Clinical evaluation of pediatric patients with recurrent respiratory papillomatosis.: A longitudinal study at a Saudi Arabian tertiary care center

OBJECTIVES

To study the clinical evaluation of recurrent respiratory papillomatosis (RRP) patients and the factors associated with the improvement in the Derkay's score as a measure of disease severity.

METHODS

A retrospective cohort that included all juvenile RRP patients who were admitted to King Abdulaziz University Hospital, Riyadh, Saudi Arabia, between September 2015 and June 2022 and underwent surgical debulking.

RESULTS

A total of 16 patients were eligible to join our study. Among them, 7 patients were males. Hoarseness of voice was the most frequent symptom. The median period of the follow-up was 56 months. Complete remission was achieved in 31.3%. The univariate linear regression model revealed that the cidofovir-treated patients had a significant reduction in the change value of Derkay's score compared to those without treatment (regression coefficient= -5.83, 95% confidence interval [CI]: [-11.5 to -0.143], p=0.045). Also, the increased first Derkay's score decreased the change value and subsequently increased the improvement chance of the disease (regression coefficient= -0.424, 95% CI: [-0.764 to -0.083], p=0.018). However, in the multivariate regression model, both variables showed non-significant results.

CONCLUSION

cidofovir treatment and higher Derkay's scores affected the disease improvement.

A case report describing the use of systemic bevacizumab in the treatment of recurrent respiratory papillomatosis with pulmonary involvement

Recurrent respiratory papillomatosis (RRP) is a rare disease characterized by recurrent papilloma along the aerodigestive tract. In this case, we describe a 16-year-old with longstanding laryngeal RRP secondary to vertical transmission of human papillomavirus (HPV) who presented with symptomatic pulmonary involvement and was successfully treated with systemic bevacizumab. The case describes the clinical and radiological improvement with therapy as well as the adverse effects that occurred and resolved with dose adjustments.

Long-Term Follow-up of Parenteral Bevacizumab In Patients with Recurrent Respiratory Papillomatosis

OBJECTIVE

The clinical course of recurrent respiratory papillomatosis (RRP) varies from spontaneous remission to severe airway obstruction with wide variability in recurrence. Standard treatment involves debulking to improve voice and/or breathing. Non-surgical therapies are emerging in hopes of non-operative disease control. This retrospective review analyzes long-term safety, efficacy, and durability of clinical control in the largest reported series of parenteral bevacizumab in adults with RRP.

METHODS

Twenty-three patients with known RRP who have been receiving off-label systemic bevacizumab were included. Dosage, infusion interval, number of cycles, debulking requirements, subjective outcomes, adverse events, and reasons for treatment termination were investigated.

RESULTS

Patients have been followed for an average of 791.43 (21-1468) days. The most common starting dosing regimen was 15 mg/kg at 3 weeks in 11 followed by 10 mg/kg at 6 weeks intervals in 6 individuals. Long-term maintenance dosage varied with the least intensive regimen being 10 mg/kg at 14-week intervals. Subjective improvement of voice and/or breathing was reported in 18/23 subjects. The median time for patients that needed a procedure after treatment was 634 days. Procedures after infusions decreased from 3.08 ± 2.48 procedures in the year prior to 0.52 ± 1.12 during systemic Bevacizumab, and to 0.86 ± 2.05 after stopping bevacizumab. Therapy termination occurred in 8 subjects where only 3 were due to adverse events.

CONCLUSION

Parenteral bevacizumab remains a well-tolerated treatment for patients with recalcitrant RRP. There appears to be a durable reduction in the frequency of debulking surgery requirements although on a maintenance regimen. Laryngoscope, 133:2725-2733, 2023.

Antiangiogenic drugs in combination with seaweed fucoidan: A mechanistic in vitro and in vivo study exploring the VEGF receptor and its downstream signaling molecules in hepatic cancer

Hepatocellular carcinoma (HCC) is one of the most common cancers reported worldwide with poor morbidity and high mortality rates. HCC is a very vascular solid tumour as angiogenesis is not only a key driver for tumour progression but also an exciting therapeutic target. Our research investigated the use of fucoidan, a sulfated polysaccharide readily abundant in edible seaweeds commonly consumed in Asian diet due to their extensive health benefits. Fucoidan was reported to possess a strong anti-cancer activity, but its anti-angiogenic potential is still to be fully unraveled. Our research investigated fucoidan in combination with sorafenib (an anti-VEGFR tyrosine kinase inhibitor) and Avastin^® (bevacizumab, an anti-VEGF monoclonal antibody) in HCC both in vitro and in vivo. In vitro on HUH-7 cells, fucoidan had a potent synergistic effect when combined with the anti-angiogenic drugs and significantly reduced HUH-7 cell viability in a dose dependent manner. Using the scratch wound assay to test cancer cell motility, sorafenib, A + F (Avastin and fucoidan) or S + F (sorafenib and fucoidan) treated cells consistently showed an unhealed wound and a significantly smaller %wound closure (50%-70%) versus untreated control (91%-100%) (p < 0.05, one-way ANOVA). Using RT-qPCR; fucoidan, sorafenib, A + F and S + F significantly reduced the expression of the pro-angiogenic PI3K/AKT/mTOR and KRAS/BRAF/MAPK pathways by up to 3 folds (p < 0.05, one-way ANOVA versus untreated control). While ELISA results revealed that in fucoidan, sorafenib, A + F and S + F treated cells, the protein levels of caspases 3, 8, and 9 was significantly increased especially in the S + F group showing 40- and 16-times higher caspase 3 and 8 protein levels, respectively (p < 0.05, one-way-ANOVA versus untreated control). Finally, in a DEN-HCC rat model, H&E staining revealed larger sections of apoptosis and necrosis in the tumour nodules of rats treated with the combination therapies and immunohistochemical analysis of the apoptotic marker caspase 3, the proliferation marker Ki67 and the marker for angiogenesis CD34 showed significant improvements when the combination therapies were used. Despite the promising findings reported herein that highlighted a promising chemomodulatory effect of fucoidan when combined with sorafenib and Avastin, further investigations are required to elucidate potential beneficial or adversary interactions between the tested agents.

Bevacizumab biosimilar LY01008 compared with bevacizumab (Avastin) as first-line treatment for Chinese patients with unresectable, metastatic, or recurrent non-squamous non-small-cell lung cancer: A multicenter, randomized, double-blinded, phase III trial

BACKGROUND

Previous studies have demonstrated the preclinical pharmacological and toxicological consistency, and clinical pharmacokinetic equivalence of bevacizumab biosimilar LY01008 with reference bevacizumab (Avastin). This randomized controlled trial aimed to compare the efficacy and safety of LY01008 with Avastin in first-line treatment of Chinese patients with advanced or recurrent non-squamous non-small cell lung cancer (NSCLC).

METHODS

Stage IIIB-IV NSCLC patients with evaluable lesions, good physical status, and adequate organ functions from 67 centers across China were randomized in a ratio of 1:1 to receive LY01008 or Avastin 15 mg/kg intravenously in combination with paclitaxel/carboplatin (combined treatment) for 4-6 cycles, followed by maintenance monotherapy with LY01008 until disease progression, intolerable toxicity, or death. The primary endpoint was objective response rate (ORR) in accordance with Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 confirmed by independent radiological review committees (IRRC). Secondary endpoints included disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. This study was registered in ClinicalTrials.gov (NCT03533127).

RESULTS

Between December 15th , 2017, and May 15th , 2019, a total of 649 patients were randomized to the LY01008 (n = 324) or Avastin (n = 325) group. As of September 25th , 2019 for primary endpoint analysis, 589 patients received ORR evaluation, with a median number of combined treatment cycles of 5 (range 1-6) and median duration of treatment of 3.0 (range 0.0-5.1) months. ORR of response-evaluable patients in the LY01008 and Avastin groups were 48.5% and 53.0%, respectively. The stratified ORR ratio was 0.91 (90% CI 0.80-1.04, within the prespecified equivalence margin of 0.75-1.33). Up to May 15th , 2020, with a median follow-up of 13.6 (range 0.8-28.4) months, no notable differences in DCR, median DoR, median PFS, median OS, and 1-year OS rate were observed between the LY01008 and Avastin groups. There were no clinically meaningful differences in safety and immunogenicity across treatment groups.

CONCLUSIONS

LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC. LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable, metastatic, or recurrent non-squamous NSCLC patients in the first-line setting.

Anti-VEGF Treatment in Corneal Diseases

BACKGROUND

Corneal neovascularization (CN) is a clue feature of different ocular pathological conditions and can lead to corneal edema and opacification with subsequent vision loss. Vascular endothelial growth factor (VEGF), which plays a key role in new vessels formation, proliferation and migration, was found to be up-regulated in these conditions. Nowadays, it is possible to downregulate the angiogenic process by using anti-VEGF agents administered by different routes.

OBJECTIVE

To evaluate the efficacy, safety and possible future directions of anti-VEGF agents used for the treatment of CNV owing to different aetiologies.

METHODS

A computerized search of articles dealing with the topic of anti-VEGF therapy in CN was conducted in PubMed, Scopus and Medline electronic databases. The following key phrases were used: anti-VEGF agents, corneal neovascularization, bevacizumab, ranibizumab, vascular endothelial growth factor, angiogenesis.

RESULTS

The use of anti-VEGF therapy in the treatment of CN reduced pathological vessel density without causing significant side effects. Various administration routes such as topical, subconjunctival and intrastromal ones are available, and the choice depends on patient and disease characteristics. Much more effectiveness is achieved in case of early administration before mature and wellestablished vessels take place. A combined approach between various drugs including anti-VEGF agents should be adopted in those cases at higher risk of neovascularization recurrence such as chronic long-standing diseases where ischemic and inflammatory stimuli are not definitively reversed.

CONCLUSION

The efficacy and safety of anti-VEGF agents support their adoption into the daily clinical practice for the management of CN.

Microporous Drug Delivery System for Sustained Anti-VEGF Delivery to the Eye

Purpose

To describe a novel microporous drug delivery system (DDS) for sustained anti- vascular endothelial growth factor (VEGF) delivery to the eye and to evaluate its efficacy in a corneal injury model.

Methods

A macro-porous DDS (1.5 × 1.5 × 4 mm) loaded with 2 mg of bevacizumab was implanted subconjunctivally in three Dutch-belted pigmented rabbits after corneal alkali injury (2N NaOH). Three rabbits received sham DDS. Animals were followed for three months and assessed in vivo and ex vivo for corneal neovascularization (NV), epithelial defect, stromal scarring, endothelial cell loss, and expression of angiogenic and inflammatory markers in the cornea and retina.

Results

Anti-VEGF DDS treatment led to complete inhibition of superior cornea NV and complete corneal re-epithelialization by day 58 whereas sham DDS resulted in severe cornea NV and persistent epithelial defect (9%∼12% of total cornea area) through the end of the study. Histologically, anti-VEGF DDS significantly reduced CD45⁺ and F4/80 CD11b⁺ cell accumulation (79%, P < 0.05) in the cornea, ameliorated tumor necrosis factor–α expression (90%, P < 0.05), reduced corneal stromal scarring and prevented corneal endothelial cell loss, as compared to sham DDS. Moreover, anti-VEGF DDS achieved retinal penetration and reduction in retinal VEGF levels at 3 months.

Conclusions

Use of subconjunctival anti-VEGF DDS suppresses cornea NV, inflammation, stromal scarring, prevents endothelial cell loss, and abrogates retinal VEGF upregulation in a rabbit corneal alkali burn model. Moreover, it delivers anti-VEGF antibodies to the retina for three months. This delivery platform could enable antibody therapy of other corneal and retinal vascular pathologies.

Translational Relevance

We describe a method for sustained anti-VEGF delivery to the eye for the treatment of ocular injuries.

Intralesional Bevacizumab for the Treatment of Recurrent Sinonasal Hemangioma

INTRODUCTION:

Sinonasal hemangioma is a rare benign tumor of vascular endothelial cells. The pathogenesis is closely linked to abnormalities in the vascular endothelial growth factor signaling pathway. Multiple treatment modalities are available, though wide local excision remains the preferred treatment. Bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, has known efficacy against hemangiomas, though there are no cases of sinonasal hemangiomas managed with bevacizumab.

METHODS:

Case report.

RESULTS:

The authors review the case of a 67-year-old man with a left-sided nasal hemangioma originating from the nasal septum. He presented with progressive left nasal obstruction and recurrent epistaxis. At the time of his presentation, the lesion had recurred after 1 excision/polypectomy at an outside institution. He then underwent revision surgery via wide local excision and septoplasty. After tumor recurrence following the revision surgery, the hemangioma was noted to recur on 1 year postoperative surveillance nasal endoscopy. In-office intralesional injection of 50 mg bevacizumab was then performed under endoscopic visualization. No improvement in the tumor size was noted at 2 months after injection, with the tumor measuring 1.5 cm. At the 10-month surveillance clinical visit following injection, the tumor had dramatically involuted to 3 mm in greatest dimension. The patient reported complete resolution of his primary symptoms of epistaxis and nasal obstruction.

CONCLUSIONS:

This report demonstrates the first reported successful treatment of a sinonasal hemangioma with intralesional bevacizumab. Intralesional bevacizumab confers an additional option for adjuvant treatment of sinonasal hemangiomas. Further evaluation of intralesional bevacizumab in the treatment of these tumors is warranted.

Progression-free survival as a surrogate endpoint of overall survival in patients with metastatic colorectal cancer

Background

In many clinical trials designed to assess the efficacy of anticancer treatments, overall survival (OS) is often used as a primary endpoint despite its several points of weakness.

Methods

This study evaluated the role of progression-free survival (PFS) in the first three lines of treatment as a potential surrogate endpoint of OS in patients with metastatic colorectal cancer (MCRC). One hundred and twenty patients with MCRC were enrolled in this study. The median PFS of the first-, second-, and third-lines of treatment and the OS were evaluated. The correlation between the time to progression and the OS was analyzed. The median PFS of the three lines of treatment were 8.5, 5, and 3 months, respectively.

Results

The median OS was 32.4 months. A modest correlation was found between the PFS to the first-line treatment with Folfox–avastin and OS. Similar data were obtained with the second-line treatment. However, no correlation was found between the PFS and OS during the third-line treatment. The regression analysis revealed that PFS is predictive of OS.

Conclusion

In brief, the PFS of the first- and second-lines of treatment could be a good candidate as a surrogate endpoint of OS in patients with MCRC.

Combination use of paclitaxel and avastin enhances treatment effect for the NSCLC patients with malignant pleural effusion

The current study is conducted to investigate efficacy of the chemotherapy drug paclitaxel in combination with Avastin (Roche Diagnostics GmbH., Mannheim, Germany) (antiangiogenic agent) in treatment of malignant pleural effusions (MPEs).Twenty-four patients with non-small cell lung cancer were randomly assigned for 2 treatment approaches. Ten patients received paclitaxel (175 mg/m) alone, and 14 patients took a combination therapy of paclitaxel and Avastin (5 mg/kg). Efficacy of the treatment approaches in the patients was validated with the change in the MPE volume. Pharmacokinetic (PK) profile and urinary excretion rate of paclitaxel were analyzed with serum vascular endothelial growth factor (VEGF) level, and adverse events were examined as well.The combination therapy reduced the MPE level with a successful rate of 29% and a survival rate of 25% over the single paclitaxel treatment in the study cohort (both P < 0.05). PKs for the combined treatment displayed a rapid distribution of the anticancer drug paclitaxel with an obvious increase in its elimination half-life in the pleural fluid (both P < 0.01). Mean residence time of paclitaxel increased in the presence of Avastin (P < 0.01). Serum VEGF levels significantly reduced in the Avastin-treated patients as compared to the paclitaxel-treated ones (P < 0.01). The urinary excretion rate was similar in the study cohort. Incidence of adverse events for the 2 treatment approaches was similar in the patients.Intervention of Avastin enhances potency of paclitaxel in treatment of MPEs with the increased survival rate of the patients through inhibiting VEGF production and prolonging time of ongoing interaction between the chemotherapy drug and the tumor tissues.

Effects of anti-vascular endothelial growth factor monoclonal antibody (bevacizumab) on lens epithelial cells

The molecular and cellular effects of anti-vascular endothelial growth factor monoclonal antibody (bevacizumab) on lens epithelial cells (LECs) were examined using both an immortalized human lens epithelial cell line and a porcine capsular bag model. After treatment with various concentrations of bevacizumab, cell viability and proliferation patterns were evaluated using the water-soluble tetrazolium salt assay and 5-bromo-2′-deoxyuridine enzyme-linked immunosorbent assay, respectively. The scratch assay and Western blot analysis were employed to validate the cell migration pattern and altered expression levels of signaling molecules related to the epithelial–mesenchymal transition (EMT). Application of bevacizumab induced a range of altered cellular events in a concentration-dependent manner. A 0.1–2 mg/mL concentration demonstrated dose-dependent increase in proliferation and viability of LECs. However, 4 mg/mL decreased cell proliferation and viability. Cell migrations displayed dose-dependent retardation from 0.1 mg/mL bevacizumab treatment. Transforming growth factor-β2 expression was markedly increased in a dose-dependent manner, and α-smooth muscle actin, matrix metalloproteinase-9, and vimentin expression levels showed dose-dependent changes in a B3 cell line. Microscopic observation of porcine capsular bag revealed changes in cellular morphology and a decline in cell density compared to the control after 2 mg/mL treatment. The central aspect of posterior capsule showed delayed confluence, and the factors related to EMT revealed similar expression patterns to those identified in the cell line. Based on these results, bevacizumab modulates the proliferation and viability of LECs and induces morphological alterations through the modulation of expression patterns of specific factors related to the EMT.

Effect of YangZheng XiaoJi Extract, DME-25, on Endothelial Cells and their Response to Avastin

BACKGROUND

Angiogenesis is a cellular process that has been identified as a key target for therapy in solid cancer. However, over the course of anti-angiogenic therapies, cancer cells acquire resistance to these therapies after an initial period of success. DME-25 is an extract from Yang Zheng Xiao Ji, a traditional Chinese medicine that has been reported to benefit patients with cancer by alleviating chemotherapy-associated symptoms and possibly inhibiting key cancer cell traits. This study aimed to explore if DME-25 on its own and in combination with avastin affected endothelial cell behaviour in vitro in the presence of hypoxic lung cancer-conditioned medium (CM).

MATERIALS AND METHODS

Two lung cancer cell lines, A549 and SK-MES-1, were exposed to hypoxic conditions (O2 ≤1%) for 4 h, after which CM, and RNA were collected. Transcript expression of several influential angiogenic markers in lung cancer cells were assessed following hypoxic/normoxic conditions. Lung cancer CM was added in combination with avastin and DME-25, before or after vascular endothelial growth factor (VEGF) depletion, to endothelial cells (HECV) and cell migration and microtubule formation were assessed in vitro.

RESULTS

HECV cell migration was reduced in the presence of avastin, although less efficiently in the presence of lung cancer CM. A combination of DME-25 and avastin with lung cancer CM significantly reduced HECV cell migration irrespective of culture under hypoxia or normoxia. Depletion of VEGF from the CM reduced the inhibitory capacity of avastin, however, it appeared to have little impact on the anti-angiogenic effects of DME-25.

CONCLUSION

DME-25 inhibits tubule formation irrespectively of the factors secreted by normoxic or hypoxic lung cancer cell CM depleted of VEGF.

Injectable Chemically Crosslinked Hydrogel for the Controlled Release of Bevacizumab in Vitreous: A 6-Month In Vivo Study

PURPOSE

To evaluate the biocompatibility and 6-month in vivo release of bevacizumab from a hyaluronic acid/dextran-based in situ hydrogel after intravitreal injection in rabbit eye.

METHODS

The in situ hydrogel was formed by the catalyst-free chemical crosslinking between vinylsulfone functionalized hyaluronic acid (HA-VS) and thiolated dextran (Dex-SH) at physiological condition. The pH 7.4 buffered mixture containing HA-VS, Dex-SH, and bevacizumab were injected into the vitreous of rabbit eyes by a 30-G needle. The biocompatibility was evaluated by intraocular pressure measurement, binocular indirect ophthalmoscope (BIO), full-field electroretinogram (ERG), and histology. The concentrations of both total and active bevacizumab in rabbit vitreous were determined by enzyme-linked immunosorbent assay. The concentration of bevacizumab in rabbit vitreous after bolus injection was simulated by one-compartment first order elimination model.

RESULTS

A transparent gel was seen in the vitreous after injection. BIO images, ERG, and histology showed that the gel does not induce hemorrhage, retinal detachment, inflammation, or other gross pathological changes in rabbit eyes after injection. While the bolus intravitreal injected bevacizumab follows the first order elimination kinetics in rabbit eye, the in situ gel formation was able to prolong the retention of bevacizumab in rabbit eye at therapeutic relevant concentration for at least 6 months. The concentration of bevacizumab 6 months after injection was about 10⁷ times higher than bolus injection.

CONCLUSIONS

The new in situ hydrogel formulation of bevacizumab was biocompatible and able to prolong the retention of drug in rabbit eyes in vivo at therapeutic relevant concentration for at least 6 months.

TRANSLATIONAL RELEVANCE

Although proven to be effective, monthly intravitreal injection of bevacizumab or other protein drugs may cause various complications. Extending the residence time of protein therapeutics in the eye can reduce the injection frequency, its associated complications, and treatment cost, which will be beneficial to both the patients and doctors. In this study, we showed that the in situ hydrogel-based controlled release system is a feasible option to tackle this problem.

Intranasal submucosal bevacizumab for epistaxis in hereditary hemorrhagic telangiectasia: a double-blind, randomized, placebo-controlled trial

BACKGROUND

The purpose of this study was to investigate the efficacy of bevacizumab ("Avastin") for the treatment of epistaxis in hereditary hemorrhagic telangiectasia (HHT).

METHODS

In this double blind, placebo controlled trial, 15 adult patients with HHT with a minimum of 2 epistaxis episodes per week were randomized. A history of thromboembolic events or recent or planned surgery led to exclusion. Patients received a single intranasal submucosal injection (10 mL) of 100 mg bevacizumab or placebo. The primary outcome was the relative reduction of average daily epistaxis visual analog score (VAS).

RESULTS

Average daily posttreatment VAS scores decreased by 27% in the bevacizumab group and by 3% in the placebo group (p = .57). The reduction in HHT epistaxis severity scores was -0.61 greater in the bevacizumab group compared to the placebo group (p = .34).

CONCLUSION

Results show a trend toward reduced epistaxis with bevacizumab. This further supports the use of bevacizumab in HHT. Clincial Trials. gov number: NCT01314274

Topical delivery of Avastin to the posterior segment of the eye in vivo using annexin A5-associated liposomes

Effective delivery to the retina is presently one of the most challenging areas in drug development in ophthalmology, due to anatomical barriers preventing entry of therapeutic substances. Intraocular injection is presently the only route of administration for large protein therapeutics, including the anti-Vascular Endothelial Growth Factors Lucentis (ranibizumab) and Avastin (bevacizumab). Anti-VEGFs have revolutionised the management of age-related macular degeneration and have increasing indications for use as sight-saving therapies in diabetes and retinal vascular disease. Considerable resources have been allocated to develop non-invasive ocular drug delivery systems. It has been suggested that the anionic phospholipid binding protein annexin A5, may have a role in drug delivery. In the present study we demonstrate, using a combination of in vitro and in vivo assays, that the presence of annexin A5 can significantly enhance uptake and transcytosis of liposomal drug carrier systems across corneal epithelial barriers. This system is employed to deliver physiologically significant concentrations of Avastin to the posterior of the rat eye (127 ng/g) and rabbit retina (18 ng/g) after topical application. Our observations provide evidence to suggest annexin A5 mediated endocytosis can enhance the delivery of associated lipidic drug delivery vehicles across biological barriers, which may have therapeutic implications.

Predictors of visual outcome in eyes with choroidal neovascularization secondary to age related macular degeneration treated with intravitreal bevacizumab monotherapy

AIM

To evaluate the predictors of visual improvement in eyes with naive choroidal neovascularization secondary to age-related macular degeneration (CNV -AMD) treated with intravitreal bevacizumab (IVB) monotherapy.

METHODS

Fifty eyes with naive CNV- AMD with pretreatment best-corrected visual acuity (BCVA) better than 20/200 and treated with IVB monotherapy were evaluated. Several variables including age, sex, pre-treatment BCVA, CNV type and lesion size on fluorescein angiogram as well as SD-OCT parameters including pre-treatment central macular thickness (CMT), inner-segment/outer-segment (IS/OS) junction integrity, and external limiting membrane (ELM) integrity were analyzed to predict visual outcome.

RESULTS

On univariate regression, pretreatment ELM damage was associated with less visual improvement after treatment (P=0.0145). However, ELM damage predicted only 10% of the visual outcome. On multivariate regression, pretreatment BCVA, IS/OS junction, and ELM integrity on SD-OCT were the significant predictors for the treatment effect and together predicted 37% of visual improvement.

CONCLUSION

Pretreatment BCVA, ELM and IS/OS junction integrity on SD-OCT are of significant value in predicting the visual improvement in naive wet AMD patients treated with IVB monotherapy.

Posterior vitreous detachment with microplasmin alters the retinal penetration of intravitreal bevacizumab (Avastin) in rabbit eyes

PURPOSE

Intravitreal bevacizumab (BV) (Avastin, Genentech Inc., South San Francisco, CA) is frequently used for the treatment of age-related macular degeneration. Previous studies have demonstrated full-thickness retinal penetration. Intravitreal recombinant microplasmin (MP) has been shown to successfully induce a posterior vitreous detachment (PVD) and vitreous liquefaction in animals. It has been suggested that a PVD may alter the retinal penetration of molecules in the vitreous cavity. The aim of this study was to compare BV retinal penetration in rabbit eyes with and without an MP-induced PVD.

METHODS

Twelve adult rabbits were injected with 0.1 mL (0.4 mg) of MP into the vitreous cavity of 1 eye. One week later, the rabbits were injected with 0.05 mL (1.25 mg) of BV into both eyes. Both eyes of 3 rabbits were harvested at 6 hours, 12 hours, 24 hours, and 72 hours after the BV injection. Frozen retinal cross sections were prepared, and BV retinal penetration was evaluated with immunohistochemistry using a fluorescence-labeled antibody against BV. Two eyes from one rabbit were not injected with either agent and used as controls to compare the background autofluorescence. Peripapillary retinal sections were recorded with a digital camera, and intraretinal BV fluorescence-labeled antibody was measured by qualitative photographic interpretation. Two additional rabbits received an intravitreal injection of 0.1 mL of MP in 1 eye. One week later, both eyes from each rabbit were enucleated, and frozen retinal sections were prepared and analyzed with light microscopy to evaluate histologic damage.

RESULTS

Full-thickness BV retinal penetration was observed throughout the retina in both eyes of each rabbit. All the MP-injected eyes exhibited increased antibody labeling in retinas evaluated at 6 hours, 12 hours, and 24 hours after BV injection when compared with the contralateral non-MP-injected eyes. By 3 days after BV injection, all eyes demonstrated decreased antibody labeling compared with earlier periods. At 3 days, 1 rabbit showed increased antibody labeling in the retina of the non-MP-injected eye compared with the contralateral MP-injected eye, and 2 rabbits exhibited similar antibody labeling in both eyes. When compared with control eyes, light microscopy demonstrated normal retinal histologic findings in eyes injected only with MP.

CONCLUSION

Increased BV retinal penetration is observed initially in eyes with an MP-induced PVD, and the mechanism is likely multifactorial. By 3 days, retinal penetration is similar in eyes with and without a PVD. Although it is difficult to directly extrapolate to humans, our study suggests that a PVD may alter the retinal penetration of BV.

Long-term use of intravitreal bevacizumab (avastin) for the treatment of von hippel-lindau associated retinal hemangioblastomas

Retinal hemangioblastomas are the most common manifestation of Von Hippel-Lindau (VHL) disease [1-3]. While peripheral retinal hemangioblastomas may be treated by thermal laser treatment or cryotherapy, optic nerve and macular lesions are more difficult to treat [4, 5]. Based on the theoretical benefit of administering anti-VEGF treatment, intra-vitreally administered bevacizumab (Avastin, a general pan-VEGF inhibitor) is attractive [6, 7].

Several short-term case series using ranibizumab (Lucentis, mAb fragment of bevacizumab with stronger affinity for VEGF-A) have shown it has promising but minimal success on most VHL-related hemangioblastomas [8, 9]. A comprehensive study by Wong et al. examined 5 patients over a period up to 61 weeks (47 ± 14 weeks) while Michels et al. examined one patient over a period of 4 months. Due to the short-term nature of these studies, we attempted long-term bevacizumab treatment over 60 months in a monocular subject with progressive visual loss due to a VHL associated macular and optic nerve hemangioblastoma. Over the treatment regimen of 15 injections, visual acuity improved 25 letters, OCT thickness improved from 646 um to 424 um, and structural lesions stabilized while exudates and edema resolved.

Update and developments in the treatment of glioblastoma multiforme - focus on bevacizumab

Glioblastoma is the most common primary brain tumor with a relatively poor prognosis. This article reviews the current standard therapy and discusses new developments in treatment of this disease. Surgical resection followed by radiation and chemotherapy has proven to be the most effective initial therapy. Recent advancement in molecular targeted therapies has led to the Food and Drug Administration (FDA) approval of bevacizumab in the setting of recurrent glioblastoma. The molecular pathways of glioblastoma growth are highlighted in this review. While numerous molecular targets are currently being intensely investigated, vascular endothelial growth factor (VEGF) receptor targeted therapy has been the only one to have shown clinical effect. The role of bevacizumab in this context provides a dynamic breakthrough in cancer therapy. Clinical trials have demonstrated significantly increased overall survival and six month progression free survival (PFS) in recurrent glioblastoma treated with bevacizumab alone or in combination with irinotecan. The use of this agent has also dramatically changed the imaging characteristics of glioblastoma. The anti-angiogenesis effects of bevacizumab have complicated the criterion for determining tumor growth. This may lead to redefinition of progressive disease based on non-invasive monitoring.

Therapeutic antibodies: current state and future trends--is a paradigm change coming soon?

Antibody-based therapeutics currently enjoy unprecedented success, growth in research and revenues, and recognition of their potential. It appears that the promise of the "magic bullet" has largely been realized. There are currently 22 monoclonal antibodies (mAbs) approved by the United States Food and Drug Administration (FDA) for clinical use and hundreds are in clinical trials for treatment of various diseases including cancers, immune disorders, and infections. The revenues from the top five therapeutic antibodies (Rituxan, Remicade, Herceptin, Humira, and Avastin) nearly doubled from $6.4 billion in 2004 to $11.7 billion in 2006. During the last several years major pharmaceutical companies raced to acquire antibody companies, with a recent example of MedImmune being purchased for $15.6 billion by AstraZeneca. These therapeutic and business successes reflect the major advances in antibody engineering which have resulted in the generation of safe, specific, high-affinity, and non-immunogenic antibodies during the last three decades. Currently, second and third generations of antibodies are under development, mostly to improve already existing antibody specificities. However, although the refinement of already known methodologies is certainly of great importance for potential clinical use, there are no conceptually new developments in the last decade comparable, for example, to the development of antibody libraries, phage display, domain antibodies (dAbs), and antibody humanization to name a few. A fundamental question is then whether there will be another change in the paradigm of research as happened 1-2 decades ago or the current trend of gradual improvement of already developed methodologies and therapeutic antibodies will continue. Although any prediction could prove incorrect, it appears that conceptually new methodologies are needed to overcome the fundamental problems of drug (antibody) resistance due to genetic or/and epigenetic alterations in cancer and chronic infections, as well as problems related to access to targets and complexity of biological systems. If new methodologies are not developed, it is likely that gradual saturation will occur in the pipeline of conceptually new antibody therapeutics. In this scenario we will witness an increase in combination of targets and antibodies, and further attempts to personalize targeted treatments by using appropriate biomarkers as well as to develop novel scaffolds with properties that are superior to those of the antibodies now in clinical use.