Characterization of a CrPME indicates its possible role in determining vindoline accumulation in Catharanthus roseus leaves.

The leaf-specific Catharanthus roseus alkaloid, vindoline, is the major bottleneck precursor in the production of scarce and costly anticancer bisindoles (vincristine and vinblastine). The final steps of its biosynthesis and storage occur in the laticifers. Earlier, we have shown that vindoline content is directly related to laticifer number. Pectin remodeling enzymes, like pectin methylesterase (PME), are known to be involved in laticifer development. A search in the croFGD yielded a leaf-abundant CrPME isoform that co-expressed with a few vindoline biosynthetic genes. Full-length cloning, tissue-specific expression profiling, and in silico analysis of CrPME were carried out. It was found to possess all the specific characteristics of a typical plant PME. Transient silencing (through VIGS) and overexpression of CrPME in C. roseus indicated a direct relationship between its expression and vindoline content. Comparative analysis of transcript abundance and enzyme activity in three familial C. roseus genotypes differing significantly in their vindoline content and laticifer count (CIM-Sushil > Dhawal > Nirmal) also corroborated the positive relationship of CrPME expression with vindoline content. This study highlights the possible role of CrPME, a cell wall remodeling enzyme, in modulating laticifer-associated secondary metabolism.

Vindoline ameliorates intestinal barrier damage in Crohn's disease mice through MAPK signaling pathway.

Intestinal inflammation and intestinal barrier damage are important pathological changes in Crohn's disease (CD). Vindoline is a natural monomer with anti-inflammatory effects. We employed CD model mice to explore the effect of Vindoline on CD-like colitis and the possible mechanism. Il-10-deficient (Il-10-/- ) mice and wild-type (WT) mice (both aged 15 weeks, male) were used to explore the effect of Vindoline on colitis and intestinal barrier damage, as well as macrophage-mediated inflammation. Bone-marrow-derived macrophages (BMDMs) and colonic organoids from mice were used to explore the inhibitory effect of Vindoline on macrophage-mediated inflammation and the protective effect on inflammation-induced intestinal barrier damage as well as the possible mechanism. We found that Vindoline significantly ameliorated colitis in CD mice, as evidenced by increased weight change and colon length and decreased the colon macroscopic injury score, histological inflammatory score, and the expression of pro-inflammatory mediators. Vindoline also protected against intestinal barrier damage in CD mice. Furthermore, Vindoline inhibited macrophage-mediated inflammation and protected against inflammation-induced intestinal barrier damage in the coculture system. In addition, Vindoline ameliorated colitis in CD mice by protecting against inflammation-induced intestinal barrier damage, which may be caused by inhibition of MAPK signaling pathway. This protective effect suggests that Vindoline has potential value for clinical application in the treatment of CD.

A Catharanthus roseus Fe(II)/α-ketoglutarate-dependent dioxygenase catalyzes a redox-neutral reaction responsible for vindolinine biosynthesis.

The Madagascar's periwinkle is the model plant for studies of plant specialized metabolism and monoterpenoid indole alkaloids (MIAs), and an important source for the anticancer medicine vinblastine. The elucidation of entire 28-step biosynthesis of vinblastine allowed further investigations for the formation of other remarkably complex bioactive MIAs. In this study, we describe the discovery and characterization of vindolinine synthase, a Fe(II)/α-ketoglutarate-dependent (Fe/2OG) dioxygenase, that diverts assembly of tabersonine to vinblastine toward the formation of three alternatively cyclized MIAs: 19S-vindolinine, 19R-vindolinine, and venalstonine. Vindolinine synthase catalyzes a highly unusual, redox-neutral reaction to form a radical from dehydrosecodine, which is further cyclized by hydrolase 2 to form the three MIA isomers. We further show the biosynthesis of vindolinine epimers from tabersonine using hydrolase 2 catalyzed reverse cycloaddition. While the occurrence of vindolinines is rare in nature, the more widely found venalstonine derivatives are likely formed from similar redox-neutral reactions by homologous Fe/2OG dioxygenases.

Effects of vindoline on rat cytochrome P450 isoform activities in vitro.

A specific ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) method has been described for the simultaneous determination of the metabolites of tacrine, bupropion, diclofenac, dextromethorphan and midazolam, which are the five probe drugs of the five cytochrome P450 (CYP450) isoforms CYP1A2, CYP2B, CYP2C11, CYP2D1 and CYP3A4. The inhibition degree was determined by calculating the IC50 . The chromatographic separation was performed on a C18 column with a mobile phase consisting of 0.1% formic acid and acetonitrile. The mass spectrometric analysis was conducted in positive electrospray ionization mode. The IC50 values of CYP1A2, CYP2B, CYP2C11, CYP2D1 and CYP3A were 113.4, 83.78, 22.50, 9.081 and 52.76 µmol L-1 , respectively. The in vitro results demonstrated that vindoline could inhibit CYP2D1 activity in rats, and weak inhibitory effect on CYP2C11 and CYP3A, but had no obvious effects on CYP1A2 and CYP2B.

Enhancement of Vindoline and Catharanthine Accumulation, Antioxidant Enzymes Activities, and Gene Expression Levels in Catharanthus roseus Leaves by Chitooligosaccharides Elicitation.

Catharanthus roseus (L.) G. Don is a plant belonging to the genus Catharanthus of the Apocynaceae family. It contains more than one hundred alkaloids, of which some exhibit significant pharmacological activities. Chitooligosaccharides are the only basic aminooligosaccharides with positively charged cations in nature, which can regulate plant growth and antioxidant properties. In this study, the leaves of Catharanthus roseus were sprayed with chitooligosaccharides of different molecular weights (1 kDa, 2 kDa, 3 kDa) and different concentrations (0.01 µg/mL, 0.1 µg/mL, 1 µg/mL and 10 µg/mL). The fresh weights of its root, stem and leaf were all improved after chitooligosaccharides treatments. More importantly, the chitooligosaccharides elicitor strongly stimulated the accumulation of vindoline and catharanthine in the leaves, especially with the treatment of 0.1 µg/mL 3 kDa chitooligosaccharides, the contents of them were increased by 60.68% and 141.54%, respectively. Furthermore, as the defensive responses, antioxidant enzymes activities (catalase, glutathione reductase, ascorbate peroxidase, peroxidase and superoxide dismutase) were enhanced under chitooligosaccharides treatments. To further elucidate the underlying mechanism, qRT-PCR was used to investigate the genes expression levels of secologanin synthase (SLS), strictosidine synthase (STR), strictosidine glucosidase (SGD), tabersonine 16-hydroxylase (T16H), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT), peroxidase 1 (PRX1) and octadecanoid-responsive Catharanthus AP2-domain protein 3 (ORCA3). All the genes were significantly up-regulated after chitooligosaccharides treatments, and the transcription abundance of ORCA3, SLS, STR, DAT and PRX1 reached a maximal level with 0.1 µg/mL 3 kDa chitooligosaccharides treatment. All these results suggest that spraying Catharanthus roseus leaves with chitooligosaccharides, especially 0.1 µg/mL of 3 kDa chitooligosaccharides, may effectively improve the pharmaceutical value of Catharanthus roseus.

VinCaP: a phase II trial of vinflunine in locally advanced and metastatic squamous carcinoma of the penis.

BACKGROUND: We investigated the first-line activity of vinflunine in patients with penis cancer. Cisplatin-based combinations are commonly used, but survival is not prolonged; many patients are unfit for such treatment or experience toxicity that outweighs clinical benefit. METHODS: Twenty-five patients with inoperable squamous carcinoma of the penis were recruited to a single-arm, Fleming-A'Hern exact phase II trial. Treatment comprised 4 cycles of vinflunine 320 mg/m2, given every 21 days. Primary endpoint was clinical benefit rate (CBR: objective responses plus stable disease) assessed after 4 cycles. Seven or more objective responses or disease stabilisations observed in 22 evaluable participants would exclude a CBR of <15%, with a true CBR of >40% being probable. RESULTS: Twenty-two participants were evaluable. Ten objective responses or disease stabilisations were confirmed. CBR was 45.5%, meeting the primary endpoint; partial response rate was 27.3%. Seven patients received >4 cycles of vinflunine. Dose reduction or treatment delay was required for 20% of cycles. In all, 68% of patients experienced at least one grade 3 adverse event. Two deaths on treatment were not caused by disease progression. CONCLUSIONS: Pre-specified clinical activity threshold was exceeded. Toxicity was in keeping with experience in other tumours. Vinflunine merits further study in this disease. TRIAL REGISTRATION: NCT02057913.

Synthesis of Novel Vindoline-Chrysin Hybrids.

Vinca alkaloids are well-known microtubule targeting agents, which are used against some types of cancer. Vindoline is one of the monomeric Vinca alkaloids which does not have anti-tumor effect, although its derivatives have serious impact on the field of these indole alkaloids. Chrysin is a secondary plant metabolite, which has broad-spectrum biological activity, among others anticancer activity. Chrysin had shown synergic effect with several antiproliferative compounds (e. g., doxorubicin, cisplatin and ciglitazone), therefore, we attempted the synthesis of a novel vindoline-chrysin hybrid molecule. However, in the first case a diphenylamine structure was isolated. The mechanism of the unexpected reaction was studied, and then the originally targeted hybrid was synthesized by a reverse route coupling. A further hybrid was produced using a different site of the molecule. The antitumor activities were determined against 60 human tumor cell lines (NCI60), where the aimed hybrid showed low micromolar GI50 values on most of the cell lines.

Tris(4-bromophenyl)aminium Hexachloroantimonate-Mediated Intermolecular C(sp2)-C(sp3) Free Radical Coupling of Vindoline with ß-Ketoesters and Related Compounds.

A powerful tris(4-bromophenyl)aminium hexachloroantimonate (BAHA) mediated regioselective intermolecular coupling reaction of vindoline with a wide range of substrates that include ß-ketoesters, ß-diketones, ß-ketoaldehydes, ß-ketonitriles, ß-ketolactones, ß-ketolactams, ß-cyanoesters, and malononitriles is detailed. The BAHA-promoted intermolecular sp3/sp2 coupling, representing a special class of selective C-H functionalization reactions with direct carbon-carbon bond formation, proceeds with generation of a quaternary center bound to the aryl C15 center of vindoline capable of accommodating of the vinblastine C16' methyl ester and functionalized for subsequent divergent heterocycle introduction. A comprehensive examination of the reaction scope, optimization of subtle reaction parameters, and key insights into the reaction mechanism are described. Contrary to what might be prevailing expectations, studies suggest the plausible mechanism entails initial single-electron oxidation of the substrate enolate, not vindoline, and subsequent regiospecific addition of the resulting electrophilic radical to vindoline. As such and beyond the new arylation reaction with vindoline, the studies define a host of new, previously unrecognized, applications of BAHA and related triarylaminium radical cations that arises from their ability to generate stabilized electrophilic radicals from ß-ketoesters and related substrates under nonreducing and metal-free conditions. Those exemplified herein include mediating stabilized enolate free radical arylation, dimerization, allylation, alkene addition, and α-oxidation reactions.

Stress responsiveness of vindoline accumulation in Catharanthus roseus leaves is mediated through co-expression of allene oxide cyclase with pathway genes.

Vindoline is an important alkaloid produced in Catharanthus roseus leaves. It is the more important monomer of the scarce and costly anticancer bisindole alkaloids, vincristine, and vinblastine, as unlike catharanthine (the other monomer), its biosynthesis is restricted to the leaves. Here, biotic (bacterial endophyte, phytoplasma, virus) and abiotic (temperature, salinity, SA, MeJa) factors were studied for their effect on vindoline accumulation in C. roseus. Variations in vindoline pathway-related gene expression were reflected in changes in vindoline content. Since allene oxide cyclase (CrAOC) is involved in jasmonate biosynthesis and MeJa modulates many vindoline pathway genes, the correlation between CrAOC expression and vindoline content was studied. It was taken up for full-length cloning, tissue-specific expression profiling, in silico analyses, and upstream genomic region analysis for cis-regulatory elements. Co-expression analysis of CrAOC with vindoline metabolism-related genes under the influence of aforementioned abiotic/biotic factors indicated its stronger direct correlation with the tabersonine-to-vindoline genes (t16h, omt, t3o, t3r, nmt, d4h, dat) as compared to the pre-tabersonine genes (tdc, str, sgd). Its expression was inversely related to that of downstream-acting peroxidase (prx) (except under temperature stress). Direct/positive relationship of CrAOC expression with vindoline content established it as a key gene modulating vindoline accumulation in C. roseus.

Efficient production of vindoline from tabersonine by metabolically engineered Saccharomyces cerevisiae.

Vindoline is a plant derived monoterpene indole alkaloid (MIA) with potential therapeutic applications and more importantly serves as the precursor to vinblastine and vincristine. To obtain a yeast strain for high yield production of vindoline from tabersonine, multiple metabolic engineering strategies were employed via the CRISPR/Cas9 mediated multiplex genome integration technology in the present study. Through increasing and tuning the copy numbers of the pathway genes, pairing cytochrome P450 enzymes (CYPs) with appropriate cytochrome P450 reductases (CPRs), engineering the microenvironment for functional expression of CYPs, enhancing cofactor supply, and optimizing fermentation conditions, the production of vindoline was increased to a final titer as high as ∼16.5 mg/L, which is more than 3,800,000-fold higher than the parent strain and the highest tabersonine to vindoline conversion yield ever reported. This work represents a key step of the engineering efforts to establish de novo biosynthetic pathways for vindoline, vinblastine, and vincristine.

Optimization of Tabersonine Methoxylation to Increase Vindoline Precursor Synthesis in Yeast Cell Factories.

Plant specialized metabolites are widely used in the pharmaceutical industry, including the monoterpene indole alkaloids (MIAs) vinblastine and vincristine, which both display anticancer activity. Both compounds can be obtained through the chemical condensation of their precursors vindoline and catharanthine extracted from leaves of the Madagascar periwinkle. However, the extensive use of these molecules in chemotherapy increases precursor demand and results in recurrent shortages, explaining why the development of alternative production approaches, such microbial cell factories, is mandatory. In this context, the precursor-directed biosynthesis of vindoline from tabersonine in yeast-expressing heterologous biosynthetic genes is of particular interest but has not reached high production scales to date. To circumvent production bottlenecks, the metabolic flux was channeled towards the MIA of interest by modulating the copy number of the first two genes of the vindoline biosynthetic pathway, namely tabersonine 16-hydroxylase and tabersonine-16-O-methyltransferase. Increasing gene copies resulted in an optimized methoxylation of tabersonine and overcame the competition for tabersonine access with the third enzyme of the pathway, tabersonine 3-oxygenase, which exhibits a high substrate promiscuity. Through this approach, we successfully created a yeast strain that produces the fourth biosynthetic intermediate of vindoline without accumulation of other intermediates or undesired side-products. This optimization will probably pave the way towards the future development of yeast cell factories to produce vindoline at an industrial scale.

Enhanced bioproduction of anticancer precursor vindoline by yeast cell factories.

The pharmaceutical industry faces a growing demand and recurrent shortages in many anticancer plant drugs given their extensive use in human chemotherapy. Efficient alternative strategies of supply of these natural products such as bioproduction by microorganisms are needed to ensure stable and massive manufacturing. Here, we developed and optimized yeast cell factories efficiently converting tabersonine to vindoline, a precursor of the major anticancer alkaloids vinblastine and vincristine. First, fine-tuning of heterologous gene copies restrained side metabolites synthesis towards vindoline production. Tabersonine to vindoline bioconversion was further enhanced through a rational medium optimization (pH, composition) and a sequential feeding strategy. Finally, a vindoline titre of 266 mg l-1 (88% yield) was reached in an optimized fed-batch bioreactor. This precursor-directed synthesis of vindoline thus paves the way towards future industrial bioproduction through the valorization of abundant tabersonine resources.

Physico-Chemical Stability of Admixtures of Vinflunine Used in Clinical Practice.

Procedure of administration of vinflunine is complex and consists of an Y-site injection with fluid at different speeds. Dose is diluted with 100 mL of 0.9% sodium chloride or 5% glucose and infused with half of the 500 mL bag of the fluid over 20 min; after that, the remaining fluid is administered at 300 mL/h. In this study, chemical stability and physical compatibility of vinflunine diluted with in 500 mL of both fluids were evaluated to simplify the administration procedure (infusion of mixture on 20 min followed by 250 mL of fluid at 300 mL/h). Physical compatibility and chemical stability were evaluated at two temperatures and protected from and exposed to light. Physical compatibility was evaluated by visual inspection, gravimetric control and measure of pH. A chromatographic method was developed to evaluate chemical stability. The dilution of vinflunine with 500 mL of fluid to final concentrations of 0.75 and 1.54 mg/mL is viable at doses used in clinical practice since admixtures are stable for 2 days at room temperature and at least 7 days under refrigeration. These results extend the expiration date of mixtures of vinflunine administered by the usual procedure and confirm the viability of the proposed procedure since administration is simplified and stability of vinflunine is guaranteed.

Restricted mean survival time as outcome measure in advanced urothelial bladder cancer: analysis of 4 clinical studies.

Background: The purpose of this study was to assess the effectiveness of immune checkpoint inhibitors (ICIs) in advanced urothelial carcinoma. Materials & methods: We selected seven cohorts of patients published in four clinical trials. The restricted mean survival time (RMST) was used to analyze survival curves, perform the comparisons and rank the treatments based on their effectiveness. The performance of RMST was compared with that of a network meta-analysis. Results: Three ICIs, vinflunine and best standard care, given as second line, were examined. ICIs significantly improved overall survival compared with best standard care. However, the survival gain was quite limited (up to 2.27 months). Post hoc pairwise comparisons were calculated. Conclusion: Our results summarized the efficacy of these treatments and confirmed the good methodological performance of RMST.

In Vitro Antidiabetic and Antioxidant Effects of Different Extracts of Catharanthus roseus and Its Indole Alkaloid, Vindoline.

The Catharanthus roseus plant has been used traditionally to treat diabetes mellitus. Scientific evidence supporting the antidiabetic effects of this plant's active ingredient-vindoline has not been fully evaluated. In this study, extracts of C. roseus and vindoline were tested for antioxidant activities, alpha amylase and alpha glucosidase inhibitory activities and insulin secretory effects in pancreatic RIN-5F cell line cultured in the absence of glucose, at low and high glucose concentrations. The methanolic extract of the plant showed the highest antioxidant activities in addition to the high total polyphenolic content (p < 0.05). The HPLC results exhibited increased concentration of vindoline in the dichloromethane and the ethylacetate extracts. Vindoline showed noticeable antioxidant activity when compared to ascorbic acid at p < 0.05 and significantly improved the in vitro insulin secretion. The intracellular reactive oxygen species formation in glucotoxicity-induced cells was significantly reduced following treatment with vindoline, methanolic and the dichloromethane extracts when compared to the high glucose untreated control (p < 0.05). Plant extracts and vindoline showed weaker inhibitory effects on the activities of carbohydrate metabolizing enzymes when compared to acarbose, which inhibited the activities of the enzymes by 80%. The plant extracts also exhibited weak alpha amylase and alpha glucosidase inhibitory effects.

Final Overall Survival Analysis of the SOGUG Phase 2 MAJA Study: Maintenance Vinflunine Versus Best Supportive Care After First-Line Chemotherapy in Advanced Urothelial Carcinoma.

INTRODUCTION: The MAJA study compared vinflunine (VFL) plus best supportive care (BSC) maintenance therapy versus BSC alone in advanced urothelial carcinoma responsive to first-line chemotherapy. The primary end point of progression-free survival was achieved. We present the final overall survival (OS) and long-term follow-up safety analyses. PATIENTS AND METHODS: Patients were enrolled, and a subsequent post hoc analysis was performed on the basis of radiologic response or stabilization to first-line cisplatin/gemcitabine (CG) chemotherapy (4-6 cycles), according to Response Evaluation Criteria in Solid Tumors (RECIST). VFL + BSC versus BSC alone were randomly assigned until disease progression. RESULTS: At final analysis, 58 patients (66.7%) had died while 29 (33.3%) had survived; the BSC arm had higher mortality (VFL + BSC, n = 26, 59.1% vs. BSC, n = 32, 74.4%). Median follow-up of surviving patients was 38.8 months (interquartile range, 23.8-61.6). Median OS was 16.7 months (95% confidence interval, 0-34.5) in VFL and 13.2 months (95% confidence interval, 6-20.4) in the BSC groups (hazard ratio, 0.736; 95% confidence interval, 0.44-1.24, P = .182). Post hoc group division did not affect median OS in either study arm. CONCLUSION: Final analysis supported a benefit of VFL in maintenance therapy in patients with disease control after first-line treatment with CG, with no unexpected long-term adverse effects. The study was insufficiently powered to show a significant OS advantage.

Synthesis and Cytotoxic Activity of New Vindoline Derivatives Coupled to Natural and Synthetic Pharmacophores.

New Vinca alkaloid derivatives were synthesized to improve the biological activity of the natural alkaloid vindoline. To this end, experiments were performed to link vindoline with various structural units, such as amino acids, a 1,2,3-triazole derivative, morpholine, piperazine and N-methylpiperazine. The structure of the new compounds was characterized by NMR spectroscopy and mass spectrometry (MS). Several compounds exhibited in vitro antiproliferative activity against human gynecological cancer cell lines with IC50 values in the low micromolar concentration range.

Pembrolizumab versus chemotherapy in recurrent, advanced urothelial cancer in Japanese patients: a subgroup analysis of the phase 3 KEYNOTE-045 trial.

BACKGROUND: The open-label, randomized, active-controlled KEYNOTE-045 study (NCT02256436) showed that second-line pembrolizumab significantly improved overall survival (OS) of patients with advanced/metastatic urothelial cancer (UC) that progressed after first-line platinum-containing chemotherapy, compared with standard chemotherapy (paclitaxel, docetaxel, or vinflunine). Pembrolizumab is approved for patients with bladder cancer in Japan. PATIENTS AND METHODS: Analysis was performed in the subgroup of Japanese patients enrolled in the KEYNOTE-045 study. Coprimary end points were OS and progression-free survival (PFS). Objective response rate (ORR) and safety were secondary end points. RESULTS: Fifty-two Japanese patients (pembrolizumab, n = 30; chemotherapy, n = 22) were followed up for a median of 26.1 months. Patients who received pembrolizumab compared with chemotherapy had a 19% lower risk for death (hazard ratio [HR] 0.81, 95% CI 0.44-1.50); after adjusting for baseline covariates, the HR for OS was 0.61 (95% CI 0.32-1.15). The 24-month OS rate was higher with pembrolizumab (26.9% vs 14.3%). PFS was 2.0 and 4.9 months for pembrolizumab and chemotherapy, respectively (HR 1.71, 95% CI 0.95-3.08). ORR was similar for pembrolizumab and chemotherapy (20.0% vs 18.2%); durability of response was higher with pembrolizumab: 67% and 33% of patients, respectively, maintained a response for > 12 months. Treatment-related adverse events, including grade 3-5 events, occurred less frequently with pembrolizumab. CONCLUSIONS: Pembrolizumab provided durable antitumor activity in patients with locally advanced/metastatic UC that progressed after platinum-containing chemotherapy in the overall population and in the Japanese subgroup; safety profile was consistent with that previously observed for pembrolizumab.

Vinflunine/gemcitabine versus carboplatin/gemcitabine as first-line treatment in cisplatin-ineligible patients with advanced urothelial carcinoma: A randomised phase II trial (VINGEM).

BACKGROUND: The present study (VINGEM) is the first randomised trial comparing vinflunine/gemcitabine (VG) to standard carboplatin/gemcitabine (CG) in patients with advanced urothelial carcinoma (aUC) ineligible for treatment with cisplatin. PATIENTS AND METHODS: Patients with aUC, creatinine clearance 30-60 ml/min, performance status ≤1 and no prior chemotherapy for metastatic disease were randomised to the experimental arm (vinflunine 280 or 250 mg/m2 day 1, gemcitabine 1000 mg/m2 days 1 and 8, q21 days) or the control arm (carboplatin AUC 4.5 day 1, gemcitabine 1000 mg/m2 days 1 and 8, q21 days). Primary end-point was progression-free survival (PFS). RESULTS: Sixty-two patients were randomised; a total of 59 patients were treated (29 VG, 30 CG). There was no significant difference in PFS between the treatment arms: median 6.2 months for VG versus 6.3 months for CG (hazard ratio [HR]: 0.75, 95% confidence interval [CI]: 0.44-1.28; P = 0.293). Median overall survival was 12.5 months for VG versus 10.6 months for CG. The overall response rate (ORR) was higher in the VG arm than in the CG arm (63% versus 40%) but was not statistically significant in the intention-to-treat analysis. Furthermore, VG showed a high complete response (CR) rate, 22% versus 3% in CG. In the per-protocol group, both ORR and CR were significantly higher for VG than for CG. The most common adverse events (AEs) were fatigue, haematological toxicities, gastrointestinal disorders and nausea/vomiting. Common grade III/IV AEs were neutropenia (VG 62%, CG 43%), thrombocytopenia (VG 7%, CG 37%) and febrile neutropenia (VG 31%, CG 7%). CONCLUSIONS: The combination of VG did not improve PFS compared with standard treatment with CG in patients unfit for cisplatin due to renal impairment. The response rate of VG indicates, however, an active regimen and warrants further studies. CLINICALTRIALS. GOV NUMBER: NCT02665039.