There are no cures for MPS and ML, and there are only a handful of approved treatments. However, there are a number of emerging treatments and therapies currently in development at the following companies:
Abeona is developing next generation adeno-associated viral (AAV)-based gene therapies for MPS III (Sanfilippo syndrome), which involves a one-time delivery of a normal copy of the defective gene to cells of the central nervous system with the aim of reversing the effects of the genetic errors that cause the disease.
AGT‑181 is a novel, investigational enzyme replacement therapy (ERT) for the treatment of neurological complications in patients with Hurler syndrome. The ERT has received Fast Track designation from the FDA. AGT-182 is a fusion protein of iduronate-2-sulfatase (IDS), engineered to cross the blood brain barrier in MPS II patients. AGT‑184 and AGT-187 are investigational enzyme replacement therapies (ERT) for the treatment of Sanfilippo A and B syndromes and have shown enzyme activity comparable to recombinant SGSH in animal studies.
ELX-02 is a translation read-through inducing drug (TRID). Read-through therapy is a treatment strategy for genetic diseases caused by nonsense mutations to increase translation and restoring activity of the mutated proteins.
ESTEVE and the Universitat Autònoma de Barcelona (UAB) create a promising platform of gene therapy projects with the addition of two new therapies for Sanfilippo B (EGT-201) and Hunter syndromes (EGT-301).
ISP™ therapy strikes a balance between the benefits of a HSCT, and risk profile of ERT. Despite the risks, HSCT has the ability to halt progression of the neurological deficit and prevent premature death due to heart or liver disease. An ISP™-based treatment for MPS I is less risky because it uses the patient’s own cells, doesn’t require myeloablative chemotherapy,and can be turned off once administered. Immusoft is currently filing regulatory documentation to support a Phase Ia/Ib clinical trial to treat MPS I with an ISP™ cell therapy product.
IVA336 has demonstrated good tolerability, safety and efficacy in phase I and phase IIa studies, in approximately 700 healthy volunteers and 1100 patients. The drug has been investigated in several preclinical models and its potential has been proven in MPS. It may be therefore anticipated that IVA336 could prove beneficial to MPS patients (MPS I, II and VI) as a substrate reduction therapy as a stand-alone treatment on in adjunction to current treatments.
Lysogene is developing a gene therapy candidate for the treatment of MPS IIIA, which is designed to use the AAVrh10 vector to deliver the human SGSH gene directly to the central nervous system. The company expects to begin enrollment in a Pivotal Phase clinical trial in the first half of 2018. The company recently completed the enrollment for the first multi-national observational study in MPS IIIA which will function as the non-concurrent control for the first pivotal trial for MPS IIIA in H1 2018. Lysogene has obtained orphan drug designation from the EMA and FDA and rare pediatric designation by the FDA.
The MeuSIX consortium plans to conduct a multicenter phase 1/2 clinical trial to investigate the safety and efficacy of AAV-mediated gene therapy in patients with MPS VI. An orphan drug designation (ODD) has been obtained from both the European Medicinal Agency and the US Food and Drug Administration for the MPS VI therapeutic AAV vector.
Dr. Haiyan Fu’s team in the Center for Gene Therapy has developed a systemic gene delivery approach to restore the activity of the enzyme (α-N-acetylglucosaminidase) in the central nervous system and somatic system, showing functional benefits in treating MPS IIIB I mouse model.
The U.K.-based company is currently working on a lentivirus-based autologous ex-vivo gene therapy for Sanfilippo syndrome type B (or MPS-IIIB). Data and information are still being collected before moving to the human clinical trial phase.
RGX-111 is a product candidate for the treatment of Mucopolysaccharidosis Type I (MPS I), which is designed to use the AAV9 vector to deliver the human α-l-iduronidase (IDUA) gene to the central nervous system (CNS). The company plans to file IND for RGX-111 for the treatment of MPS I in mid-2017 and expect to begin enrollment in a Phase I/II clinical trial in the second half of 2017. RGX-111 has received orphan drug product and rare pediatric disease designation from the FDA.
SB-318 (MPS I) and SB-913 (MPS II) are designed to provide stable, continuous production of the enzymes IDUA (MPS I) or IDS (MPS II) for the lifetime of the patient. Sangamo’s approach is designed to enable the liver to permanently produce circulating therapeutic levels of a corrective enzyme product. As of Nov. 15, 2017, Sangamo treated its first gene editing patient in clinical trial setting.
Planning a study to obtain blood samples from patients who completed Shire study HGT-ELA-038 and to confirm the suitability of such blood samples for validation of the CRIM assay. If the samples are suitable, the CRIM status will be correlated with various clinical parameters data collected in HGT-ELA-038.
Sobi is in the late stages of preclinical development of SOBI003. Preclinical studies to date with repeated systemic infusions have demonstrated efficacy in reducing substrate levels in the brain and signs of disease modifying effects. Sobi is preparing for clinical studies, which it plans to start in 2018. Clinical studies will focus on exploring the safety and efficacy of SOBI003 in MPS IIIA patients.