias , Pronóstico , Tasa de SupervivenciaRESUMEN
PURPOSE: his analysis pooled individual patient data from randomized controlled trials (RCTs) to more thoroughly examine clinical outcomes when adding bevacizumab to chemotherapy for patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: Patient data were pooled from the first-line AVF2107, NO16966, ARTIST, AVF0780, AVF2192, and AGITG MAX RCTs and the second-line E3200 RCT. All analyses were based on the intent-to-treat population. To assess differences in time-to-event variables by treatment (chemotherapy with or without placebo vs. chemotherapy plus bevacizumab), stratified random-effects (overall) and fixed-effects (subgroup comparisons) models were used to estimate pooled hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: The analysis population comprised 3,763 patients (1,773 chemotherapy with or without placebo; 1,990 chemotherapy plus bevacizumab). The addition of bevacizumab to chemotherapy was associated with statistically significant increases in overall survival (OS; HR, 0.80; 95% CI, 0.71-0.90) and progression-free survival (PFS; HR, 0.57; 95% CI, 0.46-0.71). The effects on OS and PFS across subgroups defined by chemotherapy backbone (oxaliplatin-based, irinotecan-based), extent of disease (liver metastases only, extensive disease), age (<65, ≥65 years), Eastern Cooperative Oncology Group performance status (0, ≥1), and KRAS status (wild-type, mutant) were consistent with the overall analysis. Incidence rates of grade ≥3 hypertension, proteinuria, bleeding, wound-healing complications, gastrointestinal perforations, and thromboembolic events were increased with bevacizumab treatment. CONCLUSION: The use of bevacizumab with chemotherapy resulted in statistically significant increases in OS and PFS for patients with mCRC. The PFS benefit extended across the clinically relevant subgroups examined. The observed safety profile of bevacizumab was consistent with that reported in individual trials.
Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Neoplasias Colorrectales/tratamiento farmacológico , Anciano , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/efectos adversos , Bevacizumab , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Neoplasias Colorrectales/irrigación sanguínea , Neoplasias Colorrectales/patología , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del TratamientoRESUMEN
Random peptide ligands displayed on viral capsids are emerging tools for selection of targeted gene transfer vectors even without prior knowledge of the potential target cell receptor. We have previously introduced adeno-associated viral (AAV)-displayed peptide libraries that ensure encoding of displayed peptides by the packaged AAV genome. A major limitation of these libraries is their contamination with wild-type (wt) AAV. Here we describe a novel and improved library production system that reliably avoids generation of wt AAV by use of a synthetic cap gene. Selection of targeted AAV vectors from wt-containing and the novel wt-free libraries on cell types with different permissivity for wt AAV2 replication suggested the superiority of the wt-free library. However, from both libraries highly specific peptide sequence motifs were selected which improved transduction of cells with moderate or low permissivity for AAV2 replication. Strong reduction of HeLa cell transduction compared to wt AAV2 and only low level transduction of non-target cells by some selected clones showed that not only the efficiency but also the specificity of gene transfer was improved. In conclusion, our study validates and improves the unique potential of virus display libraries for the development of targeted gene transfer vectors.