CHDI’s chief scientist: ‘Not a time for the Huntington’s community to rest on its laurels’

Given the unprecedented interest from biopharmaceutical firms and broadening range of approaches to attacking the disease, the need for the Huntington’s disease community to participate in research studies and clinical trials is “exploding,” CHDI’s head scientist said at the organization’s 14th Annual HD Therapeutics Conference yesterday.

“This is not a time to rest on our laurels,” said Robert Pacifici, Ph.D., the chief scientific officer for CHDI Foundation, Inc., the nonprofit virtual biotech dedicated to finding HD treatments. “Trials won’t go forward without people willing to take the risk of taking a drug never taken before.”

Dr. Pacifici’s comments came in an interview with me at the conference venue, the Parker Palm Springs hotel in Palm Springs, CA. The gathering of scientists, pharma executives, and advocates ends today.

Critical new research studies

The conference comes just after news of the start of Roche’s historic Phase 3 gene-silencing clinical trial and other clinical trial programs (click here to read more).

“It’s exciting times,” Dr. Pacifici observed. “Now more than ever we need to make sure that these channels of communication between patients and caregivers and researchers remain open and clear so that everybody knows what’s going on.”

With the advent of more trials, both the pace and number of research projects requiring volunteers is growing rapidly, he explained. One involves a forthcoming brain imaging study (using a PET-ligand).

To help understand the disease and measure the effect of potential drugs in clinical trials, scientists need to find more biomarkers (signals of the disease) in humans. For years, they have collected samples of blood. More recently, they started examining the cerebrospinal fluid and saliva.

Now CHDI wants to collect semen, Dr. Pacifici said. “There are certain things that happen only in those cell types that are going tell us what happens to Huntington’s DNA, and that’s going to be really critical for our efforts as well,” he explained.

CHDI will also establish a “Brains for HD” initiative to request donations of that organ from deceased individuals, Dr. Pacifici added. “Invaluable,” he said of the importance of brains in HD research. “Especially the rare young brain, if somebody happens to pass away from something else, and we can harvest the brain before it experiences the ravages of Huntington’s disease.”

You can watch my interview with Dr. Pacifici in the video below.

Not a time for the Huntington's community to rest on its laurels from Gene Veritas on Vimeo.

‘Huntington’s homework’

Dr. Pacifici outlined the conference’s three major areas of focus.

He described the first as “Huntington’s homework.”

“We might not like it, and it might be tough, and it requires some dedication, but we still have basic research to do to understand the underlying pathophysiology of Huntington’s,” he explained. “There are still some fundamental questions about what’s broken in HD that we need to understand, because until you understand what’s broken, it’s hard to fix it.”

To that end, this year’s conference talks have included topics such as HD’s hampering of the brain’s ability to repair itself and the loss of white matter in presymptomatic gene carriers like me.

Modifier genes: a key discovery

A second area involves the discovery of so-called modifier genes – a major advance only made possible with the participation in the research of 9,000 HD family members.

“We now know there are other genetic factors that influence, for any given CAG [the length of the genetic coding for the huntingtin gene], whether you’ll get the disease sooner or later,” Dr. Pacifici noted. 

People with same gene length can get the disease decades earlier or later, he said. “That’s a really big range, and what we’ve found is that the propensity to get it earlier or later is also heritable.”

The modifier genes affect onset by as much as a dozen years or more, he added.

“Imagine if we could make a drug that did the same thing – or did it even better,” Dr. Pacifici said. CHDI and HD scientists are at work on this task.

‘A wonderful time for HD research’

A third major aspect of the conference concerns “genetically identified targets” that are changed in people because of HD. This type of lab research is still in the early stages, Dr. Pacifici observed. However, these targets might also serve as models for drug design.

Dr. Pacifici noted that in the relatively mature field of “huntingtin lowering” – the approach of the Roche drug and of several other companies present at the conference – something “unthinkable” five years ago has occurred: the possibility of a “small molecule” drug. Such a drug would be taken orally, thus avoiding the spinal taps and other highly invasive procedures currently envisioned for these drugs. 

On February 26, Anuradha Bhattacharyya, Ph.D., of Ireland- and U.S.-based PTC Therapeutics presented a paper on the company’s efforts to develop such a drug.

As a nonprofit, CHDI’s job is to provide all firms access to the necessary biotechnological tools they need and to potential volunteers for studies and trials, Dr. Pacifici said. CHDI has spent hundreds of millions of dollars in the effort to treat HD, including grants to scientists and companies.

He concluded: “It’s a wonderful time to be a researcher in the area of Huntington’s drug discovery and it will soon be an opportune time to engage the broader patient community, because we really need your help.”

(Future articles will discuss other aspects of the meeting. For additional coverage, visit HDBuzz.net.)

Continued progress, but also caution, in the fight against Huntington’s disease

CHDI Foundation’s 14th Annual Huntington’s Disease Therapeutics Conference gets under­­ way today in Palm Springs, CA, in the wake of key developments in the search for the first HD treatments.

On January 28, pharma giant Roche announced that it had enrolled the first participant in GENERATION HD1, its historic global Phase 3 clinical trial of a gene-silencing drug that, if successful, could slow, halt, and perhaps even reverse HD symptoms. (Click here to read the announcement to the HD community by Roche ).

In the coming months, Roche aims to enroll a total of 660 clinical trial volunteers in 15 countries. They will receive either the drug (called RG6042) or a placebo in monthly spinal taps over 25 months.

The start of the trial comes less than a year after the presentation of the impressive Phase 1 trial results at last year’s Therapeutics Conference. RG6042 significantly reduced the levels of the mutant huntingtin protein in the cerebrospinal fluid of the clinical trial volunteers. Because of those results, Roche took the unusual step of skipping a Phase 2 trial and going directly to Phase 3.

Roche’s announcement follows a record year for new drug approval by the U.S. Food and Drug Administration (FDA), with 59 drug approvals overall, noted George Yohrling, Ph.D., the senior director of mission and scientific affairs for the Huntington’s Disease Society of America (HDSA). The previous record was 53 in 1996.

Of last year’s approvals, 34 involved orphan conditions like HD (fewer than 200,000 patients) – a sign, said Dr. Yohrling, that the pharmaceutical industry has not ignored those disease communities. He spoke in a January 16 webinar reviewing progress in HD research in 2018.

Roche to buy Spark

On February 23, The Wall Street Journal reported that Roche had agreed to pay $4.8 billion to acquire Spark Therapeutics, Inc., a Philadelphia-based biotech firm focusing on gene therapy approaches to genetic diseases, including HD. Spark’s co-founders include HD researcher Beverly Davidson, Ph.D.

With a record 360 participants from around the world, the CHDI conference opens this evening at the Parker Palm Springs hotel and runs through February 28. At the conference, I hope to obtain comment from Roche officials about how the acquisition could potentially expand Roche’s approaches to treating HD. Spark has engaged in pre-clinical HD research.

Above, scientists visit the CHDI Resource Fair at the 14th Annual HD Therapeutics Conference. Below, Gene Veritas (aka Kenneth P. Serbin) at the Parker Palm Springs (photos by Gene Veritas).

Exciting announcements about other trials

On January 22, the Dutch-American company uniQure announced that it had received approval from the FDA to start the first-ever HD clinical trial that uses a virus injected into the brain carrying a gene therapy agent to reduce the amount of harmful huntingtin protein. Viruses are used in vaccines and to treat cancer. They are under study for use in HD and other diseases. 

Unlike Roche’s RG6042, which would require long-term and probably lifelong treatment, uniQure’s gene therapy could permanently fix the problem of HD by “altering human DNA or inserting new genetic instructions into human cells,” observed HDBuzz.

However, it also noted that “gene therapy is a high-risk high-reward strategy. The benefits could be long-lasting – but so could any side effects.”

In this Phase 1/2 clinical trial, uniQure will primarily test safety and tolerability but also whether its drug is working as designed. It plans to start enrolling clinical trial volunteers in the U.S. in the second half of this year.

In late January, the California Institute for Regenerative Medicine (CIRM), the state’s voter-approved multi-billion stem cell initiative, announced a $6 million grant to prepare the way for a potential HD stem cell clinical trial. CIRM awarded the grant to the lab of Leslie Thompson, Ph.D., of the University of California, Irvine. The therapy could involve the transplanting of stem cells converted into neural (brain) stem cells shown in HD animal models to improve the function of compromised brain cells.

"Based on our pre-clinical studies in mice, human neural stem cells are highly beneficial, reducing the accumulation of a toxic form of the mutant huntingtin protein and improving HD symptoms and impaired electrical currents in the brain," Dr. Thompson explained in a news release.

FDA delays Wave trials

Another company’s plans have been slowed. The FDA has delayed two Phase 1 clinical trial by Wave Life Sciences using a drug – an antisense oligonucleotide – similar to Roche’s RG6042.

Whereas RG6042 reduces the amount of both mutant and normal huntingtin protein, Wave’s drugs target only the mutant.

“In the United States, we received approvals to proceed with the single-dose portions of both trials,” a February 6 Wave prospectus states. “However, the FDA indicated to us that we cannot progress to the multiple-ascending dose portions of these trials in the United States unless we conduct an additional preclinical [animal] study and present the resulting data to the FDA for its review.”

Realistic expectations

The news about Wave might be a cautionary tale for the HD community about realistic expectations. Only ten percent of clinical trial projects result in a drug reaching the market.

Alzheimer’s disease is another case in point. Over the past ten years, all 25 Alzheimer’s clinical trials have failed, noted Jody Corey-Bloom, M.D., Ph.D., the director of the HDSA Center of Excellence at the University of California, San Diego (UCSD), during her annual HD research update last October at the local HD support group.

As Dr. Corey-Bloom explained, most of those Alzheimer’s trials successfully removed seemingly harmful plaque from the brain, but they didn’t cure the disease. 

Such plaque isn’t a factor in HD, however, perhaps increasing hope that the Roche Phase 3 trial has a better chance of producing effective results, she observed. Dr. Corey-Bloom’s well-regarded UCSD clinic is one of the sites for GENERATION HD1.

An end to the ‘wait and see’?

In her presentation, Dr. Corey-Bloom addressed several of the key questions about GENERATION HD1 that have emerged in the HD community, including concerns about the injection of the drug by spinal tap (lumbar puncture).

She noted that spinal taps are a regular part of treating a condition known as pseudotumor cerebri, which produces severe headaches and, if left untreated, blindness. Patients get monthly spinal taps.

“We’ve had people that have probably done lumbar punctures monthly for several years, and they seem to do okay,” she commented.

She was optimistic that, if GENERATION HD1 is successful, Roche and physicians will seek alternatives to spinal taps. They will also pursue expanding access to the drug to presymptomatic gene carriers, she added. (That includes me.)

Dr. Corey-Bloom ended on a positive note.

“I’m always talking about things that will eventually come,” said of previous talks, in which she has cautioned the HD community against unwarranted enthusiasm. “Now we actually have clinical trials, and we have clinical trials that look like they are going to be effective. That’s probably the strongest statement that I’ve made, because I’m always trying to tell people, ‘Let’s just wait and see.’”

However, with the Alzheimer’s trials in mind, Dr. Corey-Bloom also reminded the audience that there is no guarantee GENERATION HD1 will actually affect the disease.

She crossed her fingers for good luck. We in the HD community will need to continue our hard work collaborating with her and the many other researchers engaged in the quest for treatments.

You can watch Dr. Corey-Bloom’s presentation in the video below.