ProQR Therapeutics Announces $8.1 Million in New Funding From Rett Syndrome Research Trust to Expand RNA Editing Collaboration

ProQR Therapeutics NV recently announced an expansion of its collaboration with the Rett Syndrome Research Trust (RSRT). Building on the initial $1 million research grant announced in January 2024, the expanded partnership includes an additional $8.1 million in funding from the RSRT, for a total of $9.1 million. The funding will support the advancement of AX-2402 into clinical trials.

Rett Syndrome, a rare and devastating neurodevelopmental disorder, affects approximately 350,000 people worldwide, predominantly girls. With no current cures and limited treatment options, Rett Syndrome presents a significant unmet medical need. AX-2402 is being developed for individuals with Rett syndrome who have the R270X mutation in MECP2 gene, and is based on ProQR’s proprietary Axiomer RNA editing platform. Axiomer can target many mutations beyond R270X that collectively impact a large segment of the Rett population. Success with AX-2402 sets the foundation for developing RNA editing therapeutics to target the remaining mutations.

“We are deeply committed to bring innovative solutions to patients with high unmet needs, such as those living with Rett Syndrome, and are grateful for the expanded partnership with the Rett Syndrome Research Trust,” said Gerard Platenburg, Chief Scientific Officer of ProQR. “The increased support from RSRT underscores the potential of our Axiomer RNA editing technology platform to address complex genetic CNS conditions. The expanded collaboration enables us to accelerate the development of AX-2402 for Rett syndrome and to advance this program into clinical trials.”

Monica Coenraads, Founder and CEO of the Rett Syndrome Research Trust, added “Individuals with Rett Syndrome live with the profound effects of this condition every day, and they deserve transformative therapies. This partnership with ProQR is exciting and ambitious. We are encouraged by the progress we’ve seen so far and believe that together we are taking critical steps toward achieving our mission of eradicating Rett Syndrome.”

The additional $8.1 million in funding will enable ProQR to accelerate work on RNA editing approaches tailored to the genetic mutations that cause Rett Syndrome. This next phase of the collaboration will focus on optimizing therapeutic candidates targeting the transcription factor Methyl CpG binding protein 2 (MECP2) and advancing them toward clinical development.

ProQR is pioneering a next-generation RNA base editing technology called Axiomer, which could potentially yield a new class of medicines for diverse types of diseases. Axiomer “Editing Oligonucleotides”, or EONs, mediate single nucleotide changes to RNA in a highly specific and targeted way using molecular machinery that is present in human cells called ADAR (Adenosine Deaminase Acting on RNA). Axiomer EONs are designed to recruit and direct endogenously expressed ADARs to change an Adenosine (A) to an Inosine (I) in the RNA – an Inosine is translated as a Guanosine (G) – correcting an RNA with a disease-causing mutation back to a normal (wild type) RNA, modulating protein expression, or altering a protein so that it will have a new function that helps prevent or treat disease.

Rett syndrome is a progressive neurodevelopmental disorder caused by genetic mutations in the Methyl CpG binding protein 2 (MECP2) and diagnosed primarily in females. It is characterized by apparently normal psychomotor development during the first six to 18 months after birth, followed by a period of developmental stagnation, then a regression in language and motor skills, followed by long-term relative stability. During the phase of regression, affected patients develop repetitive, stereotypic hand movements that replace purposeful hand use. Additional symptoms include gait ataxia and apraxia, seizures, tremors, episodic apnea and/or hyperpnea, gastrointestinal issues, scoliosis and musculoskeletal problems, anxiety and sleep issues and bruxism.

ProQR Therapeutics is dedicated to changing lives through the creation of transformative RNA therapies. ProQR is pioneering a next-generation RNA technology called Axiomer, which uses a cell’s own editing machinery called ADAR to make specific single nucleotide edits in RNA to reverse a mutation or modulate protein expression and could potentially yield a new class of medicines for both rare and prevalent diseases with unmet need. Based on our unique proprietary RNA repair platform technologies we are growing our pipeline with patients and loved ones in mind. For more information, visit www.proqr.com.