Drug development is a long, expensive, and difficult process. Not every treatment being created makes it to the end of the clinical trial process, much less through FDA approval. Takeda Pharmaceuticals experienced this firsthand when they halted all development of their investigational Hunter syndrome therapy, TAK-609. Want to read more? You can find the source article from Global Genes.
About Hunter Syndrome
First, let’s talk about what this rare disease is. Hunter syndrome, also known as mucopolysaccharidosis II (MPS II), is an extremely rare, genetic disorder caused by a lack of the enzyme iduronate 2-sulfatase. This enzyme is responsible for breaking down complex molecules, and without it these molecules build up and damage the body. This damage gets progressively worse as time passes, and it eventually causes permanent damage that affects appearance, mental development, organ function, and physical abilities. This disorder is inherited through a chromosome from the mother and is far more common in males than females.
Due to the buildup of harmful molecules, symptoms do not begin to present until age two to four. They can be mild to severe depending on the person who has it. Symptoms include an enlarged head, thicker lips, a broad nose with flared nostrils, a protruding tongue, a deep or hoarse voice, abnormalities in the skeletal system, a distended abdomen due to enlarged internal organs, chronic diarrhea, white skin growths, joint stiffness, aggressive behavior, stunted growth, and delayed development. Along with these symptoms, Hunter syndrome can bring other complications depending on its severity. Respiratory, cardiac, brain, nervous system, skeletal, and connective tissue complications are all possible when one has this syndrome. There are currently no cures for this disorder, although numerous therapies are currently being investigated, and treatment is symptomatic.
Halted Development for TAK-609
Takeda announced that they would no longer be developing TAK-609 for Hunter syndrome patients in their quarterly earnings report. This comes after many, many sessions and words with the FDA – years worth, in fact.
Looking back towards the history of TAK-609, Takeda took ownership of the therapy after acquiring Shire in 2019. This was already after Shire reported a failed phase 2/3 clinical trial, in which TAK-609 did not meet any endpoints. The study’s primary endpoint was change from baseline in General Conceptual Ability (GCA) scores, which measure cognitive ability. Looking to the secondary endpoint, it focused more on behavior, as it was change in baseline in Adaptive Behavior Composite (ABC) scores.
While this discontinued development is very disappointing, especially after years of hard work, Takeda remains firm in their commitment to bring treatments to patients with Hunter syndrome and other similar disorders.
About TAK-609
Injected into the spinal canal, TAK-609 is an investigational form of idursulfase. While still in development, it was to be indicated for pediatric patients living with Hunter syndrome paired with cognitive impairment.
Looking Forward
Even though this research ended in failure, that does not mean that it did not provide useful information and insights. Failed research can pave the way to successful treatments as medical professionals learn from mistakes and what did not work. Hopefully, the effort put into TAK-609 will spur more research and future treatments for this rare disease.
