Most cancer deaths are caused by metastasis, but how cancer cells and tumors modify themselves and spread from their origins to other parts of the body remains largely a mystery — and fundamentally challenging.

In a new paper published December 6, 2024 in Science Advances, study co-author Sanju Sinha, PhD, assistant professor in the Cancer Molecular Therapeutics Program at Sanford Burnham Prebys, and colleagues, investigate whether primary and metastatic tumors more closely resemble the tissues of origin or target tissues in terms of gene expression.

Their findings suggest movement and evolution, providing a comprehensive transcriptome-wide view of the processes through which cancer tumors adapt to their metastatic environments before and after metastasis.

Sushmitha Vallabh, a senior lab manager at Sanford Burnham Prebys, was recognized for her outstanding contributions by Lab Manager magazine during the publication’s celebration of Lab Manager Appreciation Month in October 2024.

The magazine encouraged readers to nominate peers who demonstrate exceptional leadership in their labs. The team behind the publication also plans virtual and in-person professional development events for lab managers, as well as offers digital learning and certificate programs through The Lab Manager Academy.

Vallabh works in the lab of Carl Ware, PhD, a professor in the Immunity and Pathogenesis Program at Sanford Burnham Prebys. We caught up with Vallabh to discuss this national recognition.

How did you enter the field of lab management?

Before joining Sanford Burnham Prebys, I was at the Cincinnati Children’s Hospital Medical Center. I completed a master’s degree there and then joined the lab I had trained in as a staff member.

I was in that lab for close to four years, and during that time it grew considerably. One of the senior research technicians left, so I took over some of the lab management tasks, such as ordering supplies and making sure protocols were in place.

When I moved to San Diego and applied for a research technician job at my current lab, we ended up discussing my lab management experience. The lab also had a need in that area, so I ended up joining as a lab coordinator in 2020 and being promoted to lab manager the following year.

What do you like most about your role?

I like it when I’m able to solve problems. Every day, I discuss a variety of issues with any number of lab members. I try my best to find solutions for everyone, and it is always fulfilling to be able to answer questions and resolve challenges.

What did it mean to you to be selected for this honor?

I was very, very surprised, but in a good way. It felt especially rewarding because I’ve been following Lab Manager magazine for quite some time now. It is a great organization that provides professional development opportunities for lab managers, so it is nice to be honored by a group doing important work in the field.

What is the most important trait or skill you can help foster to make a lab more successful?

I think training is crucial. Even when new lab members join that have significant research experience, all labs and organizations are different. It is important to train new members on lab standards and protocols in order to set each individual within the lab up for success.

What is the top piece of advice you would give to someone considering entering your field?

Not to react quickly or jump to conclusions. Disagreements and conflicts will happen, and it is always important to talk to everyone involved before determining how best to resolve the situation.

Is there anyone you would like to acknowledge that helped you achieve this honor?

Zumi Alvarado is a lab coordinator at Sanford Burnham Prebys. I have trained her on our standards and protocols to facilitate collaboration between our labs. She thought there were practices she could adapt to her own team, so that must be why she nominated me for this award. It was thoughtful of her to put me in the running for this recognition.

I’m also grateful to Carl as my principal investigator. He has full faith in me, and he’s always there to help if I reach out about a problem. Also, I’d like to thank Paula Norris, the Ware lab’s lab director when I was hired. She was a wonderful mentor as I was learning about the lab.

More than 25 years after targeting a member of this superfamily of proteins led to groundbreaking treatments for several autoimmune diseases including rheumatoid arthritis and Crohn’s disease, San Diego scientists note a resurgence of interest in research to find related new drug candidates.

In 1998, the same year “Footloose” debuted on Broadway, REMICADE® (infliximab) was approved by the FDA for the treatment of Crohn’s disease. This was the first monoclonal antibody ever used to treat a chronic condition, and it upended the treatment of Crohn’s disease.

Research published in February 2024 demonstrated better outcomes for patients receiving infliximab or similar drugs right after diagnosis rather than in a “step up” fashion after trying other more conservative treatments such as steroids.

Infliximab and ENBREL® (etanercept) — also approved in 1998 to treat rheumatoid arthritis — were the first FDA-approved tumor necrosis factor-α (TNF) inhibitors. TNF is part of a large family of signaling proteins known to play a key role in developing and coordinating the immune system.

The early success of infliximab and etanercept generated excitement among researchers and within the pharmaceutical industry at the possibility of targeting other members of this protein family. They were interested in finding new protein-based (biologics) drugs to alter inflammation that underlies the destructive processes in autoimmune diseases.

As “Footloose” made it back to Broadway in 2024 for the first time since its initial run, therapies targeting the TNF family are in the midst of their own revival. Carl Ware, PhD, a professor in the Immunity and Pathogenesis Program at Sanford Burnham Prebys, and collaborators at the La Jolla Institute for Immunology and biotechnology company Inhibrx, report in Nature Reviews Drug Discovery that there is a resurgence of interest and investment in these potential treatments.

“Many of these signaling proteins or their associated receptors are now under clinical investigation,” said Ware. “This includes testing the ability to target them to treat autoimmune and inflammatory diseases, as well as cancer.”

Today, there are seven FDA-approved biologics that target TNF family members to treat autoimmune and inflammatory diseases. There also are three biologics and two chimeric antigen receptor (CAR)-T cell-based therapies targeting TNF members for the treatment of cancer. This number is poised to grow as Ware and his colleagues report on the progress of research and many clinical trials to test new drugs in this field and repurpose currently approved drugs for additional diseases.

“The anticipation levels are high as we await the results of the clinical trials of these first-, second- and — in some cases — third-generation biologics,” said Ware.

Ware and his coauthors also weighed in on the challenges that exist as scientists and drug companies develop therapies targeting the TNF family of proteins, as well as opportunities presented by improvements in technology, computational analysis and clinical trial design.

“There are still many hurdles to get over before we truly realize the potential of these drugs,” noted Ware. “This includes the creation of more complex biologics that can engage several different proteins simultaneously, and the identification of patient subpopulations whose disease is more likely to depend on the respective proteins being targeted.

“It will be important for researchers to use computational analysis of genetics, biomarkers and phenotypic traits, as well as animal models that mimic these variables. This approach will likely lead to a better understanding of disease mechanisms for different subtypes of autoimmune conditions, inflammatory diseases, and cancer, enabling us to design better clinical trials where teams can identify the appropriate patients for each drug.”

Nearly 30 years of discoveries by a Sanford Burnham Prebys scientist and collaborators lead to federal approval of the first non-steroidal drug to treat Duchenne muscular dystrophy.

For one San Diegan scientist at Sanford Burnham Prebys, the March 2024 federal approval of a new drug to treat Duchenne muscular dystrophy (DMD) marked a milestone in three decades of studying muscle regeneration and muscle-wasting diseases.

The compound, called Givinostat and marketed as DUVYZAT™, is a histone deacetylase inhibitor (HDACi) and was approved by the FDA for the treatment of boys with DMD.

“I have been working from the very beginning of my research career to translate early, basic discoveries into a treatment for DMD,” said Pier Lorenzo Puri, MD, director and professor in the Development, Aging and Regeneration Program at Sanford Burnham Prebys. “The lack of effective treatments for boys with DMD has left families and patients hopeless since the discovery of this disease. Witnessing the progression of such a disease without any option to counter its progression is cruel and I felt the urgency to help these people.”

DMD is the most frequent form of muscular dystrophy affecting approximately 1 in 3,500 male births. DMD is linked to the chromosome X, which harbors the gene coding the protein called dystrophin. As such, the disease develops only in males receiving from their mother the X chromosome carrying mutations in the dystrophin gene that impair production of dystrophin. Dystrophin is a protein that protects muscles from degeneration after they contract and relax. In its absence, the muscles of boys with DMD are prone to damage and undergo cycles of contraction and degeneration that eventually lead to muscle wasting and reduced function.

For decades, steroids have provided the standard-of-care for DMD, but steroids represent an empirical and palliative treatment based on their general anti-inflammatory properties, rather than a treatment that targets specific pathological events that contribute to DMD progression. Moreover, the chronic use of steroids is complicated by many side effects, including weight gain, weak bones, high blood pressure and behavior changes.

Puri decided to focus on the potential use of HDACi to treat DMD after he made seminal basic discoveries that revealed how muscle growth and regeneration are regulated by two enzymes with opposing activities: histone acetyltransferases and deacetylases.

“HDACi are not going to cure muscular dystrophy, but they do provide the first pharmacological treatment that can delay DMD progression, regardless of the type of mutation, and do so in a financially affordable way,” said Puri.

“It is important to note that FDA approval of Givinostat is not the end of the journey, but the beginning. The very good news here is that there is room to improve the efficacy of HDACi-based treatment for DMD by using already existing compounds or by developing novel molecules endowed with an improved therapeutic potential. This is because Givinostat has been used at sub-optimal concentrations due to potential adverse effects, and this might have limited its efficacy as a HDACi.

“People ask me whether Givinostat was approved because it is the most effective molecule among existing HDACi. The answer is that Givinostat has been the first, and so far the only, HDACi to be tested in clinical trials for boys with DMD. Givinostat might not entirely express the therapeutic potential of HDACi for DMD. A reasonable and exciting goal of future studies is to identify HDACi that surpass Givinostat in terms of therapeutic efficacy.”

Puri noted that, “It is also important to carefully investigate functional interactions between HDACi and steroids, as the clinical trial with Givinostat has been performed while research participants were receiving steroids. However, because the activity of steroids is largely dependent on HDAC, it is very likely that these two treatments could collide, rather than synergize in producing beneficial effects on the muscles of DMD boys.”

He also emphasized that the impact of FDA approval of Givinostat extends way beyond the possibility to offer a treatment for DMD.

“It is the first evidence that it is possible to treat DMD by targeting pathogenic events induced as a consequence of dystrophin deficiency, as an effort parallel to gene and cell therapy, which will hopefully converge into future and more effective combined therapies.”

Building the basic science foundation

Puri’s contributions to the approval of the first non-steroidal drug to treat DMD span nearly 30 years of basic and preclinical research of diseases thought to be incurable — especially pediatric conditions he thought especially cruel.

The puzzle pieces began to take shape as Puri was studying the growth of muscle cells and skeletal muscle tissue, a biological process called skeletal myogenesis. He started working on this project in the 1990s in the laboratory of molecular biology directed by Massimo Levrero, MD, in Rome. Puri had earned his medical degree in 1991 before conducting an internship in Internal Medicine.

“I started there, in a lab inside a hospital in Rome,” said Puri. “I used to see patients until the early afternoon and then I was running to the lab to perform experiments. As a young clinician with a passion for basic research, I was always developing experiments with patients in mind.”

Puri decided to test his first hypothesis by using what was then an innovative technology called microinjection to insert DNA or antibodies inside cultured cells. He decided to spend several months at the Free University of Berlin in the laboratory of Adolf Graessmann, PhD, a pioneer of this technique. Puri later decided to go to the United States to work in the lab of Jean Y.J. Wang, PhD, at the University of California San Diego, to further develop his studies.

After entering the U.S., Puri has worked closely with his long-term collaborator and friend Vittorio Sartorelli, MD, currently the deputy scientific director of the National Institute of Arthritis and Musculoskeletal and Skin Diseases and chief of the institute’s Laboratory of Muscle Stem Cells & Gene Regulation. Together, they uncovered an important role for two groups of enzymes, histone acetyltransferases and deacetylases, that control access to DNA by altering the structure of chromatin.

Histone acetyltransferases control DNA accessibility by adding acetyl groups to histones, which loosens the wrapping of DNA around them, essentially ‘opening’ chromatin and promoting gene expression. Histone deacetylases reverse the process by removing acetyl groups, limiting the activity of genes and the production of key proteins.

“One of our seminal findings was the discovery of associations between myogenesis and an enzymatic activity that could be pharmacologically modulated,” explains Puri.

Puri and Sartorelli started to explore the possibility that pharmacological modulators of this process by HDACi could affect the growth of muscle cell progenitors and their ability to form contractile muscle tissues.

After finding that HDACs limit muscle cell differentiation, the team’s next step was to find compounds (inhibitors) capable of blocking HDACs from removing acetyl molecules and reducing myogenesis. “We decided see if there is an HDAC inhibitor — an inhibitor of the inhibitor — because this could reduce muscle loss,” notes Puri. “There were a few compounds, and we found a strong effect every time we tested them.”

“I remember vividly the first time I saw the effect of HDACi on cultured muscle cells. I was a postdoc in Jean Wang’s lab at UC San Diego, and one morning I opened the incubator and found that muscle cells treated with HDACi had formed giant myotubes (the contractile muscle). Of course, we started to wonder whether such evidence could provide the rationale we were looking for. If so, this could pave the way toward discovering pharmacological interventions that may promote muscle regeneration.

“But, at that time, it sounded more like a dream. We did not even dare to imagine that the final outcome would have been the identification of a pharmacological treatment for DMD.”

Pursuing the preclinical potential

Puri and Sartorelli pursued their dream, driven by encouraging experimental evidence and discoveries. Still, it took years to provide the rationale for testing HDACi in DMD—years and a few fortunate coincidences. One was the identification of follistatin as a mediator of the action of HDACi on muscle cells. Follistatin is the endogenous inhibitor of myostatin, a potent inhibitor of muscle growth and size, ensuring that muscles do not grow too large.

It was during that time that other groups independently discovered that genetic mutations in the myostatin gene resulted in an abnormal increase in muscle mass in cattle, mice and humans. More importantly, it was published that genetic or pharmacological inactivation of myostatin could exert beneficial effects in a mouse model of DMD.

“That discovery suggested the rationale of testing whether HDACi could exert similar beneficial effect in the same mouse model of DMD,” said Puri. The team hypothesized that this could be achieved by using HDACi to block myostatin activity through the induction of follistatin.

Puri and Sartorelli decided to treat mdx mice — the mouse model of DMD — with a few HDACi. Puri performed these studies with a group of investigators that worked synergistically in his two labs (one in San Diego and the Dulbecco Telethon Institute laboratory in Rome) and in collaboration with Italian scientists Carlo Gaetano, PhD, and Claudia Colussi, PhD.

“The results of the experiment went beyond the most optimistic expectations,” said Puri. “The muscles were bigger. There was no scar tissue, no abnormal fatty deposits and less inflammation. The treated mice were running like normal mice.”

Puri and his collaborators published results in Nature Medicine in 2006 demonstrating significant improvements in muscle composition and exercise performance.

In follow-up studies, Puri and collaborators realized that the therapeutic properties of HDACi extended beyond the targeting of follistatin/myostatin interactions. The pace of discoveries increased along with the improved knowledge on DMD pathogenesis. Key and timely information was gained through identification of a population of muscle interstitial cells, called fibro-adipogenic progenitors (FAPs), from the laboratories of Fabio Rossi, MD, PhD, at the University of British Columbia in Canada and Dr. Kunihiro Tsuchida, MD, PhD, at Fujita Health University in Japan.

FAPs support muscle regeneration of normal muscles, but in dystrophin-deficient muscles these cells turn into the main effectors of fibrotic scars and fat infiltration — the most deleterious events in DMD pathogenesis. Studies from the Puri lab demonstrated that HDACi could restore the ability of FAPs from DMD muscles to promote regeneration, while blocking their pro-fibrotic and adipogenic activity.

“The identification of FAPs was a lucky coincidence, as it provided one of the main cell types targeted by HDACi and enabled the identification of the molecular mechanism of action that accounts for the therapeutic properties of HDACi,” said Puri.

“It also helped to set in our preclinical studies the parameters that have been used in clinical trials. Indeed, I believe that one of the reasons for the success of this journey has been the development of a solid scientific rationale. I was definitely fortunate to have worked with a team of incredibly skilled young scientists that shared with me the wish to help DMD patients and the perseverance to take on a challenge for over 20 years. Overall, discovering the MOA of HDACs has been a fantastic journey.”

“Although the evidence that HDACi could be used to treat DMD was strong and the rationale was very solid, it was hard to convince big pharma to invest on this treatment. There were many excellent HDACi in the market that could have been used, but after knocking on many doors, no one was willing to partner on this task.

Puri felt compelled by these results to keep building support to convince potential industry partners to develop clinical trials. After talking with many businesses, he found Italfarmaco, an Italian pharmaceutical company with an HDAC inhibitor called Givinostat.

“In the end, I had to knock on the door of Italfarmaco, which owned Givinostat — an HDACi that I had never tested in my previous preclincial studies. This was another coincidence since Dr. Christian Steinkulher, a friend and colleague, alerted me about the potential availability of a pan-HDACi called Givinostat from Italfarmaco.

“When I approached Italfarmaco, I immediately realized that they were not very well prepared to take on this type of research. They were not familiar with DMD, and they didn’t have any previous experience on muscular diseases. They also had no background on the epigenetic effects of Givinostat.

“Until that time, they used Givinostat mostly for its anti-inflammatory properties, rather than the epigenetic regulation of gene expression. However, Italfarmaco recognized some potential in this operation and decided to give to me the opportunity to perform preclinical studies with Givinostat for DMD.”

Clinical trials and regulatory approval

After additional preclinical studies to better understand how Givinostat worked, Italfarmaco informed Puri that the company was ready to develop a clinical trial.

The results of the phase II clinical trial were published in Neuromuscular Disorders in 2016. During the trial, the scientists looked at whether the composition of the muscle improved. Muscle biopsies taken from 19 subjects who were treated for more than a year demonstrated that the drug had caused an increase in muscle fiber area and a decrease in fat deposition, scar tissue and other hallmarks of DMD.

“It was remarkable to see that the same positive effects observed in mdx mice treated with HDACi were also observed in DMD boys treated with Givinostat,” noted Puri. “The reproducibility of the outcomes in preclinical studies and clinical trials emphasizes the importance of performing accurate preclinical studies and identifying reliable outcome measures, as we did with HDACi for DMD.”

The trial also helped the team determine what dose of Givinostat was safe and still effective to use in the pivotal phase III trial that was reviewed by the FDA before the agency granted approval.

Italfarmaco established ITF Therapeutics in January 2024 as a new division that is now responsible for marketing DUVYZAT™ in the U.S. ITF Therapeutics announced that the drug was available in the U.S. on July 25. Italfarmaco’s Marketing Authorization Application (MAA) for Givinostat to the European Medicine Agency (EMA) was validated in fall 2023. This means that the drug is eligible to be reviewed by the EMA. If approved, Givinostat can be made available throughout the European Union (EU).

Paving the way forward

Puri is not resting on his laurels and the approval of the first non-steroidal drug to treat DMD.

“Right now, we have steroids, HDAC inhibitors and gene therapy. We are working on the idea that gene therapy and HDAC inhibitors without steroids can perfectly synergize.”

The researchers are also investigating ways to enhance the effect of HDAC inhibitors through the use of extracellular vesicles (EV) released from FAPs following the exposure to HDACi. EVs are small biological bubbles that the body uses to carry compounds between cells. They are non-immunogenic and therefore suitable for transplantation into dystrophic muscles.

Puri is also investigating whether there are treatment conditions (including dietary supplements or other synergistic molecules) that can improve the therapeutic efficacy of HDACi. The researchers want to test if HDAC inhibitors can treat other forms of muscular dystrophy beyond DMD.

As much as Puri is focused on the future and continuing to find new and better approaches to treat muscular dystrophy, he also appreciates the importance of this vital moment and how the FDA’s decision positions the field for even more innovation.

“While muscular dystrophy was formally described by scientists 40 years ago, it has been a part of the human story since the beginning. People have been chasing something that could help, and for so long there was nothing to offer. Right now, we are paving the way for even better treatments that will be found.”

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More information on the development of HDACi as a treatment for DMD is available in the following manuscripts:

• Puri P.L., Avantaggiati M.L., Balsano C., San N., Graessmann A., Giordano A., and Levrero M.  p300 is required for MyoD-dependant cell cycle arrest and muscle specific gene transcription.  EMBO J. 16,369-383 (1997)
• Puri P.L., Sartorelli V., Yang X.J., Hamamori Y., Ogrizko , Howard B., Kedes L, Wang J.Y.J., Graessmann A., Nakatani Y., Levrero M.  Differential roles of p300 and PCAF acetyltransferases in muscle differentiation.  Mol. Cell 1, 35-45 (1997)
• Sartorelli V*., Puri P.L.* , Hamamori Y, Ogrizko V., Nakatani Y., Wang J.Y.J., Kedes L.  Acetylation of MyoD directed by PCAF is necessary for the execution of the muscle program.  Mol. Cell. 4, 725-734 (1999). *equal contribution
• Puri P.L., Iezzi, S., Stiegler P., Chen T.T., Shiltz L., Muscat G., Giordano A, Wang J.Y.J. and Sartorelli V.  Class I histone deacetylases sequentially interact with MyoD and pRb during skeletal myogenesis. Mol Cell. 8, 885-897 (2001)
• Iezzi S., Cossu G., Nervi C. Sartorelli V., and Puri P.L.  Stage-specific modulation of skeletal myogenesis by inhibitors of nuclear deacetylases Proc. Natl. Acad. Sci  99, 7757-7762 (2002)
• Iezzi S., Di Padova M., Serra C., Caretti G., Simone C., Maklan E., Zhao P., Hoffman E., Puri P.L. and Sartorelli V.  Deacetylase Inhibitors Increase Muscle cell Size by Promoting Myoblast Recruitment and Fusion Through Induction of Follistatin. Dev. Cell. 5:673-84. (2004).
• Minetti G. C., Colussi c., Adami R., Serra C.,  Mozzetta C., Parente V., Illi B., Fortuni S., Straino S., Gallinari P., Steinkhuler C., Capogrossi M., Sartorelli V., Bottinelli R., Gaetano C., Puri P.L.  Functional and morphological recovery of dystrophic muscles in mice treated with deacetylase inhibitors.  Nature Medicine 12 (10): 1147-50 (2006)
• Colussi C., Mozzetta C., Gurtner A. , Illi B., Straino S., Ragone G., Pescatori M., Zaccagnini G., Rosati G., Minetti G., Martelli F., Ricci E., Piaggio G., Gallinari P., Steinkulher C., Capogrossi M.C., Puri P.L*, Carlo Gaetano*. A Common Epigenetic Mechanism Underlies Nitric Oxide Donors and Histone Deacetylase Inhibitors Effect in Duchenne Muscular Dystrophy. Proc. Natl. Acad. Sci 105, 19183-7  (2008)  *Corresponding authors. PMCID:PMC2614736.
• Mozzetta C., Consalvi S., Saccone V., Tierney M., Diamantini A., Mitchel K.J., Marazzi G., Borsellino G., Battistini L., Sassoon D., Sacco A., Puri P.L. Fibroadipogenic progenitors mediate the ability of HDAC inhibitors to promote regeneration in dystrophic muscles of young, but not old mdx mice. EMBO Mol. Med. (2013), Apr;5(4):626-39 doi: 10.1002/emmm.201202096. [Epub ahead of print]. PMC Journal In Process.
• Consalvi S, Mozzetta C, Bettica P, Germani M, Fiorentini F, Del Bene F, Rocchetti M, Leoni F, Mascagni P, Puri P.L., Saccone V. Preclinical studies in the mdx mouse model of Duchenne Muscular Dystrophy with the Histone Deacetylase inhibitor Givinostat. Mol Med. 2013 Mar 27. doi: 10.2119/molmed.2013.00011. [Epub ahead of print]. PMCID: PMC3667212.
• Saccone V, Consalvi S, Giordani L, Mozzetta C, Barozzi I, Sandoná M, Ryan T, Rojas-Muñoz A, Madaro L, Fasanaro P, Borsellino G, De Bardi M, Frigè G, Termanini A, Sun X, Rossant J, Bruneau BG, Mercola M, Minucci S, Puri P.L. HDAC-regulated myomiRs control BAF60 variant exchange and direct the functional phenotype of fibro-adipogenic progenitors in dystrophic muscles. Genes & Development. 2014 Apr 15;28(8):841-57. doi: 10.1101/gad.234468.113. Epub 2014 Mar 28.
• Bettica P, Petrini S, D’Oria V, D’Amico A, Catteruccia M, Pane M, Sivo S, Magri F, Brajkovic S, Messina S, Vita GL, Gatti B, Moggio M, Puri P.L., Rocchetti M, De Nicolao G, Vita G, Comi GP, Bertini E, Mercuri E. Histological effects of givinostat in boys with Duchenne muscular dystrophy. Neuromuscul Disord. 2016 Jul 11. pii: S0960-8966(16)30069-4. doi: 10.1016/j.nmd.2016.07.002. [Epub ahead of print]
• Sandonà M, Consalvi S, Tucciarone L, De Bardi M, Scimeca M, Angelini DF, Buffa V, D’Amico A, Bertini ES, Cazzaniga S, Bettica P, Bouché M, Bongiovanni A, Puri P.L., Saccone V. HDAC inhibitors tune miRNAs in extracellular vesicles of dystrophic muscle-resident mesenchymal cells. EMBO Rep. 2020 Sep 3;21(9):e50863. doi: 10.15252/embr.202050863. Epub 2020 Aug 5. PMID: 32754983
• Consalvi S, Tucciarone L, Macrì E, De Bardi M, Picozza M, Salvatori I, Renzini A, Valente S, Mai A, Moresi V, Puri P.L.. Determinants of epigenetic resistance to HDAC inhibitors in dystrophic fibro-adipogenic progenitors. EMBO Rep. 2022 Jun 7;23(6):e54721. doi: 10.15252/embr.202254721. Epub 2022 Apr 4. PMID: 35383427
• Mozzetta C, Sartorelli V, Steinkuhler C, Puri P.L.. HDAC inhibitors as pharmacological treatment for Duchenne muscular dystrophy: a discovery journey from bench to patients. Trends Mol Med. 2024 Mar;30(3):278-294. doi: 10.1016/j.molmed.2024.01.007. Epub 2024 Feb 26. PMID: 38408879.

Sanford Burnham Prebys physician-scientist advises the FDA on cell-based therapeutics, tissue engineering and gene therapies.

Sanford Burnham Prebys physician-scientist Evan Y. Snyder, MD, PhD, was reappointed to the Cellular, Tissue, and Gene Therapies Advisory Committee (CTGTAC) in the Center for Biologics Evaluation and Research (CBER) at the Food and Drug Administration (FDA). He is serving a four-year term from August 30, 2024, to March 31, 2028.

We sat down with Snyder to learn more about the committee, his advisory role and the importance of safeguards for new therapies.

What are FDA advisory committees?

The FDA advisory committees advise the FDA commissioner in many areas to support the agency’s mission of protecting and promoting public health. This includes advising on whether or not new treatments or other products under the agency’s purview should be approved to enter the marketplace.

There are many committees that focus on topics ranging from food and tobacco products to digital health and veterinary medicine. My committee oversees cell-based therapeutics, tissue engineering and gene therapies.

Who serves on these committees?

Typically, committees have between 12-16 members. Most are academics with complementary sets of expertise. My committee includes individuals proficient in stem cell biology, gene therapy, biomedical engineering, surgery, biostatistics and clinical trial design, among others.

Other members often include a non-voting ex officio industry representative and a voting patient advocate representative. And, for each meeting, you can “roll-in” ad hoc people that have a particular expertise on the topic that’s being discussed.

What is your history on the Cellular, Tissue, and Gene Therapies Advisory Committee?

In the early days of the stem cell field, I was a founding member of the FDA and National Institutes of Health (NIH) Stem Cell Working Group to generate guidelines for human transplantation, and then served on the FDA’s Biological Response Modifiers Advisory Committee which derived from that Working Group, and which ultimately gave rise to the CTGTAC. I served as a recurring ad hoc member of CTGTAC for about eight years. In 2011, I was made acting chair of the committee. And then in 2012, I was appointed as permanent chair.

After my two-year term was complete, I was asked to stay on for a second two-year term. At that point, I hit my term limits and went into my “latency” period. Last year, I was asked to give the committee a lecture on what to look for in reviewing cell-based therapies and cell-based therapy clinical trials. I guess they found my advice useful because I received an invitation to return to the committee.

Can you share a case where you learned a valuable lesson about regulation?

One sobering lesson was learned at my very first session. I was so excited about being on this committee, recognizing that we were the “gatekeepers” of health care for the country and had the  power to do such impactful things.

I received the materials to review for my first case — hundreds of pages. They were from a company that wanted to take skin biopsies obtained from the back of a patient’s ear, dissociate the sample into single skin cells and expand them in cell culture, and then send the cells back to a plastic surgeon who would inject them into the nasolabial fold of the donor patient to efface the aging-related furrows there and make the face look younger and pumper.

I confess that I was really having trouble getting invested in the case as I was expecting something more meaningful for us to adjudicate. And then, at lunch, one of the more senior committee members off-handedly remarked how important this case was. Because I could not tell if he was being sarcastic or earnest, I asked him (a bit sheepishly) to elaborate.

He responded that, while the matter may sound trivial, if our committee approved this “therapy”, it would represent only the second autologous cell-based therapy ever approved by the FDA. He added that, if we approve this one, practitioners could start using autologous cells (especially derived from skin) off-label for all kinds of indications whether we had investigated and sanctioned those uses or not.

That changed my perspective immediately. After deliberating, we denied the company approval based on a failure to prove adequate safety. For example, they hadn’t met the required bar for showing that the injected skin cells didn’t continue to proliferate inappropriately under certain common conditions. Also, the company had not followed the patients longitudinally enough to know the long-term outcome. They had not adequately characterized the cells they had expanded artificially in a tissue culture dish and were now transplanting.

How does the committee vote? 

We take two votes. First, we vote on whether the applicants have surpassed a threshold for safety. Then we take a second vote on whether they have met their burden for showing efficacy beyond standard-of-care.

When you vote, it’s like “American Idol.” You have a little switch in front of you, and you flip it to vote “yes” (green), “no” (red) or “abstain” (yellow). Your vote then goes up on a tally screen that all (including the public) can see.

At the end of each vote, each committee member has to explain the rationale for why he/she voted that way.

What is the most visible case you have reviewed?

We were asked to review a case related to what is commonly called “human cloning.” The scientific term is somatic cell nuclear transfer (SCNT). One takes a skin cell from a patient, removes the nucleus transfers it to an unfertilized egg (oocyte) whose own nucleus has been removed. Then you “zap” the egg with the donated nucleus, and the egg acts as if it has been fertilized. It begins to divide into 2 cells, then 4 cells, then 6 cells, and form a blastula, and ultimately — if allowed to go to beyond 14 days (which is typically not sanctioned in this country) — into an embryo that will be just like whoever donated that skin cell nucleus. These experiments are exceedingly controversial and actually allowing a human embryo to go to term is outlawed here and in most countries, although SCNT is used routinely for agricultural animals.

There is one indication, however, where SCNT could be therapeutically beneficial in humans. That is in the case of rare mitochondrial diseases which tend to be lethal or incapacitating. Mitochondria are the powerhouses of the cell; when they are diseased, the kids are born with heart, muscle, brain, eye, and/or liver disease — these are tissues that demand high energy.

The mitochondria and the genes encoding mitochondria come only from the mom, not from both parents. A skilled and esteemed reproductive biologist came to the committee with a proposal to perform SCNT for parents at high risk for having kids with mitochondrial disease. The skin cell nucleus from a mom carrying abnormal mitochondria would be placed in the unnucleated egg of a normal woman, which would then be fertilized by the dad in vitro. This was, of course, very contentious. Some members of the press said the procedure would create “three parent” babies and create monsters. There were protests.

Ultimately, our committee had to decide whether to approve a clinical trial or not. And that would help determine whether the U.S. would begin to embrace SCNT. We concluded that the disease represented a critical unmet medical need, requiring new interventions. We determined that the proposed strategy was a reasonable, albeit an arduous, approach if a couple wanted a baby with the genetic inheritance of both parents yet without abnormal mitochondria. However, in our view, the bar for safety had not yet been met (based on the preclinical animal studies). We provided a laundry list of studies that should be pursued before coming back to the committee.

The United Kingdom was considering the same issue. While the UK was holding hearings on the topic, I was summoned (as the committee’s chairman and, hence, the United States representative) to testify before the parliamentary committee, explaining our rationale for not approving a clinical trial for SCNT to treat mitochondrial disease.

Why is it important to you to serve on this committee?

As a physician, I make an impact on each kid I take care of, kid by kid. But there’s a limited number of kids that I can treat during my career. As a scientist, if I get it right, I can make an impact on thousands of patients, but that might not even occur in my lifetime.

On this committee, I can make an impact on potentially thousands of patients in the near term. That comes with a requirement for being incredibly rigorous in assessing the data we are presented with, as well as appreciating the practicalities of what it takes to actually do medicine and improve the lives of real patients in the real world — sometimes needing to make a decision in the face of incomplete and imperfect data. Forestalling a decision can be a decision in itself.

I think as an educator, as a physician, and as a scientist, I have a unique set of skills that might make an impact here.

Glycobiology is the study of the structure, biosynthesis and biology of glycans — carbohydrates or sugars that cover the surfaces of all cells and many proteins.

In recent years, understanding and recognition of the importance of glycans has grown dramatically.

They are, among other things, critical to the maintenance of cell and tissue structure and integrity. Their dysfunction is linked to a growing list of human diseases. They have played surprising roles in human evolution.

Beginning in 1999, a cohort of researchers working in emerging field of glycobiology created the first textbook on the subject: “Essentials of Glycobiology.”  The fourth edition was published in 2022.

The Society for Glycobiology recently honored the editors for their ongoing work with its 2024 Distinguished Service Award. Among the honorees, Hudson Freeze, PhD, director of the Sanford Children’s Health Research Center at Sanford Burnham Prebys and a renowned expert in congenital disorders of glycosylation, a group of rare metabolic disorders that primarily afflict children.