Dose Of Bevacizumab Research Articles

Short-term efficacy of intravitreal Aflibercept injections for retinal angiomatous proliferation

BackgroundTo evaluate the short-term efficacy of intravitreal injections of aflibercept (IVA) to treat retinal angiomatous proliferation (RAP) and identify factors related to functional outcomes.MethodsThis retrospective case series consisted of 19 eyes in 19 patients with RAP. All 19 eyes received 3 monthly consecutive IVA. The primary outcome measures were best-corrected visual acuity (BCVA) and central retinal thickness (CRT) after the last IVA.ResultsOf the 19 treated eyes, 8 (42%) were pre-treated with 1 dose of bevacizumab one month prior to the initiation of treatment with aflibercept. BCVA was significantly improved and CRT was significantly reduced after 3 consecutive IVAs (P = 0.014 and P = 0.0002, respectively). Stabilization or improvement in BCVA was observed in 17 eyes (90%) treated with IVA. Eyes with baseline fibrovascular pigment epithelial detachment (PED) showed no significant gain in BCVA, and fibrovascular PED was negatively correlated with final BCVA (Spearman’s correlation coefficient = − 0.481, P = 0.037). The mean follow-up was 3.5 ± 0.5 months.ConclusionsIn this short-term study, three consecutive IVAs showed efficacy for improving vision and reducing retinal edema in RAP patients. Eyes with fibrovascular PED showed poorer responses, and the presence of fibrovascular PED at baseline was negatively correlated with visual outcomes.

Lack of functional normalisation of tumour vessels following anti-angiogenic therapy in glioblastoma

Neo-angiogenesis represents an important factor for the delivery of oxygen and nutrients to a growing tumour, and is considered to be one of the main pathodiagnostic features of glioblastomas (GBM). Anti-angiogenic therapy by vascular endothelial growth factor (VEGF) blocking agents has been shown to lead to morphological vascular normalisation resulting in a reduction of contrast enhancement as seen by magnetic resonance imaging (MRI). Yet the functional consequences of this normalisation and its potential for improved delivery of cytotoxic agents to the tumour are not known. The presented study aimed at determining the early physiologic changes following bevacizumab treatment. A time series of perfusion MRI and hypoxia positron emission tomography (PET) scans were acquired during the first week of treatment, in two human GBM xenograft models treated with either high or low doses of bevacizumab. We show that vascular morphology was normalised over the time period investigated, but vascular function was not improved, resulting in poor tumoural blood flow and increased hypoxia.

Long-term growth and development in 268 bevacizumab (BEV)-treated and 135 control pediatric/adolescent patients (pts): An integrated analysis.

10554 Background: BEV has an established safety profile in adults, but long-term data in children are limited. This analysis examined the effects of BEV on growth/development in pediatric/adolescent pts. Methods: Data (height, weight, body mass index [BMI], bone age data) were pooled (5 trials): NCT00643565 (Ph2/soft tissue sarcoma); NCT01390948 (Ph2/high-grade glioma); NCT00085111 (Ph1/refractory solid tumors); NCT00667342 (Ph2/osteosarcoma); NCT00381797 (Ph2/glioma, medulloblastoma, ependymoma). Pts (<18 yrs old) received ≥1 dose of BEV + chemotherapy (CT) (n=268) or CT alone (n=135). Analyses were exploratory/descriptive. Reference growth data: WHO (<2 yrs); Centres for Disease Control (≥2 yrs). Results: Across the trials, mean number of BEV administrations per pt ranged 5.6–19.9 (dose 5–15mg/kg every 2/3 weeks). Median follow-up time, months (range): BEV+CT, 37.9 (2.4–64.2); CT, 22.9 (2.8–69.2). At baseline, median height, weight, and BMI were close to that of the reference population (mean standard deviation scores [SDS] close to 0). Over 60 months, a slight decline was observed in the mean SDS for height and weight in both arms in this cohort with different tumors/treatments (Table), but remained within normal range of healthy children. Trends were similar for BMI. No delay in growth velocity or bone age in BEV-treated pts vs CT only was observed up to 3 yrs, regardless of age/gender. A subgroup analysis of pts in the growth hormone-dependent development phase was consistent with the overall results. Conclusions: In this analysis, BEV inclusion in the treatment regimen did not have a negative impact on pediatric growth/development beyond that of CT alone. [Table: see text]

Identifying factors to predict benefit from bevacizumab in progressive glioblastoma multiforme (GBM).

e13515 Background: Bevacizumab (BEV) has demonstrated activity in GBM, but the benefits have not been clearly defined in prospective randomised phase III trials. Some patients continue BEV for extended periods but little is known about predictors of clinical benefit. It has been suggested that a less intensive dose schedule might offer similar benefits. Methods: In a retrospective analysis of a National Neuro-Oncology centre database we examined biomarkers of BEV benefit on overall survival (OS), including age at diagnosis, time from diagnosis to BEV start, MGMT methylation and IDH-1 status. We compared those who derived clinical benefit (OS of ≥6-months) to those with limited clinical benefit (OS <6 months). At our Institution, there is variable practice between Neuro-Oncologists in terms of BEV dose schedule. In this homogeneous patient population, we examined whether OS was similar for patients who received standard BEV dosing (10mg/kg q 2wks or 15mg/kg q 3wks) or reduced intensity BEV (5mg/kg q 2wks or 7.5mg/kg q 3wks). Results: Between January 1st 2010 and Dec 31st 2016, 170 patients received BEV for progressive GBM. Median OS was 5.5 months (Range: 0.5-54). OS was 42%, 18% and 2% at 6-, 12- and 24-months, respectively. No significant predictors of clinical benefit were identified (table). Importantly, median OS was similar for patients who received standard (N=94) vs. reduced intensity (N=76) BEV (5.2 vs. 5.6mo respectively), p=0.74. Conclusions: In this large cohort of patients, we did not identify predictors of benefit from BEV. OS was similar in patients who received standard or reduced intensity BEV. Given the cost of BEV, these results have important implications for value in cancer care. [Table: see text]

Phase II trial of the autophagy inhibitor hydroxychloroquine with FOLFOX and bevacizumab in front line treatment of metastatic colorectal cancer.

3545 Background: Colorectal cancer (CRC) cells can become resistant to chemotherapy and anti-angiogenic therapy through autophagy. The antimalarial agent hydroxychloroquine (HCQ) is a potent inhibitor of autophagy, and in vivo studies in CRC cell models show significant decrease tumor volume when these autophagy inhibitors were combined with oxaliplatin and bevacizumab. We previously reported safety with HCQ 600mg BID in combination with standard front-line FOLFOX and bevacizumab in a Phase I study in metastatic CRC patients. We report the results of a single-arm phase II trial of patients with previously untreated stage IV CRC with good performance status and adequate hematologic and biochemical indices. Methods: Patients were treated with standard doses of mFOLFOX6 and bevacizumab with HCQ 600mg BID. Imaging was obtained every 2 months. Results: 37 patients were enrolled, 62% male, 89% Caucasian, median age 61, 65% ECOG PS 0, and 73% colon primary. Twenty-eight patients were evaluable for response as 2 patients did not start therapy and 7 patients withdrew prior to first response assessment. The ORR was 68% with an 11% CR rate. The median time to response was 3.1 months. Responses were independent of genomic aberrations within tumor tissue, specifically KRAS, TP53, BRAF, and PIK3CA. Median PFS and duration of response were not interpretable given that only 25% of patients came off trial for progression; all other patients withdrew to pursue surgery or liver embolization therapy, to receive therapy elsewhere, or due to toxicity associated with chemotherapy. The 1 year OS rate was 74%, and median OS has not been reached. The most common G3 or higher adverse events included neutropenia (31%), fatigue (11%), thromboembolism (9%), and cardiac events (9%). HCQ-attributable side effects included G1-3 insomnia (26%), G1-3 anxiety (20%), G1 visual disturbances (11%) and G3 allergy (3%). The majority of patients had increase in both LC3 and p62 in peripheral blood mononuclear cells and exhibited an increase in autophagosomes within the cytosol by electron microscopy. Conclusions: These data are promising and further evaluation in a randomized controlled trial is planned. Clinical trial information: NCT01206530.

A phase 1 study of osimertinib and bevacizumab as initial treatment for patients with EGFR-mutant lung cancers.

9033 Background: EGFR tyrosine kinase inhibitors (TKI) are the recommended first line treatment for EGFR-mutant lung cancers. Osimertinib, an EGFR TKI that inhibits both sensitizing EGFR mutations and EGFR T790M, is approved for use after progression on an EGFR TKI with evidence of EGFR T790M, and is currently being assessed as initial treatment for EGFR-mutant lung cancers. The addition of bevacizumab to erlotinib resulted in improved progression free survival (PFS) compared to erlotinib alone as initial treatment (16 vs 10 months, HR 0.41). This phase 1/2 study is assessing osimertinib and bevacizumab as initial treatment for patients with EGFR-mutant lung cancers. Methods: We evaluated toxicity and efficacy of osimertinib and bevacizumab as initial treatment for patients with advanced EGFR-mutant lung cancers. Using a 3+3 design, full doses of osimertinib (80mg PO daily) and bevacizumab (15mg/kg IV q3 weeks) were given, with a planned dose de-escalation (osimertinib 40mg PO daily) should grade 3 or greater toxicity be seen. Six patients must be treated without a dose-limiting toxicity (DLT) to determine the MTD. 43 additional patients will be treated at the MTD in the phase 2 study, with a primary endpoint of PFS at 12 months. Response was evaluated by RECIST 1.1. Results: From Sept 2016 to Jan 2017, 15 patients were enrolled. Median age: 63; Women 11; EGFR L858R = 8, Ex19del = 6, G709A/G719S = 1. After median duration of treatment of 2.7 months, no DLTs were seen in any patient. The MTD was determined to be osimertinib 80mg, bevacizumab 15mg/kg q3 weeks. In total, 15 patients are being treated at the MTD to date. Treatment-related adverse events (AE) were all grade 1-2, except for grade 3 hypertension. The most frequent treatment-related AEs (any grade) were rash (53%), diarrhea (40%), hypertension (33%), fatigue (20%), and itching (20%). All 15 patients continue on study. Conclusions: Combination osimertinib and bevacizumab is a tolerable first-line treatment for patients with EGFR-mutant lung cancers and the MTD is osimertinib 80mg and bevacizumab 15mg/kg q3 weeks. Assessment of efficacy with an endpoint of PFS at 12 months is ongoing. Supported by AstraZeneca (NCT02803203). Clinical trial information: NCT02803203.

Safety findings from FORWARD II: A Phase 1b study evaluating the folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC) mirvetuximab soravtansine (IMGN853) in combination with bevacizumab, carboplatin, pegylated liposomal doxorubicin (PLD), or pembrolizumab in patients (pts) with ovarian cancer.

5553 Background: FORWARD II is a phase 1b study of the FRα-targeting ADC, mirvetuximab soravtansine (IMGN853), in combination with bevacizumab (BEV), carboplatin, PLD, or pembrolizumab in adults with FRα-positive EOC, primary peritoneal, or fallopian tube tumors (NCT02606305). Methods: The escalation stage of this trial evaluated the safety and tolerability of IMGN853 as part of 4 combination regimens: IMGN853 + BEV; + carboplatin; + PLD; and + pembrolizumab. IMGN853 was administered in combination on Day 1 of a 21 (BEV or carboplatin) or 28-day cycle (PLD). Pembrolizumab escalation is continuing. The starting dose of IMGN853 was 5 mg/kg (adjusted ideal body weight, AIBW), one level lower than the recommended single agent phase 2 dose (RP2D; 6 mg/kg AIBW) defined in a first-in-human study (NCT01609556). Adverse events (AEs) were evaluated by CTCAE v4.0. Results: 46 pts enrolled in the first 3 cohorts. IMGN853 was escalated from 5 to 6 mg/kg. Carboplatin and PLD dosing were escalated from AUC4 to AUC5 and 30 to 40 mg/m2, respectively; BEV dosing remained constant at 15 mg/kg. Diarrhea, nausea, and fatigue were common across cohorts (all grades; 33-57%) and mostly low grade (i.e. ≤ 2), consistent with the IMGN853 safety profile from the earlier phase I monotherapy study. AEs of interest related to the combination agents were seen in each arm. For example, grade 1/2 proteinuria (36%) and grade 3 hypertension (21%) were only observed in the BEV combination. Thrombocytopenia (44%) and neutropenia (39%), grades 1-3, occurred most frequently in the carboplatin arm. Grade 3 anemia and vomiting (each 14%), as well as low grade (≤ 2) constipation (43%), were seen in the PLD cohort. Conclusions: The RP2D dose of IMGN853 was readily combined with the highest doses (as per protocol) of BEV, carboplatin, and PLD. The AE profiles for these combinations were manageable and as expected based on known profiles of each agent; importantly, no new safety signals were identified. Updated data from all 4 combination regimens will be presented. Clinical trial information: NCT02606305.

RNA-Seq to reveal mitochondrial gene fusions in breast cancer.

e13019 Background: Several mitochondrial DNA (mtDNA) mutations have been identified in various types of human cancer. While gene fusions encoded by the nuclear genome have an important role in tumorigenesis, the contribution of the mitochondrial genome to this process is unclear. mtDNA has limited protective mechanisms compared to that for nuclear DNA (nDNA), and hence more susceptible to genomic aberrations. Methods: We sequenced RNA from pre and post treatment breast cancer samples obtained from neoadjuvant clinical trials BrUOG 211A/211B. Seventy-three of these samples were considered baseline and 61 were from post-treatment samples, 54 samples at both time points. Patients were given a run-in dose of bevacizumab (B), nab- paclitaxel (N) or trastuzumab (T), followed by combination biologic/chemotherapy (HER2- with B/carboplatin/N; HER2+ with T/carboplatin/N). RNA was derived from biopsy pairs obtained pre/post 10-day exposure to run-in monotherapy. We used TopHat-Fusion and deFuse for fusion detection. Results: On average, in each patient 4.6 mtDNA gene fusions were detected at the baseline and 4 in the post treatment samples. In this cohort we detected in total 385 mtDNA fusions across the baseline and 344 across the post-treatment samples. A number of fusions had recurrently shown drastic increase from baseline to post-treatment, such as MT-ATP6:MT-ND2 ( N = 9), MT-ND6:MT-CO2 ( N = 6), MT-ND6:MT-CO1 ( N = 10), and MT-ND4:MT-ATP6 ( N = 9). We observe that some mitochondrial genes such as MT-ND6 have as many as 7 gene partners. MT-ND6 appeared in fusions that were most abundant among both baseline and post-treatment samples with MT:ND4 ( N = 39), MT:ND2 ( N = 37) and MD:ATP6 ( N = 36). Interestingly, gene fusions MT-ND6:J01415.25, MT-CYB:MT-ND2 and MT-ND6:MT-ND1 were observed respectively in 9, 5 and 4 baseline samples but not in their post treatment equivalent. Conclusions: While several studies have examined the presence of mtDNA mutations in breast cancer, the role of mitochondrial gene fusions is unknown in cancer. In our breast cancer cohort we observed quite a high number of mitochondrial fusions, and some of them seem to be recurrent in multiple samples. This could potentially have clinical implications as knowledge of fusions in solid tumours gains.

Topical Delivery of Anti-VEGF Drugs to the Ocular Posterior Segment Using Cell-Penetrating Peptides.

To evaluate the efficacy of anti-VEGF agents for treating choroidal neovascularization (CNV) when delivered topically using novel cell-penetrating peptides (CPPs) compared with delivery by intravitreal (ivit) injection. CPP toxicity was investigated in cell cultures. Ivit concentrations of ranibizumab and bevacizumab after topical administration were measured using ELISA. The biological efficacy of topical anti-VEGF + CPP complexes was compared with ivit anti-VEGF injections using an established model of CNV. CPPs were nontoxic in vitro. In vivo, after topical eye drop delivery, CPPs were present in the rat anterior chamber within 6 minutes. A single application of CPP + bevacizumab eye drop delivered clinically relevant concentrations of bevacizumab to the posterior chamber of the rat eye in vivo. Similarly, clinically relevant levels of CPP + ranibizumab and CPP + bevacizumab were detected in the porcine vitreous and retina ex vivo. In an established model of CNV, mice treated with either a single ivit injection of anti-VEGF, twice daily CPP + anti-VEGF eye drops or daily dexamethasone gavage for 10 days all had significantly reduced areas of CNV when compared with lasered eyes without treatment. CPPs are nontoxic to ocular cells and can be used to deliver therapeutically relevant doses of ranibizumab and bevacizumab by eye drop to the posterior segment of mouse, rat, and pig eyes. The CPP + anti-VEGF drug complexes were cleared from the retina within 24 hours, suggesting a daily eye drop dosing regimen. Daily, topically delivered anti-VEGF with CPP was as efficacious as a single ivit injection of anti-VEGF in reducing areas of CNV in vivo.

Effect of bevacizumab on acetic acid–induced ulcerative colitis in rats

BackgroundThe aim of this study was to examine the effect of intraperitoneally administered bevacizumab on colitis induced by acetic acid. MethodsAn experimental model of acetic acid–induced colitis was introduced in rats. After the induction of colitis, bevacizumab was administered intraperitoneally at two different daily doses of low (2.5 mg/kg) or high (5 mg/kg) concentration. Control groups were included for colitis and bevacizumab. After 7 d, the rats were sacrificed, and colonic tissues were harvested for macroscopic and microscopic examination of colonic damage. Tumor necrosis factor alpha, interleukin 1 beta (IL-1β), IL-6, myeloperoxidase, malondialdehyde, glutathione, and superoxidismutase values were measured biochemically. ResultsThere was no statistically significant macroscopic improvement in damage to the colon tissues (P > 0.05). The severity of inflammation was significantly reduced (0.98 ± 0.22) in the low-dose bevacizumab–treated rat group compared with the control group (P < 0.001). The decrease in the inflammation score in the high-dose bevacizumab–treated rat group was not statistically significant (1.40 ± 0.33). In addition, although there was no significant change in the myeloperoxidase levels biochemically, IL-6 and malondialdehyde levels decreased in the low-dose treatment group (P = 0.014, P = 0.002, respectively). A significant decrease was found at both treatment doses in IL-1β (P < 0.001, P = 0.010), tumor necrosis factor alpha (P < 0.001, P = 0.015), superoxidismutase (P = 0.046, P = 0.011), and glutathione (P = 0.012 and P < 0.001) levels. ConclusionsBoth treatment doses of bevacizumab were observed to have a protective effect in an experimental colitis model, and the dosage of 2.5 mg/kg bevacizumab was found to have a more prominent effect.

Apparent diffusion coefficient changes predict survival after intra-arterial bevacizumab treatment in recurrent glioblastoma

Superselective intra-arterial cerebral infusion (SIACI) of bevacizumab (BV) has emerged as a novel therapy in the treatment of recurrent glioblastoma (GB). This study assessed the use of apparent diffusion coefficient (ADC) in predicting length of survival after SIACI BV and overall survival in patients with recurrent GB. Sixty-five patients from a cohort enrolled in a phase I/II trial of SIACI BV for treatment of recurrent GB were retrospectively included in this analysis. MR imaging with a diffusion-weighted (DWI) sequence was performed before and after treatment. ROIs were manually delineated on ADC maps corresponding to the enhancing and non-enhancing portions of the tumor. Cox and logistic regression analyses were performed to determine which ADC values best predicted survival. The change in minimum ADC in the enhancing portion of the tumor after SIACI BV therapy was associated with an increased risk of death (hazard ratio=2.0, 95% confidence interval(CI) [1.04-3.79], p=0.038), adjusting for age, tumor size, BV dose, and prior IV BV treatments. Similarly, the change in ADC after SIACI BV therapy was associated with greater likelihood of surviving less than 1year after therapy (odds ratio=7.0, 95% CI [1.08-45.7], p=0.04). Having previously received IV BV was associated with increased risk of death (OR 18, 95% CI [1.8-180.0], p=0.014). In patients with recurrent GB treated with SIACI BV, the change in ADC value after treatment is predictive of overall survival.

A phase 1 study comparing the proposed biosimilar BS-503a with bevacizumab in healthy male volunteers.

This is a randomized, double‐blind, single‐dose, parallel group phase 1 study to assess pharmacokinetic similarity, safety, and tolerability of BS‐503a, a proposed bevacizumab biosimilar. A total of 114 male healthy subjects were randomized (1:1) to receive a single 3 mg/kg intravenous dose of either BS‐503a or bevacizumab (Avastin®). Pharmacokinetic (PK) blood samples were collected up to Day 78, and serum drug concentrations were measured using a validated enzyme‐linked immunosorbent assay. Pharmacokinetic similarity was evaluated using area under the serum concentration‐time curve from zero to infinity (AUC inf) as a primary PK parameter, and maximum serum concentration (C max) and area under the serum concentration‐time curve from zero to the last measurable time (AUC last) as secondary PK parameters. The 90% confidence intervals (CIs) of geometric mean ratio of AUC inf ranged 0.980–1.105, which met the predefined criteria of 0.80–1.25. The 90% CIs of geometric mean ratios for C max and AUC last were 1.009–1.125 and 0.982–1.096, respectively, falling into the same criteria. At least one drug‐related treatment emergent adverse event occurred in 18 and 21 subjects treated with BS‐503a and bevacizumab, respectively. The most common adverse events were headache, epistaxis, and rhinorrhea. Most adverse events were mild or moderate; however, one drug‐related serious adverse event of duodenal ulcer perforation was reported by a subject 47 days after treatment of BS‐503a. In conclusion, BS‐503a was demonstrated to have highly similar PK to bevacizumab and adverse events observed were consistent with those observed for bevacizumab.

Model driven optimization of antiangiogenics + cytotoxics combination: application to breast cancer mice treated with bevacizumab + paclitaxel doublet leads to reduced tumor growth and fewer metastasis.

Bevacizumab is the first-in-class antiangiogenic drug and is almost always administrated in combination with cytotoxics. Reports have shown that bevacizumab could induce a transient phase of vascular normalization, thus ensuring a better drug delivery when cytotoxics administration is adjuvant. However, determining the best sequence remains challenging. We have developed a mathematical model describing the impact of antiangiogenics on tumor vasculature. A 3.4 days gap between bevacizumab and paclitaxel was first proposed by our model. To test its relevance, 84 mice were orthotopically xenografted with human MDA-231Luc+ refractory breast cancer cells. Two sets of experiments were performed, based upon different bevacizumab dosing (10 or 20 mg/kg) and inter-cycle intervals (7 or 10 days), comprising several combinations with paclitaxel. Results showed that scheduling bevacizumab 3 days before paclitaxel improved antitumor efficacy (48% reduction in tumor size compared with concomitant dosing, p < 0.05) and reduced metastatic spreading. Additionally, bevacizumab alone could lead to more aggressive metastatic disease with shorter survival in animals. Our model was able to fit the experimental data and provided insights on the underlying dynamics of the vasculature's ability to deliver the cytotoxic agent. Final simulations suggested a new, data-informed optimal gap of 2.2 days. Our experimental data suggest that current concomitant dosing between bevacizumab and paclitaxel could be a sub-optimal strategy at bedside. In addition, this proof of concept study suggests that mathematical modelling could help to identify the optimal interval among a variety of possible alternate treatment modalities, thus refining the way experimental or clinical studies are conducted.

Influence of Bevacizumab on Blood-Brain Barrier Permeability and O-(2-18F-Fluoroethyl)-l-Tyrosine Uptake in Rat Gliomas.

Restoration of the blood-brain barrier (BBB) after antiangiogenic therapy of gliomas with bevacizumab may result in a decrease in contrast enhancement on MRI despite tumor progression. This so-called pseudoresponse is difficult to differentiate from a true tumor response with conventional MRI. Initial patient studies have indicated that PET using O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) may be helpful for solving this diagnostic problem. This study was performed to investigate the effects of bevacizumab on BBB permeability and 18F-FET uptake in a human xenograft model. Methods: Human U87 glioblastoma cells were implanted into the striatum of immunodeficient RNU rats. 18F-FET PET scans and ex vivo autoradiography were performed in animals receiving a single high dose of bevacizumab (45 mg/kg 2 d before PET; n = 9) or in animals receiving 2 lower doses (10 mg/kg 9 and 2 d before PET; n = 10) to evaluate short-term and long-term effects on the BBB, respectively, and in control animals without bevacizumab treatment (n = 8). Time-activity curves, slope, and tumor-to-brain ratios of 18F-FET uptake (18-61 min after injection) were evaluated using a volume-of-interest analysis. After PET scanning, Evans blue dye (EBD) was injected into animals, and cryosections of the brains were evaluated by autoradiography, by histology, and for EBD fluorescence to assess BBB permeability. Results: Compared with the control, short-term bevacizumab therapy resulted in a trend toward BBB restoration (P = 0.055) and long-term therapy resulted in a significant decrease (P = 0.004) in BBB permeability, as assessed by EBD fluorescence. In contrast, no significant differences in tumor-to-brain ratios or slope of 18F-FET uptake were observed in PET and autoradiography (P > 0.05). Conclusion:8F-FET uptake in glioblastomas seems to be largely independent of BBB permeability and reflects the viability of tumor tissue during antiangiogenic therapy more reliably than contrast-enhanced MRI.

A combination of low-dose bevacizumab and imatinib enhances vascular normalisation without inducing extracellular matrix deposition

Background:Vascular endothelial growth factor (VEGF)-targeting drugs normalise the tumour vasculature and improve access for chemotherapy. However, excessive VEGF inhibition fails to improve clinical outcome, and successive treatment cycles lead to incremental extracellular matrix (ECM) deposition, which limits perfusion and drug delivery. We show here, that low-dose VEGF inhibition augmented with PDGF-R inhibition leads to superior vascular normalisation without incremental ECM deposition thus maintaining access for therapy.Methods:Collagen IV expression was analysed in response to VEGF inhibition in liver metastasis of colorectal cancer (CRC) patients, in syngeneic (Panc02) and xenograft tumours of human colorectal cancer cells (LS174T). The xenograft tumours were treated with low (0.5 mg kg−1 body weight) or high (5 mg kg−1 body weight) doses of the anti-VEGF antibody bevacizumab with or without the tyrosine kinase inhibitor imatinib. Changes in tumour growth, and vascular parameters, including microvessel density, pericyte coverage, leakiness, hypoxia, perfusion, fraction of vessels with an open lumen, and type IV collagen deposition were compared.Results:ECM deposition was increased after standard VEGF inhibition in patients and tumour models. In contrast, treatment with low-dose bevacizumab and imatinib produced similar growth inhibition without inducing detrimental collagen IV deposition, leading to superior vascular normalisation, reduced leakiness, improved oxygenation, more open vessels that permit perfusion and access for therapy.Conclusions:Low-dose bevacizumab augmented by imatinib selects a mature, highly normalised and well perfused tumour vasculature without inducing incremental ECM deposition that normally limits the effectiveness of VEGF targeting drugs.

Inhibition of proliferation of retinal vascular endothelial cells more effectively than choroidal vascular endothelial cell proliferation by bevacizumab.

To evaluate the differential inhibitory effects of bevacizumab on cell proliferation of vascular endothelial growth factor (VEGF)-stimulated choroidal vascular endothelial cells (CVECs) and retinal vascular endothelial cells (RVECs) in vitro. VEGF (400 ng/mL) enriched CVECs and RVECs were treated with escalating doses of bevacizumab (0.1, 0.5, 1, 1.5 and 2 mg/mL). Cell proliferation changes were analyzed with WST-1 assay and trypan blue exclusion assay at 48, 72h and 1wk. Morphological changes were recorded with bright field microscopy. VEGF enriched RVECs showed significantly more decline of cell viability than CVECs after bevacizumab treatment. One week after treatment, RVEC cell proliferation decreased by 29.7%, 37.5%, 52.8%, 35.9% and 45.6% at 0.1, 0.5, 1.0, 1.5 and 2 mg/mL bevacizumab respectively compared to CVEC proliferation decrease of 4.1%, 7.7%, 2.4%, 4.1% and 17.7% (P<0.05) by WST-1 assay. Trypan blue exclusion assay also revealed similar decrease in RVEC proliferation of 20%, 60%, 73.3%, 80% and 93.3% compared to CVEC proliferation decrease of 4%, 12%, 22.9%, 16.7% and 22.2% respectively (P<0.05). The maximum differential effect between the two cell types was observed at bevacizumab doses of 1.0 and 1.5 mg/mL at all time points. RVECs were 22 fold more sensitive (P<0.01) compared to CVECs (52.8% vs 2.4%) at concentration of 1.0 mg/mL, and 8.7 fold more at 1.5 mg/mL (35.9% vs 4.1%) 1wk after treatment (P<0.05 respectively). VEGF-enriched RVECs are more susceptible to bevacizumab inhibition than CVECs at clinically used dosage of 1.25 mg and this differential sensitivity between two cell types should be taken into consideration in dosage selection.

A study on evaluation of bevacizumab in the management of diabetic retinopathy

Aims: The study stands to evaluate the usage of bevacizumab against diabetic retinal neovascularisation. Materials and Methods: The outcome measures of study include the determination of visual acuity and retinal cum macular thickness after bevacizumab administration. Twenty diabetic retinopathy patients were screened for bevacizumab administration and given either one or two doses of bevacizumab. Patient's visual acuity and optical tomography's results were analyzed to determine the vision, retinal, and macular thickness. Statistical Analysis Used: The numeric results were passed through analysis of variance, employing “Student's t-test” as posttest for statistically determining the numeric outcomes. Results: Within 1 month of bevacizumab administration visual acuity (distant vision, near vision, and pinhole vision) was improved to logarithm of the minimum angle of resolution (MAR) 0.63 ± 0.07 from 0.87 ± 0.12 of distant vision. Pinhole vision was improved to log MAR 0.37 ± 0.06 from 0.478 ± 0.07 and near vision was improve to log MAR 0.477 ± 0.071 from 0.528 ± 0.069, and retinal thickness was decreased to 336 ± 17.35 μm from 429 ± 30.20 μm. Mean macular thickness was improved to 363.75 ± 24.54 μm from 452.37 ± 30.99 μm. Conclusion: Hence, the off-label use of bevacizumab for the said treatment may be proven beneficial.

Chemotherapy in combination with bevacizumab in breast cancer. Results of the observational study in daily clinical practice

In metastatic breast cancer (MBC) the combination of Bevacizumab (Avastin) and chemotherapy (CT) failed to demonstrate an increase in overall survival with a significant improvement of the objective response rate and progression-free survival (PFS) in randomized trials of the 3d phase. Nevertheless, observational studies in the daily clinical practice for the use of Bevacizumab in MBC continue in the world. We present the results of our own observational study, which goal is to assess the efficacy and tolerability of Bevacizumab in combination with CT in patients with HER/2-negative metastatic and locally advanced breast cancer. The study included 34 patients with breast cancer (6-locally advanced, 28-metastatic) at the age of 29 to 66 years (mean – 49.5). Bevacizumab was administered at a dose of 7.5 to 15 mg/kg every 3 weeks in combination with CT. In total, the patients received 294 doses of Bevacizumab (median – 10). All patients with locally advanced breast cancer were operated on after the treatment completion, a pathologic complete response was registered in 33.3%. In MBC, the objective response was registered in 46,4%, tumor growth control in 89.3%, median PFS – 10 months. Typical for Bevacizumab adverse events, such as hypertension, proteinuria, were moderate and were met respectively in 14.7% and in 5.9% cases. In 1 (2.9%) patient the treatment was complicated by deep vein thrombosis and PE due to disease progression. Conclusion. Bevacizumab in combination with CT in breast cancer treatment can achieve high rates of objective response and PFS independent of the treatment line

SC26.02 Angiogenesis Inhibition in Lung Cancer: Recent Advances and Perspectives

SC26.02 Angiogenesis Inhibition in Lung Cancer: Recent Advances and Perspectives

Bevacizumab for the Treatment of Radiation-Induced Cerebral Necrosis: A Systematic Review of the Literature.

Radiation necrosis (RN) of brain tissue is a serious late complication of brain irradiation and recently bevacizumab has been suggested as treatment option of RN. There is a lack of data in the literature regarding the effectiveness of bevacizumab for the treatment of RN. The purpose of this review was to perform a comprehensive analysis of all reported cases using bevacizumab for the treatment of brain RN. In September 2016, we performed a comprehensive literature search of the following electronic databases: PubMed, Web of Science, Scopus and Cochrane Library. The research for the review was conducted using a combination of the keywords “radiation necrosis”, “radiotherapy” and “bevacizumab” alongside the fields comprising article title, abstract and keywords. Randomized trials, non-randomized trials, prospective studies, retrospective studies and single case reports were included in the review. Our research generated 21 studies and 125 cases where bevacizumab had been used for the treatment of RN. The median follow-up was 8 months and the most frequent bevacizumab dose used was 7.5 mg/kg for 2 weeks with a median of four cycles. Low-dose bevacizumab resulted in effectiveness with improvement in both clinical and radiographic response. The median decrease in T1 contrast enhancement and in T2/FLAIR signal abnormality was 64% and 60%, respectively. A reduction in steroidal therapy was observed in majority of patients treated. Based on the data of our review, bevacizumab appears to be a promising agent for the treatment of brain RN. Future prospective studies are required to evaluate the role of bevacizumab in RN and to define the optimal scheduling, dosage and duration of therapy.