Preclinical evaluation of ADVM-062, a novel intravitreal gene therapy vector for the treatment of blue cone monochromacy

Blue cone monochromacy (BCM) is a rare X-linked retinal disease characterized by the absence of L- and M-opsin in cone photoreceptors, considered a potential gene therapy candidate. However, most experimental ocular gene therapies utilize subretinal vector injection which would pose a risk to the fragile central retinal structure of BCM patients. Here we describe the use of ADVM-062, a vector optimized for cone-specific expression of human L-opsin and administered using a single intravitreal (IVT) injection. Pharmacological activity of ADVM-062 was established in gerbils, whose cone-rich retina naturally lacks L-opsin. A single IVT administration dose of ADVM-062 effectively transduced gerbil cone photoreceptors and produced a de novo response to long-wavelength stimuli. To identify potential first-in-human doses we evaluated ADVM-062 in non-human primates. Cone-specific expression of ADVM-062 in primates was confirmed using ADVM-062.myc, a vector engineered with the same regulatory elements as ADVM-062. Enumeration of human OPN1LW.myc-positive cones demonstrated that doses ≥3 × 1010 vg/eye resulted in transduction of 18%-85% of foveal cones. A Good Laboratory Practice (GLP) toxicology study established that IVT administration of ADVM-062 was well tolerated at doses that could potentially achieve clinically meaningful effect, thus supporting the potential of ADVM-062 as a one-time IVT gene therapy for BCM.

Abstract 3966: Mining the cancer immuno-responsome: The identification of functional antitumor antibodies from patients receiving checkpoint inhibitors

Background: The role of B cells and antibodies in anticancer immune responses may correlate with improved prognosis in several types of cancer. Indeed, tumor-reactive antibodies are detected in the blood of cancer patients, tumor-infiltrating B cells have been shown to produce tumor-reactive antibodies, and tumor-reactive antibodies can cause tumor regression in several mouse models. Taken together, these observations support further identification, isolation and characterization of antitumor antibodies from patients demonstrating effective anticancer responses and defining the cognate targets and mechanisms whereby they contribute to tumor control.

Methods: We identified cohorts of patients with nonprogressing metastatic cancer who had received checkpoint immunotherapy and isolated their circulating plasmablasts. Antibody heavy and light chain paired sequences were obtained from individual cells using Atreca's Immune Repertoire Capture (IRCTM) technology. The expressed antibodies were then analyzed for their ability to bind to tumor cells as well as tumor tissue and their ability to mediate antitumor activity was explored in syngeneic mouse tumor models.

Results: Elevated plasmablast levels were observed in individuals with nonprogressing metastatic cancer, and analysis of plasmablast antibody sequences revealed clonal families of B cells that persisted over time with hallmarks of affinity maturation and class switching. We also identified antibody sequences with features common to more than one patient, consistent with convergent antibody selection. In particular, one antibody (AB-213) isolated from a NSCLC patient was found to demonstrate binding to unrelated human tumors as well as the mouse EMT6 tumor. When AB-213 was expressed with a mouse IgG2a constant region the chimeric antibody showed efficacy in vivo by reducing tumor volume and increasing survival in Balb/c mice harboring the syngeneic EMT6 model. Antitumor activity of the chimeric antibody was observed to be dose-dependent when administered as monotherapy or in combination with checkpoint inhibitors. We feel, based on these data, AB-213 could become a very important clinical therapeutic.

Citation Format: Gilson Baia, Amy Manning-Bog, Alexander Scholz, Jeff DeFalco, Michael Harbell, Danhui Zhang, Felix Chu, Beatriz Millare, May Sumi, Patricia Zuno, Judevin Lugar Sapugay, Dongkyoon Kim, Yvonne Leung, Shuwei Jiang, Xiaobin Tang, Kevin Williamson, Xiaomu Chen, Sean Carroll, Christine Dowd, Ish Dhawan, Jonathan Benjamin, Gregg Espiritu Santo, Nicole Haaser, Ngan Nguyen, Eldar Giladi, David Minor, Yann Chong Tan, Jeremy B. Sokolove, Lawrence Steinman, Tito Serafini, Guy Cavet, Norman M. Greenberg, Jacob Glanville, Wayne Volkmuth, Daniel E. Emerling, William H. Robinson. Mining the cancer immuno-responsome: The identification of functional antitumor antibodies from patients receiving checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3966.

Non-progressing cancer patients have persistent B cell responses expressing shared antibody paratopes that target public tumor antigens

There is significant debate regarding whether B cells and their antibodies contribute to effective anti-cancer immune responses. Here we show that patients with metastatic but non-progressing melanoma, lung adenocarcinoma, or renal cell carcinoma exhibited increased levels of blood plasmablasts. We used a cell-barcoding technology to sequence their plasmablast antibody repertoires, revealing clonal families of affinity matured B cells that exhibit progressive class switching and persistence over time. Anti-CTLA4 and other treatments were associated with further increases in somatic hypermutation and clonal family size. Recombinant antibodies from clonal families bound non-autologous tumor tissue and cell lines, and families possessing immunoglobulin paratope sequence motifs shared across patients exhibited increased rates of binding. We identified antibodies that caused regression of, and durable immunity toward, heterologous syngeneic tumors in mice. Our findings demonstrate convergent functional anti-tumor antibody responses targeting public tumor antigens, and provide an approach to identify antibodies with diagnostic or therapeutic utility.

Five year results of LINAC radiosurgery for arteriovenous malformations: outcome for large AVMS

PURPOSE

For radiosurgery of large arteriovenous malformations (AVMs), the optimal relationship of dose and volume to obliteration, complications, and hemorrhage is not well defined. Multivariate analysis was performed to assess the relationship of multiple AVM and treatment factors to the outcome of AVMs significantly larger than previously reported in the literature.

METHODS AND MATERIALS

73 patients with intracranial AVMs underwent LINAC radiosurgery. Over 50% of the AVMs were larger than 3 cm in diameter and the median and mean treatment volumes were 8.4 cc and 15.3 cc, respectively (range 0.4-143.4 cc). Minimum AVM treatment doses varied between 1000-2200 cGy (median: 1600 cGy).

RESULTS

The obliteration rates for treatment volumes < 4 cc, 4-13.9 cc, and > or = 14 cc were 67%, 58%, and 23%, respectively. AVM obliteration was significantly associated with higher minimum treatment dose and negatively associated with a history of prior embolization with particulate materials. No AVM receiving < 1400 cGy was obliterated. The incidence of post-radiosurgical imaging abnormalities and clinical complications rose with increasing treatment volume. For treatment volumes > 14 cc receiving > or = 1600 cGy, the incidence of post-radiosurgical MRI T2 abnormalities was 72% and the incidence of radiation necrosis requiring resection was 22%. The rate of post-radiosurgical hemorrhage was 2.7% per person-year for AVMs with treatment volumes < 14 cc and 7.5% per person-year for AVMs > or = 14 cc.

CONCLUSION

As AVM size increases, the dose-volume range for the optimal balance between successful obliteration and the risk of complications and post-radiosurgical hemorrhage narrows.

Embolization of neurosurgical lesions involving the ophthalmic artery

OBJECTIVE

A number of anteriorly located cranial base and extracranial lesions receive their vascular supply wholly or in part from the ophthalmic artery, and embolization of the ophthalmic artery can be helpful in the management of these lesions, either as the primary treatment or as an adjunct to surgery. We present situations in which the embolization of lesions involving the ophthalmic artery was performed to effect a partial or total cure of the lesion.

METHODS

Twelve patients underwent a total of 15 embolization attempts on lesions involving the ophthalmic artery. Four patients had arteriovenous malformations of the orbit, four had dural arteriovenous fistulae, two had orbital meningiomas, one had a planum sphenoidale meningioma, and one had a juvenile nasal angiofibroma. In each case, a Tracker No. 18 microcatheter (Target Therapeutics, Inc., Fremont, CA) was navigated into the ophthalmic artery using a steerable guidewire and digital road mapping. Embolic agents included polyvinyl alcohol particles ranging from 350 to 1500 microm in diameter, 2-mm platinum microcoils, and n-butyl-cyanoacrylate. In 12 of 15 cases, lidocaine and amytal provocation tests were conducted before any attempt at embolization to assess the role of the ophthalmic artery in vision.

RESULTS

Embolization was successfully performed in the 14 situations in which it was attempted. Positive results of two lidocaine/amytal tests were noted. In one case, embolization was not attempted. In the other case, a larger caliber embolic agent (2-mm platinum coils) was used. A single transient decrease in visual acuity lasting 4 days was the only embolization-related complication.

CONCLUSION

Proper case selection, judicious use of embolic agents, and use of provocative testing can result in safe embolization of lesions supplied by the ophthalmic artery.

Mathematical cognitive style and arithmetic sign comprehension: a study of EEG alpha and theta activity

The localization of arithmetic sign comprehension was investigated using EEG spectral parameters as indicators of cortical engagement. Right-handed male subjects were selected on the basis of scores on the Mathematics Cognitive Style Survey and assigned to 2 groups, a 'left hemisphere oriented (LHO)' (N = 9) and 'right hemisphere oriented (RHO)' (N = 9) group. Subjects were presented with 4 conditions, a motoric baseline condition, two arithmetic fact retrieval tasks employing either a sign operator or verbal operator and a sign comprehension task which required subjects to fill in a missing sign (e.g. 6 ? 4 = 24). Both across subject correlational analysis of EEG alpha 1 asymmetry and performance as well as within subject analysis of condition means indicated a somewhat unique contribution of the right hemisphere to sign comprehension. LHO subjects exhibited greater relative left mid-temporal lobe activation than RHO subjects but less relative left frontal activation (theta band) than RHO subjects during the verbal operator task. It was tentatively concluded that this frontal lobe asymmetry difference was due to a mismatch in strategy preference and coding requirements among RHO subjects.

Treatment of massive posterior epistaxis by detachable coil embolization of a cavernous internal carotid artery aneurysm

We present a case of massive posterior epistaxis caused by a cavernous internal carotid artery aneurysm. This lesion was treated with endovascular placement of electrolytically detachable platinum embolization coils. The treatment resulted in cessation of epistaxis until the patient's death 3 months following embolization. We discuss aspects of using these above coils for this condition.

Endovascular detachable balloon embolization therapy of cavernous carotid artery aneurysms: results in 87 cases

Interventional neurovascular techniques for treating patients with intracranial aneurysms are now being performed in selected cases. In certain anatomical locations that are difficult to reach surgically, such as the cavernous portion of the internal carotid artery (ICA), this technique may be especially useful. The procedure is performed from a transfemoral approach, using local anesthesia, thus permitting continuous neurological monitoring. Between 1981 and 1989, 87 patients diagnosed as having an intracavernous aneurysm were treated with endovascular detachable balloon embolization techniques. The patients ranged in age from 11 to 84 years. The presenting symptom was mass effect in 69 cases (79.3%), rupture of a preexisting aneurysm resulting in a carotid-cavernous sinus fistula in eight cases (9.2%), trauma resulting in a cavernous pseudoaneurysm in seven cases (8.0%), and hemorrhage in three cases (3.4%). Therapeutic occlusion of the ICA across or just proximal to the aneurysm neck was performed in 68 patients (78.2%). Since 1984, with the development of a permanent solidifying agent (2-hydroxyethyl methacrylate) to fill the balloon, it is now feasible in some cases to guide the balloon directly into the aneurysm and preserve the parent artery; this was achieved in 19 cases (22%). Follow-up examination has demonstrated complete thrombosis with partial or total alleviation of symptoms in all patients with therapeutic occlusion of the parent vessel. Of the 19 patients with preservation of the parent artery, follow-up studies have demonstrated total exclusion in 12 cases (63%) and subtotal occlusion of greater than 85% in seven cases (37%), with clinical improvement in all cases. Complications from therapy included transient cerebral ischemia during or after therapy requiring volume expansion in seven cases, embolic symptoms requiring antiplatelet medication in two cases, and stroke in four cases; there were no deaths. Detachable balloon embolization therapy, particularly for large and giant symptomatic aneurysms of the cavernous ICA, can be an effective mode of treatment.

Treatment of intracranial aneurysms with preservation of the parent vessel: results of percutaneous balloon embolization in 84 patients

Treatment of intracranial arterial aneurysms by interventional neurovascular techniques is now being performed in selected cases. From a transfemoral approach, under local anesthesia, a detachable silicone microballoon can be guided through the intracranial circulation, directed into the aneurysm, inflated with a polymerizing agent for solidification, and detached. The goal is to exclude the aneurysm from the circulation and preserve flow through the parent artery. Since 1984, 84 patients have been treated by this technique. The patients ranged in age from 15 to 83 years (mean age, 48) and included 63 females and 21 males. The distribution of aneurysms included 59 in the anterior circulation and 25 in the posterior circulation. The presenting symptom or cause was mass effect in 45 patients (53.6%), subarachnoid hemorrhage in 31 patients (36.9%), carotid-cavernous sinus fistula resulting from rupture of an intracavernous aneurysm in six cases (7.1%), trauma in one case, and transient cerebral ischemia due to emboli in one case. Permanent complications directly related to therapy included 15 deaths and nine cases of stroke. Clinical and radiologic follow-ups were performed 1, 3, and 12 months after treatment; duration of follow-up ranged from 3 to 68 months (mean, 35.5 months). In 65 cases (77.4%) there was evidence of complete aneurysmal occlusion, and in 19 cases 922.6%) there was subtotal occlusion greater than 85%. Interventional techniques for treatment of intracranial aneurysms may be useful as a therapeutic alternative in those patients not amenable to standard surgical therapy.

Continuity and change in preferred provider organizations

This paper presents the results from a national survey of preferred provider organizations (PPOs) that was conducted in 1988. It is based on telephone interviews conducted by the authors with executives in over 170 PPOs in the United States. We compare the survey results with those obtained from similar surveys conducted in 1985 and 1986, allowing us to assess the extent to which PPOs have grown and changed. We found that PPOs have continued to grow at an extremely rapid rate. During the Summer and Fall of 1988, the time in which the survey took place, 37.6 million people were eligible to use PPO benefits, compared to the 16.5 million figure we obtained two years earlier. We did not find, however, that PPOs are moving in the direction of providing more innovative forms of health care cost containment. Most PPOs still rely on discounts from providers and utilization review to achieve savings. There is little trend towards using incentive reimbursement techniques and choosing preferred providers that have shown themselves to be cost-efficient. We conclude that in the coming years PPOs must demonstrate the ability to control rising health care costs. To accomplish this, they will need to put more pressure on providers to use resources more sparingly. Otherwise, they may lose their market share to other forms of managed care.

Transluminal angioplasty for treatment of intracranial arterial vasospasm

Percutaneous transluminal angioplasty for treatment of intracerebral arterial vasospasm is now being performed in selected cases. Thirty-six vascular territories in 13 patients, ranging in age from 15 to 73 years, have been treated with a new silicone microballoon device. This balloon has allowed mechanical dilatation of segmental and diffuse areas of spastic intracerebral blood vessels less than 1 mm in diameter with return to normal luminal diameter. Follow-up angiography has documented improved cerebral perfusion without return of spasm. In 10 patients (77%), vasospasm was due to subarachnoid hemorrhage following rupture of an intracranial aneurysm. In three patients (23%), spasm with resultant neurological decline occurred during detachable balloon embolization therapy for treatment of an aneurysm. In each case, the vessel caliber returned to normal size following balloon dilatation. In nine (69%) of the 13 cases, balloon dilatation resulted in improvement of neurological function within minutes to hours following the procedure. Transluminal angioplasty techniques may offer an alternative form of therapy in the management of symptomatic arterial vasospasm.

A new porcine bioprosthesis: design rationale and early clinical experience

The Medtronic Intact valve is a third-generation porcine bioprosthesis produced using a leaflet fixation process which imposes virtually zero hydrostatic pressure. This fixation method provides optimal preservation of the original leaflet structure and integrity and should result in an improvement in durability compared to conventional preservation techniques. The biomechanical basis for this hypothesis is presented along with early experience with 118 patients (125 valves). There have been no complications related to primary valve failure and the incidence of other valve related events is acceptable.

Vertebral-body collapse in focal and diffuse disease: patterns of pathologic processes

The radiographic patterns of vertebral-body collapse and/or endplate deformity were examined in 99 autopsy specimens of the thoracolumbar spine with benign and malignant disease. Angling of endplates was found to be highly predictive of underlying malignancy, whereas concavity was more suggestive of benign disease, for both individual vertebral bodies and intact spines (P less than .001). Diffuse-concave, diffuse-angled, and focal-angled patterns were more useful (P less than .001) than the focal-concave pattern (P = .07) in distinguishing between benign and malignant disease for superior endplates, whereas all were equally useful (P less than .025) in inferior endplates. Condition of the adjacent disks, location within the spine, and position of the apex of collapse were not predictive. Although these results and subsequent blinded testing suggest that reliable distinction between benign and malignant vertebral collapse is possible, extrapolation to clinical practice may be inappropriate because of population bias in the study and differences in radiographic quality between autopsy specimens and live subjects.

Aversion/attraction of blue jays to microwave irradiation

Aversion/attraction experiments were conducted to determine whether birds can perceive the presence of 2.45 GHz continuous wave microwave irradiation by observing whether Blue Jays (Cyanocitta cristata) exhibit an attraction or an aversion to the field when exposed to 25 and 50 mW/cm2. At power densities of 25 and 50 mW/cm2 Blue Jays exhibit an aversion to microwave irradiation.

The effects of microwave radiation on avian dominance behavior

Seventeen birds from 12 flocks were exposed to microwave radiation under various combinations of power density and duration; three birds from two additional flocks served as sham-exposed controls. Experiments were conducted outdoors at Manomet, Massachusetts (41 degrees 56'N, 70 degrees 35'W) under normal winter ambient temperatures. Although irradiated birds maintained their positions within a flock hierarchy with one exception, some appeared to have a change in their level of aggression after exposure.

Loss of dendritic spines in aging cerebral cortex

Previous work has shown that the dendritic spines of pyramidal neurons of the cerebral cortex are sensitive to a wide variety of environmental and surgical manipulations. The present study shows that the normal aging process also affects these spines. The spines were studied with the light microscope in Golgi preparations from rats ranging in age from 3 to 29.5 months. Visible spines were counted on either 25 or 53 mu segments of the basal dendrites, apical dendrites, oblique branches, and terminal tufts of layer V pyramidal cells in area 17. A progressive loss of spines occurred at each of these loci. The smallest observed spine loss (24%) occurred on the dendrites of the terminal tuft, and the largest (40%) on the oblique branches. Age-related spine loss appears to affect all animals, and for animals of any one age the overall loss is similar. However, the cell-to-cell variability within an individual animal is pronounced, some cells with high spine densities being present at every age examined. As a general rule, there is a positive relationship between visible spine density along the apical dendrite as it traverses layer IV and the thickness of the dendrite. With advancing age, the relatively thick dendrites decrease in number so that the thinner dendrites make up an increasingly larger proportion of the total apical dendrite population. Questions that remain for the future include the genesis of the spine loss, its relation to other aging changes, and its functional significance for the neuron.