Tag Archive for: RNA therapy

Are rabbit eyes and cell models suitable?

LEES ARTIKEL IN NEDERLANDS

Assessment of safety and toxicity of genetic patches

Inherited retinal diseases, such as Usher syndrome (deafblindness), are rare conditions that result in a gradual loss of vision. These diseases have a significant impact on the quality of life of patients and their families. While most inherited retinal diseases remain largely untreatable, significant progress has been made in recent years. RNA therapies are being developed that use “genetic patches.” A major focus in the development of such therapies is the high cost associated with safety and toxicity testing of genetic patches.

One requirement that must currently be met before genetic patches can be tested in patients is that their safety—meaning that they are not toxic, harmful, or dangerous—must be demonstrated in two different vertebrate species, one of which must be a primate.

Genetic patch for each mutation
The genetic patch is specifically developed for a particular mutation or group of mutations within a gene. It has already been demonstrated in animal models and in clinical trials that genetic patches developed to mask exon 13 in the USH2A gene are safe. However, these results do not guarantee that the same will hold true for genetic patches designed for other mutations and exons. Consequently, the same tests to confirm the safety of these newly developed genetic patches must be performed. These tests are costly, time-consuming, and involve the use of many animals.

RETOX project
The “RETOX” project (Rabbit Eyes for AON-induced TOXicity evaluation), a collaboration between Radboudumc, Astherna BV, and Stichting Ushersyndroom, aims to investigate whether rabbits can be used as the sole species to rule out potential toxic reactions to genetic patches. Additionally, the project will explore whether these toxicity and safety tests can be conducted in cultured cells in the future.

If the results of the RETOX project demonstrate that rabbits are indeed suitable for determining the toxicity of genetic patches, it would significantly reduce the development costs of these therapies and decrease the number of animals used during the development of genetic patch therapies.

Read more about this study on the Health Holland website:
Suitability of rabbits and in vitro models for toxicity assessments | Health~Holland

Resumption of the clinical trial for RNA therapy for USH2a has been terminated

UPDATE September 27, 2023

In mid-August, we reported that ProQR Therapeutics, which had previously been forced to halt its two promising clinical trials, had found a new partner in Laboratoires Théa (Théa) to continue development. Unfortunately, this collaboration has been terminated prematurely.

One of the conditions for finalizing the agreement was that several key ophthalmic employees of ProQR would enter into employment with Théa. Regrettably, some employees have decided not to proceed with this, making it impossible to meet this closing condition. As a result, Théa has terminated the agreement.

The immediate consequence is that the clinical trial testing RNA therapy for individuals with Usher syndrome 2A will not be resumed at this time.

The full press release can be read here.

 

LEES ARTIKEL IN NEDERLANDS

ProQR has announced an agreement with Laboratoires Théa to acquire Ultevursen  programs.

In August 2022 ProQR decided to focus exclusively on the development of the Axiomer® RNA editing technology platform. ProQR Therapeutics was forced to stop promising clinical trials unless they found a new strategic partner to continue.
Read about this: https://www.ushersyndroom.nl/klinische-trials-celeste-en-serius-worden-noodgedwongen-stopgezet/

The new partner
Laboratoires Théa (Théa) has signed an agreement with ProQR to continue the further development of the IRD Sepofurses and Ulteverses programs. Théa is European pharmaceutical company specialized in the research, development, and commercialization of eye care products. This family-owned is based in Clermont-Ferrand, France.

Within Théa, a fully dedicated team specializing in inherited retinal disorders and a new organization are currently being set up to manage these projects. More information on the next steps for these programs will be available in the coming weeks from Théa.

About Ultevursen
Ultevursen (formerly QR-421a) is a first-in-class investigational RNA therapy designed to address the underlying cause of vision loss in Usher syndrome type 2a and non-syndromic retinitis pigmentosa due to mutations in exon 13 of the USH2A gene. QR-421a is designed to restore functional usherin protein by using an exon skipping approach with the aim to stop or reverse vision loss in patients. Ultevursen is intended to be administered through intravitreal injections in the eye and has been granted orphan drug designation in the US and the European Union and received fast-track and rare pediatric disease designations from the FDA.

The transaction is expected to close in the third quarter of 2023.

For further information or enquiries about the announcement today, please email: patientinfo@proqr.com.

The press release from ProQR can be found via this link.

Read more about RNA therapy on our Knowledge Portal:
https://www.ushersyndroom.nl/en/knowledge-portal/research/rna-therapy/

Positive results of QR-421a Phase 1/2 Clinical Trial for Usher Syndrome and non-syndromic Retinitis Pigmentosa

 

ProQR has published positive results from its Phase 1/2 Stellar trial of QR-421a, an investigational RNA therapy for the treatment of Usher syndrome and retinitis pigmentosa (RP) due to mutation(s) in exon 13 of the USH2A gene.

Stellar study
The Stellar study is a first-in-human clinical trial of the medicine QR-421a. The Phase 1/2 study includes adults that experience different levels of vision loss due to mutation(s) in exon 13 of the USH2A gene. This trial aims to study the safetly profile and efficacy of QR-421a.

QR-421a is an investigational RNA therapy designed to skip exon 13 in the RNA with the aim to stop vision loss.

A total of 20 clinical trial participants took part in the Stellar study. The trial design consisted of four study groups of which three groups received QR-421a at three different dose levels. A fourth group received sham treatment, where an intravitreal injection is mimicked but no injection or study drug is given. For each participant one eye was treated with a single injection of QR-421a or sham, and the fellow untreated eye was a control.

Summary

  • QR-421a was observed to be well tolerated with no serious adverse events reported.
  • QR-421a also demonstrated benefit in multiple measures of vision, including best corrected visual activity (BCVA), static perimetry, and retinal imaging (OCT).

Next steps
Based on the safety profile and early evidence of efficacy observed to date, ProQR plans to conduct two final stage/pivotal Phase 2/3 clinical trials.

The two-final stage/pivotal Phase 2/3 clinical trials, named: Sirius and Celeste, will study two different patient populations.
The Sirius study is a Phase 2/3 trial that will focus on advanced clinical trial participants with BCVA of equal or worse than 20/40. The preliminary design for Sirius is a doublemasked, randomized, controlled, 24-month, multiple-dose study.
In parallel to Sirius, the Celeste study is a Phase 2/3 trial focusing on early-moderate clinical trial participants with BCVA of better than 20/40. The preliminary design for Celeste is a double-masked, randomized, controlled, 24-month, multiple-dose study.

Read more about the results of the Stellar study here.

This study is based on the research and findings of Dr. Erwin van Wijk at the Radboudumc

Read also: Leiden ProQR is further expanding Radboudumc research