At the recent 20th Huntington’s Disease Therapeutics
Conference in February, four pharmaceutical companies provided updates on their
key clinical trial programs, demonstrating that they had overcome basic safety
hurdles and revealing plans to have their drugs potentially approved as
therapies (treatments) for delaying the progression of HD symptoms.
All four programs use drugs to lower the amount of harmful
mutant huntingtin protein in the brain cells of patients.
In the first of two
articles on these programs, I described the projects of PTC Therapeutics and
Roche.
In this article, I cover the presentations made by Wave Life Sciences and uniQure.
These updates took place during the conference’s first
session on February 25, the first day of the three-day event.
In a post-conference interview
Robert Pacifici, Ph.D., the chief scientific officer for CHDI Foundation, Inc.,
the conference sponsor, told me that that there is “great promise” regarding
these four programs’ potential HD therapies.
Attacking
only the bad protein, preserving the good one
Jane Atkins, Ph.D., Wave’s senior vice president for
portfolio strategy and program management, provided an update on the company’s
groundbreaking program.
Like Roche’s tominersen, Wave’s WVE-003 is an antisense
oligonucleotide, an artificial strand of DNA that blocks or lowers the
production of the huntingtin protein.
However, whereas tominersen and PTC’s votoplam (a splicing
modulator) reduce both the mutant and
normal huntingtin protein, Wave’s drug is uniquely allele-selective: it attacks
just the bad protein and allows the good one to carry out its essential actions
unhampered.
Clinical trials for drugs usually go through three phases.
If the last is successful, the drug can receive approval from the U.S. Food and
Drug Administration (FDA).
In 2021, in small clinical trials, precursors WVE-120101 and
WVE-120102 failed to reduce the bad protein.
Wave then developed WVE-003, which entered a clinical trial that same year.
At the conference, Dr. Atkins reported that in June 2024 the Phase 1b/2a SELECT-HD study of WVE-003 produced positive results,
“including the first allele-selective silencing in any disease.”
“A growing body of literature” supports the importance of
the good huntingtin protein, she explained, as it sustains the health of brain
cells.
Slowing
the shrinking of the brain
In the clinical trial, the bad protein was reduced as much
as 46 percent in some volunteers, exceeding the overall goal of 30 percent, Dr.
Atkins said, noting that the drug was safe and well-tolerated.
Significantly, the study also demonstrated a slowing in the
atrophy (shrinking) of the caudate, a key part of the brain dramatically affected in HD,
leading to a decline in cognition, function, and movement, Dr. Atkins said.
Such atrophy occurs before symptoms
appear, she noted, so being able to observe this change early makes the atrophy
a good measure of a drug’s effectiveness.
The slower shrinking “was the first time this was shown in
the clinic,” Dr. Atkins said. “We were super-excited to see this.”
With these promising results, Wave plans to put WVE-003 into
a combined Phase 2/3 clinical trial, Dr. Atkins said. The company later this
year expects to seek FDA approval of the trial. Wave proposes to use caudate
atrophy as a primary endpoint, that is, a main measure of WVE-003’s
effectiveness.
Wave is also investigating WVE-003’s potential impact on
somatic expansion, Dr. Atkins said. Somatic expansion is the tendency of the
mutant huntingtin gene to continue expanding over time. Many scientists now
believe that this process triggers HD symptoms.
Somatic expansion is understood as a two-step process where expansion of the gene (step 1) triggers disease (step 2) that drives HD. Wave believes that lowering the bad protein selectively (with WVE-003) is likely to address the second step.
As with tominersen, WVE-003 is administered via a spinal
tap. Votoplam is a pill.
Dr. Jane
Atkins of Wave Life Sciences displays a slide demonstrating the slowing of
caudate atrophy in the WVE-003 clinical trial (photo by Gene Veritas, aka
Kenneth P. Serbin).
uniQure
drug slows disease progression in trial
David Margolin, M.D., Ph.D., uniQure’s vice president for
clinical development, gave a presentation on the latest developments regarding
AMT-130, the firm’s gene therapy drug that reduces the levels of both the good
and bad huntingtin protein.
In the uniQure clinical trial, a neurosurgeon injects AMT-130
directly into the brains of the volunteers under the guidance
of an MRI. As a gene therapy, AMT-130 requires just this one application.
(Watch the uniQure video about how AMT-130 is administered here).
This small, long-term uniQure Phase 1/2 trial began in 2020.
As of April, the number of participants had reached 45, including people from
the U.S. and Europe.
An interim analysis in mid-2024 showed that “AMT-130 high dose …
strongly and significantly reduced disease progression,” Dr. Margolin pointed
out. Another analysis found “substantial reduction in risk of clinically
meaningful worsening,” he added.
As patients continue to go through the trial and beyond,
with follow-up, “with every data cut we see… a promising treatment effect
becoming more and more evident,” Dr. Margolin said.
Dr. David
Margolin of uniQure presents data illustrating the slowing of HD disease
progression in the AMT-130 clinical trial (photo by Gene Veritas).
Hoping
to accelerate approval
The positive results have led uniQure to seek acceleration
of FDA approval for AMT-130.
Because of HD’s status as a rare disease, in 2017 uniQure
received the financially beneficial orphan drug designation
from the FDA for AMT-130. In 2019, FDA granted AMT-130 fast track status to
further facilitate development of the drug and expedite review.
As explained by Dr. Margolin at the conference, in 2024 the
FDA defined AMT-130 as a regenerative medicine advanced therapy (RMAT).
This category includes life-threatening diseases such as HD.
Dr. Margolin said it is applicable to new kinds of drugs such as gene therapy,
cell therapy, and tissue-engineered products, and it further accelerates FDA
review.
In achieving this designation, uniQure presented to the FDA
the data from the Phase 1/2 trial, and the FDA agreed that this data can serve
as the primary basis for a drug application, Dr. Margolin said.
Dr. Margolin indicated that this determination means that
uniQure will not need to put AMT-130 into a Phase 3 trial.
“An additional investigational study will not be required,” he emphasized. “That
accelerates by several years the timeframe in which AMT-130 might become
available to a wider U.S. cohort of patients.”
Swaying
the FDA to be more flexible
Because of the lack of therapies that modify the course of
this rare and devastating disease, the uniQure project and the company’s
dialogue with the FDA have indicated the willingness of the agency to allow
flexibility in clinical trial programs and a faster timeline.
Dr. Margolin’s talk title included the phrase “alignment on
a US Regulatory Path Via RMAT.” Alignment with the FDA could lead to an
“accelerated approval” for AMT-130, he observed.
Dr. Margolin asserted that uniQure’s dialogue with the FDA
“has meaningfully advanced HD regulatory science.”
In response to a question from Dr. Pacifici about the
negotiations with the FDA, Dr. Margolin stated that uniQure hopes that the lack
of disease-modifying therapy is “swaying FDA to be more liberal than they have
been in the past.”
Dr. Pacifici asked what additional studies uniQure will
conduct if it secures the accelerated approval, which would still be only
conditional.
Dr. Margolin replied that uniQure will discuss that matter
with the FDA.“Importantly, even an accelerated approval means the drug will be
available to patients,” Dr. Margolin stressed. “It does constrain promotional
materials in certain ways, but would have no relevant impact on its potential
availability and accessibility to U.S. patients.”
A
Breakthrough Therapy designation
AMT-130 gained RMAT designation because it is a gene
therapy. Since the conference, the AMT-130 program has made yet further
progress.
On April 17, uniQure announced that the FDA granted
Breakthrough Therapy designation
to AMT-130.
“Receiving Breakthrough Therapy designation underscores both
the urgent need for effective treatments for Huntington’s disease and the
encouraging interim data demonstrating that AMT-130 has the potential to slow
disease progression,” said Walid Abi-Saab, M.D., chief medical officer of
uniQure, in a press release.
“We look forward to working closely with the agency to bring AMT-130 to the
Huntington’s disease patient community as quickly as possible.”
As explained in the press release, Breakthrough Therapy
designation for AMT-130 means that the drug “may demonstrate substantial
improvement over available therapy on a clinically significant endpoint(s).”
The firm expects to provide a further FDA update this
quarter. In the third quarter, it aims to present data on AMT-130 to support
its potential drug application submission.