As a ‘biological being,’ I embrace science’s fight against disease

 

I am a biological being.

 

This phrase came to me about a decade ago, and I have been hoping to write about its meaning for a long time.

 

Now, with scientific research at key American institutions such as the National Institutes of Health and university labs under attack from the Trump administration, the phrase resonates with me stronger than ever.

 

From the time I was hospitalized in 1977 with two herniated discs after shoveling heavy snow through decades of participation in Huntington’s disease research studies, I have been acutely aware of my body as the object of biomedical observation.

 

Seeing scans of deteriorating HD brains at scientific conferences leaves me deeply worried about the shrinking of my own brain – the inevitable result of the fact that I carry the HD gene.

 

In March 2022 I observed preliminary data presented by Triplet Therapeutics from SHIELD-HD, a two-year research study of 70 presymptomatic and early-disease-stage carriers of the HD mutation. Triplet aimed to use SHIELD-HD to support plans for a groundbreaking clinical trial to attack a key driver of HD, somatic expansion, the mutant huntingtin gene’s tendency for continued expansion with age. The program was scuttled because the firm folded in October 2022 as it lacked investment funds.

 

The 2022 SHIELD-HD data showed deterioration in the brains of the gene carriers.

 

For the first time, I saw information about the impact of the HD gene on my own brain. I had volunteered for SHIELD-HD, undergoing MRI brain scans and cognitive tests and giving samples of blood and my cerebrospinal fluid (CSF) at the HD clinic at the University of California, San Diego.

 

Below are photos of me in the clinic in August 2022, just two months before the Triplet shutdown. The first shows a neurologist injecting an anesthetic to prepare for the drawing of my CSF. In the second photo the doctor draws a small amount of my CSF. It was the last of my several CSF drawings over the course of SHIELD-HD. Scientists see analysis of CSF, which bathes the brain, as a major tool in the search for therapies for HD. 

 

Having CSF drawn is a safe procedure but can be painful. Each time I drove home by myself within a couple hours of the drawing. I am very glad I did it.

 

 

 

 

Analysis of SHIELD-HD

 

With the end of Triplet, final analysis of the key SHIELD-HD data was completed by CHDI Foundation, Inc., the largest private funder of HD research. The analysis was presented at the 19th Annual HD Therapeutics Conference, sponsored by CHDI, in February 2024.

 

A future article will further explore my participation in SHIELD-HD and the importance of that program for HD research.

 

The 20th Therapeutics Conference: a sign of collaboration

 

As a biological being, I embrace science, not useless conspiracy theories. At the University of San Diego, where I teach and research, I began a new course this month called “A History of the Brain: Examining Huntington’s Disease.” One key lesson from the history of brain science: reliance on superstition was replaced with scientific observation – the key to solving neurodegenerative disorders like HD.

 

On a large scale, so has the HD community participated in and supported science – from the start of the hunt for the gene in the 1970s to programs today such as Enroll-HD. Tens of thousands of individuals from around the world have taken part, despite the fact that HD is a rare disease, with about 40,000 affected individuals in the U.S.

 

CHDI, the Huntington’s Disease Society of America, the Hereditary Disease Foundation, Help4HD International, and other HD organizations also rely on science and cooperate with scientific institutions.

 

A magnificent example of scientific collaboration will take place starting this evening in Palm Springs, CA, as the 20th HD Therapeutics Conference gets under way at the Parker hotel.

 

Stay tuned for reports about the meeting.

Savoring 20 years of my Huntington’s disease blog

 

This month I am celebrating the 20 years of this blog.

 

I began At Risk for Huntington’s Disease on January 10, 2005, wanting to “squeeze as much life into my days as possible” before experiencing the debilitating HD symptoms that led to my mother’s death a year later. Because I lived in what I called the “terrible and lonely HD closet” – fearful of genetic discrimination – I used the pseudonym “Gene Veritas,” “the truth in my genes.” That name reflected the fact that I had tested positive for the HD gene in 1999.

 

My mother died at 68, after two decades of debilitating symptoms, which was very painful to watch.

 

I turned 65 last month. By this age, I had expected to have full-blown HD, which would have left me unable to work, drive, or write.

 

But, according to my latest neurological checkup, I don’t yet have apparent HD symptoms!

 

In general, the more abnormal the gene, the earlier the age of disease onset. My mother and I have the same gene mutation, suggesting a similar disease path. However, although my mother’s symptoms started in her late 40s, one or more modifier genes, the functions of which were discovered a decade ago, have perhaps delayed my disease onset.

 

This article is number 336. Each day of good health is a blessing.

 

Gene Veritas (aka Kenneth P. Serbin) with his blog (photo by Regina Serbin)

 

The impact

 

In 2012, I exited the HD closet by publishing an essay – and using my real name, Kenneth P. Serbin – in The Chronicle of Higher Education. It was titled “Racing Against the Genetic Clock.” Going public opened new vistas of advocacy and enabled me to blog with greater transparency.

 

In December 2022. I published a detailed analysis of the blog in “Striving for a Realistic and Unapologetic View of Huntington’s Disease” in the Journal of Huntington’s Disease. It described how the blog has helped give voice to the HD community by exploring the major challenges faced by HD families, becoming a key reference for those families, and chronicling the quest to defeat the disorder.

 

As I observed, the blog has also “helped document the new and harrowing experience of living in the gray zone between a genetic test result and disease onset.”

 

At Risk for HD has addressed multiple topics including advocacy, caregiving, family trauma, coping strategies, genetic testing, discrimination, leaving the HD closet, participation in research and clinical trials, as well as religion, faith, and spirituality.

 

When my mother was diagnosed with HD in 1995 – two years after the discovery of the gene – little hope existed for treatments that could slow the progression of HD. However, in the past decade, advances in academic labs and biopharma firms have led to key clinical trials that show potential for affecting the course of HD and perhaps even a cure (click here to read more).

Telling the story of those complex developments has become a major focus of At Risk for HD. With the growing number of research projects, I have necessarily highlighted those that appear closest to producing actual drugs such as the Roche gene silencing program, which I have covered extensively.

 

In 2021, the first Roche trial showed lack of efficacy. In 2023 Roche started enrolling volunteers in a more focused trial to see if the drug might work at least in some patients. Other key trials are in progress or being planned.

 

Hoping for an HD-free world, savoring life

 

Writing the entries of At Risk for HD has given me great meaning and purpose, which researchers have identified as increasing well-being and positively impacting the course of the disease.

 

For now, I plan to continue blogging as long health permits – and until the quest for a cure is complete.

 

In February, I hope to attend the crucial 20th Annual HD Therapeutics Conference at the Parker Hotel in Palm Springs, CA. The conference is sponsored by CHDI Foundation, Inc., the largest private funder of HD research.

 

In 2011, I delivered the conference keynote speech before 250 scientists, physicians, and biopharma reps – a decisive step towards my complete exit from the closet in 2012 and chronicled in this blog.

 

I have described the conference as the “Super Bowl of HD research,” covered in many blog articles and videos of scientists (see, for example, this one).

 

With the rest of the HD community, I hope for the announcement of effective treatments. I very much look forward to reporting on progress.

 

Just as important is the need to savor life – another key lesson of my journey with the HD community, this blog, and my friends and family.

Exploring the unique qualities of INGREZZA, the newest FDA-approved drug for Huntington’s disease chorea

 

After the news last year that the U.S. Food and Drug Administration (FDA) had approved INGREZZA to treat chorea associated with Huntington’s disease, a debilitating movement disorder, I wanted to better understand the development of this drug and the unique qualities claimed by its creator.

 

On November 17 I interviewed company officials at Neurocrine Biosciences, Inc., which fashioned valbenazine – the chemical name for INGREZZA – in the early 2000s. In 2017, INGREZZA was approved by the FDA for the treatment of tardive dyskinesia, an irreversible involuntary movement disorder unrelated to HD. Neurocrine is in San Diego, one of the world’s leading biotech hubs and where I reside.

 

In an initial report on INGREZZA, including a Zoom interview with three Neurocrine officials, I noted the drug’s advantages over the two other FDA-approved chorea remedies, Xenazine (tetrabenazine) and Austedo (deutetrabenazine).

 

INGREZZA is easier to take, requiring just one daily dose in capsule form. Xenaxine and Austedo have long required multiple daily doses, although in May the FDA approved once-daily extended-release tablets for Austedo. Unlike the other drugs, INGREZZA also does not require titration, that is, slowly increasing the dosage over weeks. INGREZZA is always just one pill.

 

 

In contrast with the other drugs aimed at chorea, INGREZZA is a capsule – not a tablet – and is taken once daily even without an extended-release formulation. These characteristics potentially provide physicians and patients greater flexibility in dosing, because INGREZZA can be crushed and is available in three effective doses. As a result, Neurocrine’s drug, while indicated for oral administration, can also be crushed and mixed with food or provided through a feeding tube – often necessities for late-stage HD patients.

 

In April the FDA approved INGREZZA SPRINKLE capsules, a new formulation of the drug, in oral granules. Neurocrine developed this version of the drug for those with HD or tardive dyskinesia who experience difficulties in swallowing. It can be sprinkled on soft food. INGREZZA SPRINKLE offers the same three simple and effective dosing options (40 mg, 60 mg and 80 mg) as INGREZZA.

 

In last year’s interview, recognizing that INGREZZA only treats chorea, the Neurocrine officials stated that they plan to seek potential disease-modifying remedies that could potentially slow, halt, or reverse the progression of debilitating neurological conditions, which might include HD.

 

A substantial reduction in chorea

 

According to a Neurocrine press release (and also a June 2023 scholarly article in Lancet Neurology), INGREZZA decreased chorea severity three times better than a placebo.

 

So far researchers have not done a head-to-head study of Xenazine, Austedo, and INGREZZA. All three are VMAT2 inhibitors, designed to reduce involuntary movements of chorea. VMAT2 inhibitors help regulate dopamine, a chemical messenger in the brain that affects movements.

 

As my above-mentioned article stated, Dietrich Haubenberger, M.D., the executive medical director at Neurocrine and clinical lead for the firm on the successful Phase 3 KINECT-HD clinical trial leading to INGREZZA’s approval, called valbenazine a “unique molecule.”

 

Comparing INGREZZA with competitors

 

In 2015 I reported on the key differences between tetrabenazine (Xenazine) and its derivative deutetrabenazine (Austedo), which was also developed in San Diego.

 

During my November 2023 interview with Dr. Haubenberger and other Neurocrine scientists, I sought to better understand INGREZZA’s uniqueness and its benefits for HD-affected individuals. How does valbenazine contrast with tetrabenazine and its derivative deutetrabenazine?

 

The basics were described by Dimitri Grigoriadis, Ph.D., a pioneer of valbenazine and today a semi-retired distinguished scholar at Neurocrine. A neuropharmacologist by training, Dr. Grigoriadis started with the firm at its inception in 1993 and previously served as chief research officer.

 

Understanding the chemistry

 

Dr. Grigoriadis explained how INGREZZA works in the brain.

 

The “unique part of INGREZZA,” he said, is that it gets broken down by the body, then produces a single “isomer” that is a key metabolite of tetrabenazine. A metabolite results from the breaking down of a chemical.

 

“That is the chemical that binds to VMAT2, the protein, and blocks the entrance of dopamine” into relevant parts of brain cells, Dr. Grigoriadis added.

 

The drug discovery that Neurocrine did for valbenazine involved a drug profile that was highly selective for the VMAT2 protein, Dr. Grigoriadis recalled. “And through our research, we were able to identify a molecule that provides only the high affinity, very selective isomer of [the metabolites] of tetrabenazine.”

 

Comparing hands

 

Dr. Grigoriadis illustrated the concept of an isomer by noting how left and right hands resemble each other but are positioned differently.

 

“An isomer is a molecule that is exactly the same, has the same structural components,” he said. “So, it's an identical molecule, but it's left-handed, right-handed orientation. Your hands are four fingers and a thumb. They're identical, but they are in a different orientation.”

 

Isomers work in a similar way, he continued.

 

“They fit differently,” he said. “Functionally, they are different, even though they look exactly the same. You could have two isomers of the same molecule, a left hand and a right hand, that fit into different proteins, that fit into different spaces because they are in a different orientation.”

 

As a result, the various qualities of a drug “could be different,” he continued, resulting in a “slightly different” way in which the chemicals produced by INGREZZA “function.”

 

Dimitri Grigoriadis, Ph.D. (left), Dietrich Haubenberger, M.D., and Gene Veritas (aka Kenneth P. Serbin) discuss INGREZZA at the Neurocrine offices (photo by Aimee White, Director, Corporate Communications, Neurocrine). (Click on an image to make it larger.)

 

Building on tetrabenazine

 

At the time of valbenazine’s discovery, Neurocrine did not know whether it could help patients with diseases like tardive dyskinesia or HD, because the research on valbenazine had not been done, emphasized Eiry Roberts, M.D., Neurocrine’s chief medical officer. No drug had been developed for tardive dyskinesia before valbenazine.

 

“So this was a totally new research project,” Dr. Roberts continued. “There were learnings from experience with tetrabenazine that made it important to find out how valbenazine could be a safe and effective treatment for patients with conditions not sufficiently addressed by other medications available at the time.” The company also did extensive research to prove valbenazine’s safety, she added.

 

In addition, Neurocrine determined that, besides showing promise in the lab and efficacy in clinical trials for the treatment of tardive dyskinesia and chorea associated with Huntington’s disease, valbenazine could be mass-produced, Dr. Grigoriadis said.

 

Benefits for patients

 

Dr. Haubenberger stressed that INGREZZA is unique because  it involves just “one capsule, once daily with no complex dose adjustments to get to an effective dose.”

 

The once-a-day quality results from valbenazine’s “very long half-life of its effectiveness” (the time it remains in the body), explained Grace Liang, M.D., a movement disorders neurologist and Neurocrine’s vice president of clinical development in neurology.

 

“We know that the long half-life is important not only for the convenience this provides, but it allows patients to take it consistently without forgetting a dose,” said Dr. Liang. “Everybody has a life to live.” The “long duration” in the body and the selectivity – that it doesn’t act on other receptors of the brain that may cause other effects – make INGREZZA “special” for patients, she added.

 

INGREZZA “gives that nice, smooth, and steady coverage,” in contrast with the other chorea drugs, which have multiple daily doses and a shorter half-life, Dr. Liang continued.

 

INGREZZA also takes effect faster than Xenazine and Austedo, Dr. Haubenberger pointed out. He added that “with the first dose and as early as at two weeks of treatment, the clinical trial showed a greater reduction of chorea in patients on valbenazine compared to placebo.”

 

Unlike medicines that purposely have a material on their capsule to cause an extended release, valbenazine needs no such modification to achieve its “inherent,” smooth, once-daily effect, Dr. Roberts added.

 

Looking to the HD community

 

The FDA approved INGREZZA for use in adults with HD chorea. Neurocrine has no plans for a clinical trial of the drug in juvenile HD patients.

 

“We do recommend that people just use INGREZZA as it's labeled,” Dr. Liang said. “Obviously the care providers, the physicians would need to evaluate what the best treatment options are for those children, and we're hopeful that future developments can also support their needs as well.”

 

“Data is still being collected,” said Dr. Haubenberger, referring to an ongoing three-year study of more than 150 adults with HD taking INGREZZA. “There's lots more to learn about the compound itself and that's really where we want to invest in, where we can even learn more, share that with the community and even learn from that to inspire future avenues of research in HD and also other conditions.”

 

In these studies that reflect more “real-life settings, there’s much that can be learned from a broader data set than what could feasibly be done in a controlled clinical trial,” added Dr. Liang.

 

Other valbenazine projects

 

Previously, a Neurocrine clinical trial program of valbenazine for Tourette’s disorder did not show efficacy, Dr. Roberts said.

 

Neurocrine currently has a Phase 3 program for “valbenazine as an adjunctive treatment for schizophrenia, adjunctive to the antipsychotics that those patients take right now,” Dr. Roberts said. The drug is also in a Phase 3 study for the “commonest movement disorder in children, dyskinetic cerebral palsy,” she added.

 

In March Neurocrine announced the start of a Phase 1 clinical trial with their next-generation VMAT2 inhibitor, NBI-1065890, to study the safety and tolerability in healthy volunteers.

 

“We’re excited to bring this next-generation, internally discovered, highly potent, oral, selective VMAT2 inhibitor into the clinic with the hope of providing differentiated benefit in treating certain neurological and neuropsychiatric conditions,” Dr. Roberts stated in a press release. 

 

Gene Veritas (left) with Eiry Roberts, M.D., Chief Medical Officer, Neurocrine (photo by Aimee White, Neurocrine)

 

Aiming for disease-modifying therapies

 

Our November interview concluded with Dr. Roberts’ reflections on Neurocrine’s commitment to seek disease-modifying therapies for neurological conditions such as HD, including its new partnership with Voyager Therapeutics, a key player in the development of next-generation gene therapies. Voyager has experience in HD research.

 

“While symptomatic treatments are incredibly important for patients living with the diseases that we're seeking to serve, like Huntington's, for us to be a true innovator as well in this field, we need to be focused on understanding disease modification and cures,” Dr. Roberts said. “And so the collaboration with Voyager is one that gets us into the gene therapy space for potential curative or disease-modifying treatments. And we have other efforts that are very early in our research to look at different ways of coming upon disease modification.”

 

“It's really a focus area for us as we look at some of these novel platforms that we're coming forward with,” Dr. Roberts concluded.

 

Those research platforms are getting a boost: Neurocrine is moving to a new, state-of-the art 535,000-square-foot research campus. The lab space is scheduled for completion by year’s end.

 

Neurocrine's new research campus (photo courtesy of Neurocrine).

‘Striving for a cure’: highlights from the 19th Annual Huntington’s Disease Therapeutics Conference

 

Progress towards effective treatments for Huntington’s disease relies on the affected families’ collaboration with researchers exploring the frontiers of science.

 

The potentially pathbreaking findings featured at the recently completed 19th Annual HD Therapeutics Conference, sponsored by the nonprofit CHDI Foundation, Inc., led CHDI Chief Scientific Officer Robert Pacifici, Ph.D., to declare that the community will achieve therapies.

 

In this article I highlight the scientists’ work with a photo essay on their conference presentations and some of their key observations.

 

I cover most of the presentations. For detailed reports on the conference, see the articles in HDBuzz by clicking here, here, and here. Later CHDI will post videos of the presentations on its website. It is also preparing a video “postcard” of the event.

 

In recent decades, Huntington’s breakthroughs have resulted from the increasing amount of human data, which Dr. Pacifici and other scientists say is the best way to study the disease and develop potential therapies. The presentations at this conference especially reflected this trend. Researchers such as Matthew Baffuto, B.S., of the Heintz Lab at The Rockefeller University (in the photo above), recognized the importance of postmortem donations of HD-affected individuals’ brains and other human samples for their research. Baffuto’s final slide included a dedication: “To the HD patients and families who make this human research possible and for whom we continue to strive for a cure.” (All photos by Gene Veritas, aka Kenneth P. Serbin) (Click on an image to make it larger.)

 

The first wave of attempts by pharmaceutical companies to defeat Huntington’s has involved attempts to lower the amount of the abnormal huntingtin protein (HTT) in patients’ brains. In many of these approaches, this also means lowering the amount of normal HTT. The lab of Jeff Carroll, Ph.D., a scientist at the University of Washington and a HD gene expansion carrier like me, has extensively studied huntingtin lowering in mice. Normal huntingtin is necessary for adult mice to function, Dr. Carroll observed. Huntingtin lowering is not a “bad idea, just that there’s a floor between 50 percent and zero percent HTT,” he said.

 

Tony Reiner, Ph.D., of the University of Tennessee Health Science Center, presented the latest findings of his work comparing HD mouse brains to human tissue from deceased HD-affected individuals. He also focuses on how HD affects the various regions of the brain differently. This photo illustrates how Dr. Reiner uses antibodies to measure the complications that arise in HD mouse brains.

 

Sarah Tabrizi, M.D., Ph.D., of University College London, discussed her lab’s research on somatic expansion, the tendency of the abnormal huntingtin gene to expand with time and become more harmful to the brain. She presented data on developing drugs to interact with modifier genes, which can impact somatic expansion and therefore the age of disease onset. Dr. Tabrizi focused on the modifier gene MSH3 as an ideal therapeutic target. For this research, the Tabrizi lab has utilized stem cells, CRISPR gene editing techniques, and antisense oligonucleotides, used in huntingtin lowering drug programs and other HD research projects.

 

Ricardo Mouro Pinto, Ph.D., of Harvard University Medical School, presented his lab’s work on genetic modifiers of somatic expansion. Dr. Pinto has implicated the so-called DNA mismatch repair pathway as a critical driver of somatic expansion. His lab is also developing CRISPR-based strategies as potential therapies. Dr. Pinto’s team was recently awarded a grant from the Hereditary Disease Foundation to continue the search for therapies.

 

Mark D. Bevan, Ph.D., of Northwestern University, spoke on his lab’s latest findings in HD mice, in particular the dysregulation and rescue of subthalamic nucleus, involved in the suppression of movement. Dr. Bevan highlighted the need for both huntingin-lowering and somatic expansion therapies to have widespread delivery into the brain.

 

Osama Al-Dalahmah, M.D., Ph.D., of the Columbia University Irving Medical Center, discussed the major role of astrocytes in HD. There are over 100 different brain cell types. Astrocytes are cells that provide physical and chemical support to other cells such as neurons, key in the brain. As a neuropathologist, Dr. Al-Dalahmah analyzes post-mortem brain tissues. Among other observations, he noted that astrocytes can be neuroprotective. His lab is working on ways to protect neurons in HD.

 

Scientist Baffuto’s wide-ranging presentation focused on specifying cell types in unraveling both the molecular mechanisms underlying somatic expansion and also the path of the disease. The Rockefeller team developed what it describes as an “innovative methodology” for deep profiling of cellular processes in the brain. The technique is fluorescence-activated nuclear sorting (FANS). As shown in one of Baffuto’s slides, they used FANS to detail the disease process in key areas of postmortem HD-afflicted brains: the striatum, cortex, thalamus, hippocampus, amygdala, and cerebellum.

 

Scientists continue to debate exactly what triggers Huntington’s. Assessing the impact of somatic expansion, the Harvard University Medical School team studying HD proposed a new model for how somatic expansion contributes to HD pathology. Bob Handsaker, B.S., explained that, until recently, scientists thought that the DNA triplet repeat creates a toxic protein whenever the CAG repeat length is greater than 40 and that HD pathology arises from lifelong exposure to this toxic protein, similar to how smoking damages the lungs. (The abnormally repeated DNA word CAG is the genetic root of HD.)

 

New research has challenged this idea in three important ways: First, there is much more somatic expansion than had been appreciated, with affected neurons expanding to reach over 400 CAG repeats. Second, this somatic repeat expansion starts slowly and then accelerates over time, like a "slowly ticking DNA clock” in each individual neuron. Third, the evidence suggests that modest somatic expansion, up to a repeat length of 150 CAGs, does not create a protein that is toxic - the toxic effect in each individual neuron only begins above this longer repeat-length threshold. Along with other research presented, this finding underscored that there may be a longer window of opportunity than had previously been appreciated for any therapeutic interventions that act to slow or block somatic expansion. This is because in the first few decades of life in a person with HD, the DNA in most neurons has typically not expanded to reach this toxic threshold.

 

Darren G. Monckton, Ph.D., of the University of Glasgow, presented his new research on biomarkers, signs of a disease and indicators of whether a drug has efficacy. Dr. Monckton focused on biomarkers in areas of the body outside the brain such as blood, in particular regarding the degree of somatic expansion and measuring it over time.

 

Carlos Bustamente, Ph.D., a Venezuelan American geneticist and the founder and CEO of Galatea Bio, Inc., advocated for enabling precision medicine around the globe. Dr. Bustamante observed that new technological advances have made it faster and less expensive to understand human genomes but most of such resources have gone to understanding predominantly northern European communities. He pointed out the need to expand the genetic dataset to other parts of the globe. Dr. Bustamante also explained how genetic differences in the global population have contributed to differences in the geographic prevalence of Huntington's.

 

David Margolin, M.D., Ph.D., the vice president for clinical development at uniQure, presented an update on the early-stage (Phase 1/2) clinical trial of the company’s gene therapy drug, AMT-130, involving 39 trial volunteers in the U.S. and Europe. Dr. Margolin reported that, relative to baseline, volunteers treated with AMT-130 showed evidence of preserved neurological function. So far, the drug has proved to be safe.

 

Amy-Lee Bredlau, M.D., the senior medical director at PTC Therapeutics, presented interim safety and biomarker data for the company’s huntingtin-lowering pill, PTC-518, in PIVOT-HD, a Phase 2 trial. At this stage, the drug has been shown to be safe and has achieved a lowering of huntingtin in the blood – although data do not yet show whether the lowering is also occurring in the brain.

 

From left to right, Roche researchers Jonas Dorn, Ph.D., Peter McColgan, M.D., Ph.D., and Marcelo Boareto, Ph.D., reanalyzed the data from the firm’s first attempt at a Phase 3 huntingtin-lowering trial program, which in 2021 ended without the drug tominersen showing the necessary efficacy for approval as a drug. The scientists discussed ways to improve clinical trial design, including for GENERATION HD2, a less ambitious, Phase 2 trial of tominersen in a smaller number of volunteers. GENERATION HD2 is in progress.