un recentissimo aggiornamento sulla sperimentazione del tanto discusso vitrase:
Vitrase trials show reduction in vitreous hemorrhage density
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IRVINE, Calif. — Intravitreous injection of a hyaluronidase product demonstrated a significant reduction in vitreous hemorrhage density in data pooled from two phase 3 trials, according to recent publications.
Ista Pharmaceuticals announced this week that the results of two phase 3 trials evaluating its product Vitrase (ovine hyaluronidase) for the treatment of vitreous hemorrhage have been published in the American Journal of Ophthalmology.
Vitrase was approved by the Food and Drug Administration as a spreading agent for ocular anesthesia in 2004. It was reviewed by an FDA advisory panel in 2003 for the indication of vitreous hemorrhage clearing but was not recommended for approval of that indication.
According to Ista, in the pooled data from the two phase 3 trials, the drug demonstrated a statistically significant reduction in vitreous hemorrhage at 1 month after a single intravitreous injection, compared to a single injection of saline.
The reduction in hemorrhage density allowed investigators to see into the posterior segment to diagnose the underlying cause of the hemorrhage and to treat with laser when appropriate, according to a press release from the company.
Two randomized, double-masked, placebo-controlled international studies were conducted, enrolling a total of 1,306 patients. A North American study involved 750 patients who received either saline injection or 7.5 IU, 55 IU or 75 IU of Vitrase. A study outside North America included 556 patients who received either saline injection or 55 IU or 75 IU of Vitrase, according to the press release.
Patients in the study all had severe vitreous hemorrhage with a visual acuity worse than 20/200 at the time of enrollment.
“The study results suggest a therapeutic utility of ovine hyaluronidase in the management of vitreous hemorrhage,” said Lisa R. Grillone, PhD, vice president of clinical research and medical affairs at Ista, in the release. “This may allow for earlier treatment of the underlying pathology while minimizing the risk to the patient.”
Dr. Grillone was one of the authors of two papers published in AJO describing the safety and efficacy results from the pooled study data.
“The goal of treatment with an intravitreous injection of ovine hyaluronidase is to provide a safe treatment alternative to reduce and/or clear vitreous hemorrhage density sufficiently to provide earlier visualization of the retina,” Dr. Grillone said. “This would facilitate the physician’s ability to diagnose the underlying retinal pathology and assess the need for additional treatment, as well as restore the subject’s visual acuity when there is adequate retinal function.”
The two phase 3 trials demonstrated that patients receiving a single Vitrase injection showed improved best corrected visual acuity by three or more lines from 1 month through 3 months after injection, compared to those who received saline injection, according to the release.
“No serious safety issues” were observed following a single injection of Vitrase in the trials, according to the press release. The most common adverse effect during the trials was acute iritis, the release said.
“Other statistically significant ocular adverse events observed in the two trials, one of which was conducted outside North America, were hyperemia and ocular pain,” the release stated. “Additional statistically significant ocular adverse events in the North American study included eye irritation, increased lacrimation, reduced visual acuity, vitreous hemorrhage, photophobia and photopsia.”
una breve disamina sulla diffusione percentuale delle emorragie vitreali nell'isola di singapore e la possibilità di trattarle nel giro di pochissimi anni con iniezioni di vitrase: (il tono dell'articolo è molto ottimistico)
Direi di sì Cece, anche se i pazienti che si intende trattare per primi con questa tecnica non sono quelli con una semplice degenerazione precoce del vitreo, ma quelli con emorragie endoculari. Però sembra che, in dosi opportunamente calibrate, questo tipo di farmaci possano aiutare a sciogliere gli addensamenti senza causare un ulteriore distacco posteriore del vitreo. E' chiaro che dalla teoria e dallo studio su cavie alla pratica clinica passano molti anni, però fa ben sperare il fatto che staino pensando di usare già il farmaco, anche se per opacità ben più serie delle nostre.
non essendoci al momento sperimentazioni mediche per una cura delle miodesopsie, è comunque importante che progrediscano studi sull'impiego di enzimi per curare patologie vitreoretinali.
anche se il vitrase non è stato pensato specificamente per le miodesopsie, una volta stabilita la sua innocuità per il corpo vitreo, potrebbe essere utilizzato in futuro per il nostro problema, una volta trovato il giusto dosaggio. per ora resta solo un'ipotesi.
Trovato in giro per la rete.
In effetti potrebbe essere una soluzione futura. Personalmente spero sempre in una soluzione farmacologica perchè un'operazione non è mai gradita, ma se fosse la soluzione definitiva sarebbe sempre meglio che tenersi le mosche.
i risultati della terza fase di sperimentazione del vitrase:
1: Am J Ophthalmol. 2005 Oct;140(4):585-97. Related Articles, Links
Safety results of two phase III trials of an intravitreous injection of highly purified ovine hyaluronidase (Vitrase) for the management of vitreous hemorrhage.
Kuppermann BD, Thomas EL, de Smet MD, Grillone LR; Vitrase for Vitreous Hemorrhage Study Groups.
Department of Ophthalmology, University of California, Irvine, Irvine 92697, California. bdkupper@uci.edu
PURPOSE: To evaluate the safety of intravitreous ovine hyaluronidase for the management of vitreous hemorrhage. DESIGN: Two prospective, randomized, placebo-controlled, double-masked studies. Pooled efficacy data are presented in a companion article in this issue of The Journal. METHODS: Subjects with vitreous hemorrhage > or = 1 month, severe at entry and best corrected visual acuity (BCVA) worse than 20/200 in the study eye were randomized to 7.5 IU, 55 IU, 75 IU ovine hyaluronidase, saline, or no injection. Assessments occurred on day 1, week 1, months 1, 2, 3, 6, and then every 6 months for as long as 32 months. Assessments included history, ocular symptoms, adverse events, BCVA, intraocular pressure, external eye examination, slit-lamp biomicroscopy, fundus examination, B-scan ultrasonography, and fundus photography. RESULTS: Of 1362 subjects in the safety population, 1344 received hyaluronidase or saline and 18 no treatment. Iritis was the most common ocular adverse event, occurring in 33.3%, 62.1%, 58.9%, and 62.1% of saline, 7.5 IU, 55 IU, and 75 IU-treated subjects. In eyes with more than mild iritis, a dose response was observed: 8.9%, 20.2%, 33.7%, and 39.7% of saline, 7.5 IU, 55 IU, and 75 IU-treated subjects, respectively, were noted to have moderate or severe iritis. Retinal detachments (RDs) were reported in 9.5% of study eyes: 26 (6.9%), 22 (11.1%), 35 (9.3%), and 45 (11.5%) in the saline, 7.5 IU, 55 IU, and 75 IU-treated subjects. Overall, 1.8% of study eyes had rhegmatogenous RD: 1.1%, 2.5%, 1.6%, and 2.3% of saline, 7.5, 55, and 75 IU treated subjects. Cataracts occurred similarly across treatment groups. No injection-related infectious endophthalmitis was reported. CONCLUSIONS: No serious safety issues were reported after a single intravitreous injection of ovine hyaluronidase. RD incidence was not statistically different between groups. Iritis manifesting as an acute self limited inflammation was the most common adverse event, occurred in a dose response fashion, but was not noted to result in a serious adverse event in any hyaluronidase treated eye.
Publication Types:
Clinical Trial
Clinical Trial, Phase III
Multicenter Study
Randomized Controlled Trial
Dr. Kuppermann discussed studies on these 2 drugs as agents for pharmacologic vitreolysis. Vitrase (purified ovine lyophilized hyaluronidase, ISTA Pharmaceuticals) completed 2 large phase 3 studies assessing its safety and efficacy for clearance of vitreous hemorrhage, but the 2 pivotal studies did not result in the drug being approved for that indication. "While Vitrase showed a clinical benefit in clearing vitreous hemorrhage in some eyes, the data did not show statistical significance in its 2 individual trials for a variety of complex reasons," explained Dr. Kuppermann.
Vitrase is currently approved as a spreading agent for retrobulbar use, and is available as an off-label agent for intravitreal use. Dr. Kuppermann also discussed the use of Vitrase to induce a posterior vitreous detachment in patients with moderately severe non-proliferative diabetic retinopathy (PDR) in order to decrease the risk of progression to proliferative diabetic retinopathy. However, to date, only a pilot trial for this indication has been conducted with Vitrase.
Dr. Kuppermann also discussed the potential role of another agent for enzymatic vitreolysis, plasmin. He reported that 3 types of plasmin were in various stages of development — autologous plasmin, pooled plasmin, and microplasmin. Autologous plasmin is difficult to develop as a commercial product because it entails using an affinity cartridge to extract the plasmin from the patients' blood. Dr. Kuppermann saw either pooled plasmin (Bausch & Lomb) or microplasmin (ThromboGenics) as the more likely plasmin-based future of therapeutic agents. Dr. Kuppermann explained that pooled plasmin and microplasmin are being studied as surgical adjuvants for vitrectomy surgery in ongoing trials, and other indications are being explored as well.
He also pointed out some other possible indications for both drugs. "Future potential uses include the possibility of using vitreolytic agents such as Vitrase and plasmin for floaters, as well as modifying or enhancing the efficacy of other ophthalmic drugs," said Dr. Kuppermann.
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