Japan's Ministry of Health, Labor and Welfare (MHLW) has granted orphan regenerative medicine product designation to Kyowa Kirin and Orchard Therapeutics’ ex vivo autologous hematopoietic stem cell (HSC) gene therapy, OTL-200, for metachromatic leukodystrophy (MLD).
The therapy is intended to treat pre-symptomatic early juvenile (PSEJ) MLD, pre-symptomatic late infantile (PSLI) MLD and early-symptomatic early juvenile (ESEJ) MLD, together known as early-onset MLD, a life-threatening neurometabolic condition.
MLD occurs due to a genetic error that disrupts production of the arylsulfatase A enzyme (ARSA), leading to severe neurological damage.
Also referred to as atidarsagene autotemcel, OTL-200 addresses the fundamental genetic issue in MLD by incorporating functional copies of the ARSA gene into the patient's HSCs outside the body, utilising a lentiviral vector.
The cells, which are genetically modified, are then reintroduced into the patient.
Upon engraftment, these cells differentiate into various types of cells, with some crossing the blood-brain barrier to enter the central nervous system, where they produce the functional enzyme.
Kyowa Kirin's preparations are underway to begin a clinical study in Japan for the therapy targeting children with PSEJ, PSLI and ESEJ MLD.
The therapy has also secured orphan drug status and priority review from the Saudi Food and Drug Authority for early-onset MLD treatment.
Efforts are also being made by Orchard Therapeutics to qualify a treatment centre in the Kingdom of Saudi Arabia to administer OTL-200 to children with MLD via pre-approval access programmes and, subject to approval, for commercial distribution.
OTL-200 has secured approval in the US and Europe under the trade names Lenmeldy and Libmeldy respectively.
Kyowa Kirin chief medical officer and executive vice-president Takeyoshi Yamashita stated: “We are very pleased that OTL-200 has received designation as an orphan regenerative medicine product in Japan.
“This designation underscores the importance of OTL-200 as an innovative treatment for young patients suffering from MLD, a life-threatening and severe neurodegenerative disease for which no treatment has existed until now.”
In 2024, Kyowa Kirin completed its acquisition of Orchard Therapeutics for an equity value of $477.6m (Y70.47bn).
