Category: Blogs

On December 19th, the European Medicines Agency’s (EMA’s) Committee for Medicinal Products for Human Use (CHMP) recommended the stem cell product Holoclar (Chiesi Farmaceutici S.p.A.)  as a first-ever medicinal treatment for severe limbal stem cell deficiency, a condition caused by physical or chemical burns to the eye or eyes in adults, which can result in blindness.

The EMA has designated Holoclar as both an orphan medicine and an advanced therapy medicinal product, which enabled the manufacturer to receive free scientific advice and protocol assistance for drug development. The CHMP recommendation was based on an assessment by the expert Committee for Advanced Therapies. Such steps are taken to promote the development of medicines for rare diseases and to encourage innovative medicinal products, according to the EMA statement.

Holoclar is produced by Chiesi under an agreement with Holostem Terapie Avanzate, an Italian biotechnological company devoted to the development, manufacture, registration and distribution of Advanced Therapy products based on cultures of epithelial stem cells both for cell therapy and gene therapy. Holoclar was designed specifically for the treatment of severe limbal stem cell deficiency (LSCD).

The transparency of the cornea is essential to ensure the ability to see properly. Corneal cell renewal and repair are dependent upon the cells present in the limbus, which is found in a small area of the eye between the cornea and the conjunctiva.

Thermal or chemical burns to the eye can destroy the corneal surface (epithelium) and the limbus, causing a deficiency of limbal cells. If this happens, the cornea is covered by a different epithelium following an invasion of cells from the conjunctiva. This process leads to neovascularization, chronic inflammation and stromal scarring, rendering the cornea opaque and results in subsequent loss of vision. Conventional corneal transplants are an ineffective treatment in such cases.

The therapy is based on cultures of limbal cells taken from the patient, which, once they have successfully grafted, regenerate the corneal epithelium and restore its functions. Limbal cell cultures even allow the possibility of treating patients with a loss of corneal epithelium in both eyes, provided that a small portion of limbus remains in one of the eyes.

Holoclar, is an autologous culture of limbal stem cells. It is made from a biopsy taken from a small undamaged area (minimum of 1-2 mm2) of the patient’s cornea and grown in the laboratory using cell culture, and transplanted in the affected eye or eyes after removal of the damaged area. Such cultures engraft and permanently regenerate a functional corneal epithelium allowing recovery of visual acuity. replacing damaged limbal stem cells.

Holoclar can offer an alternative to corneal transplantation for replacing altered corneal epithelium in some cases, and it has been shown to increase the chances of a successful corneal transplant where the injury has caused extensive eye damage. It reduces the risk of rejection compared with transplanting tissue from a donor and does not require surgery on the patient’s other eye as only a small biopsy is performed to collect the cells, thus reducing the risk of damage to the healthy eye. Therefore, Holoclar may also be suitable where both eyes are affected by moderate to severe LSCD.

Limbal stem cell deficiency is estimated to affect about 3.3 per 100,000 people in the EU, causing pain, photophobia, inflammation, corneal neovascularization, loss of corneal transparency, and eventually blindness.

The recommendation was made by the Committee for Medicinal Products for Human Use (CHMP) based on a robust assessment carried out by the Committee for Advanced Therapies (CAT), the Agency’s expert committee for ATMPs.

“This recommendation represents a major step forward in delivering new and innovative medicines to patients,” says Enrica Alteri, Head of EMA’s Human Medicines Evaluation Division. “EMA has used all available support tools to facilitate the development and assessment of Holoclar. It is an advanced therapy medicinal product that has been designated as an orphan medicine. This allowed the Agency to provide support including several rounds of free scientific advice to the applicant during Holoclar’s development.”

The Committee for Advanced Therapies and the CHMP panels determined that although the product’s benefits outweigh its risks, the marketing authorization should be conditional because the data thus far are retrospective and not yet comprehensive. Therefore, the EMA says, “an additional study on the use of Holoclar should be conducted.”

The opinion adopted by the CHMP at its December 2014 meeting is an intermediary step on Holoclar’s path to patient access. The CHMP opinion will now be sent to the European Commission for the adoption of a decision on an EU-wide marketing authorization. After that, decisions about price and reimbursement will take place at the level of each member state,  taking into account the potential role/use of this medicine in the context of the national health system of that country.

1. First stem-cell therapy recommended for approval in EU, European Medicines Agency Press Release, December 19, 2014

2. First-Ever Stem Cell Therapy Recommended in EU, Miriam E. Tucker, Medscape, December 19, 2014

3. Chiesi website

4. Holostem website

Having treated 36 patients in two clinical trials for Stargardt’s Macular Dystrophy (SMD – 24 patients to date) and for dry Age-Related Macular Degeneration (AMD – 12 patients to date), Advanced Cell Technology reported the interim results obtained with 18 of these patients (9 in each trial) in the US-based studies. Both trials (NCT01345006 – Stargardt’s, and NCT01344993 – AMD) began in July 2011, giving the company up to three-year’s data for the earliest patients, and a median of 22 months followup for all. The interim results were reported in The Lancet, published online October 14, 2014 in: “Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt’s macular dystrophy: follow-up of two open-label phase 1/2 studies”.

An additional Stargardt’s trial, being conducted at two clinics in the United Kingdom, with 12 patients enrolled (NCT01469832), along with 3 of the 4 patients treated in each of two trials with better vision candidates, as part of the two clinical trials in the publication (Phase IIa), were not included in The Lancet results.

As noted by Paul K. Wotton, Ph.D., President and Chief Executive Officer of Advanced Cell Technology, “These study results represent an important milestone and strengthen our leadership position in regenerative ophthalmology. We would like to thank the patients for their willingness to participate in these studies. Our findings underscore the potential to repair or replace tissues damaged from diseases. We plan to initiate comprehensive Phase 2 clinical trials for the treatment of both AMD and SMD, two disease states where there is currently no effective treatment.”

Robert Lanza, M.D., Chief Scientific Officer of ACT and co-senior author of the paper, commented, “Diseases affecting the eye are attractive first-in-man applications for this type of investigational therapy due to the immune-privileged nature of the eye. Despite the degenerative nature of these diseases, the vision of 10 of 18 patients showed measurable improvement at the six month follow up, after transplantation of the RPE cells. Furthermore, the cells have been well tolerated for a median period of 22 months with two of the patients treated more than three years ago. We are pleased that there have been no serious safety issues attributable to the cells observed in any of the patients.”

Steven Schwartz, M.D., Ahmanson Professor of Ophthalmology at the David Geffen School of Medicine at UCLA and retina division chief at UCLA’s Jules Stein Eye Institute, principal investigator and co-lead author of the publication said, “The data published in The Lancet support the potential safety and biological activity of stem cell-derived retinal tissue. Once again, surgical access to the subretinal space has proven safe. However, for the first time in humans, terminally differentiated stem cell progeny seem to survive, and do so without safety signals. Combined with the functional signals observed, these data suggest that this regenerative strategy should move forward. This is a hopeful and exciting time for ophthalmology and regenerative medicine.”

These two studies provide the first evidence of the mid- to long-term safety, survival, and potential biologic activity of pluripotent stem cell progeny into humans with any disease. In addition to showing no adverse safety issues related to the transplanted tissue, anatomic evidence confirmed successful engraftment of the RPE cells, which included increased pigmentation at the level of the RPE layer after transplantation in 13 of 18 patients.

There was no evidence of adverse proliferation, rejection, or serious ocular or systemic safety issues related to the transplanted tissue. Adverse events were associated with vitreoretinal surgery and immunosuppression. Thirteen (72%) of 18 patients had patches of increasing subretinal pigmentation consistent with transplanted retinal pigment epithelium. Best-corrected visual acuity, monitored as part of the safety protocol, improved in ten eyes, improved or remained the same in seven eyes, and decreased by more than ten letters in one eye, whereas the untreated fellow eyes did not show similar improvements in visual acuity. Vision-related quality-of-life measures increased for general and peripheral vision, and near and distance activities, improving by 16–25 points 3–12 months after transplantation in patients with atrophic age-related macular degeneration and 8–20 points in patients with Stargardt’s macular dystrophy.

The SMD and dry AMD trials are prospective, open-label studies designed to evaluate the safety and tolerability of human embryonic stem cell (hESC)-derived RPE cells following sub-retinal transplantation into patients at 12 months, the studies’ primary endpoint. Three dose cohorts were treated for each condition in an ascending dosage format (50,000 cells, 100,000 cells, and 150,000 cells). Both the SMD and dry AMD patients had subretinal transplantation of fully-differentiated RPE cells derived from hESCs.

Dr. Anthony Atala, a surgeon and director of the Wake Forest Institute for Regenerative Medicine at Wake Forest University in an accompanying commentary in The Lancet said:

The co-authors of the study summarized their interpretation of their results in this way:

References:

1. ACT Announces Positive Results from Two Clinical Trials Published in The Lancet Using Differentiated Stem Cell-Derived Retinal Pigment Epithelium (RPE) Cells for the Treatment of Macular Degeneration, ACT Press Release, October 14, 2014

2. Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt’s macular dystrophy: follow-up of two open-label phase 1/2 studies, Schwartz, SD, Lanza R, et al, The Lancet, Online, October 14, 2014.

Encouraging New Paper on ACT Stem Cell-Based Trial for Macular Degeneration, Paul Knoepfler, Knoepfler Lab Stem Cell Blog, October 14, 2014

Embryonic Stem Cells Restore Vision In Preliminary Human Test, Rob Stein, NPR Health Blog, October 14, 2014

After several attempts to gain approval for its NDA for Ilunien, the FDA has finally seen the light (after approval in the UK, Germany, and marketing or pending approvals in seventeen other EU countries).

I first began writing about Iluvien in July 2010 – see my comprehensive writeup about the technology behind this and other sustained delivery drug systems – Iluvien and the Future of Ophthalmic Drug Delivery Systems. In addition I have written about the products progress in seven updates, the latest in August 2012, Iluvien Update 7: Alimera Sciences to Re-File for FDA Approval of Iluvien for Chronic DME

Here are the statements from the two companies involved in bringing Iluvien to the market, Alimera Sciences, the marketing arm, and pSivida the licensor of the technology to Alimera:

Alimera Sciences announced today that the U.S. Food and Drug Administration (FDA) has approved ILUVIEN for the treatment of diabetic macular edema (DME) in patients who have been previously treated with a course of corticosteroids and did not have a clinically significant rise in intraocular pressure (IOP). Alimera currently intends to begin selling ILUVIEN in the U.S. in the first quarter of 2015.

“We are very excited by this news late today and by the broader label ILUVIEN has been granted by the FDA,” said Dan Myers, president and chief executive officer of Alimera. “We plan to issue a more detailed announcement on Monday morning.”

And, from pSivida:

pSivida today announced that the U.S. Food and Drug Administration (FDA) has approved ILUVIENr for the treatment of diabetic macular edema (DME). It is indicated for patients who have been previously treated with a course of corticosteroids and did not have a clinically significant rise in intraocular pressure (IOP). A single injection of the ILUVIEN micro-insert provides sustained treatment of DME for 36 months. Approximately 560,000 people in the U.S. are estimated to have clinically significant DME, the most frequent cause of vision loss in individuals with diabetes and the leading cause of blindness in young and middle-aged adults in developed countries. ILUVIEN is expected to be commercially available in the U.S. in early 2015.

FDA approval of ILUVIEN entitles pSivida to a $25 million milestone from its licensee Alimera Sciences. pSivida will also be entitled to 20% of the net profits from sales of ILUVIEN in the U.S.

“FDA approval of ILUVIEN, our third FDA-approved product for retinal disease, provides an important treatment option for DME patients in the U.S., the majority of whose DME, despite anti-VEGF intra-ocular injections as frequently as monthly, is not optimally managed. ILUVIEN’s clinical trials showed that ILUVIEN can actually reverse vision loss in many DME patients. Another advantage of ILUVIEN over existing therapies is that a single injection provides sustained therapy for three years,” said Paul Ashton, Ph.D., president and chief executive officer of pSivida.

“The $25 million milestone will help finance our ongoing product development program, including MedidurT for posterior uveitis and TethadurT for the sustained delivery of biologics,” added Dr. Ashton. pSivida is independently developing Medidur, an injectable, sustained release micro-insert of the same design and delivering the same drug as ILUVIEN, for the treatment of chronic posterior uveitis, the third largest cause of blindness in the U.S. The Company plans to seek FDA approval of this product on the basis of its ongoing single Phase III clinical trial. Enrollment of this study is expected to be completed by the end of the first quarter of calendar 2015.

ILUVIEN is already commercially available in the U.K. and Germany, and has received or is pending marketing approval in seventeen other EU countries, for the treatment of patients with the chronic DME insufficiently responsive to available therapies. “We are very pleased that the FDA’s approval of ILUVIEN is not limited, as in the EU, to the subset of patients with chronic DME, patients who have failed other therapies, or patients who have had cataract surgery,” continued Dr. Ashton.

ILUVIEN is an injectable micro-insert that provides sustained treatment through continuous delivery of a submicrogram dose of the corticosteroid fluocinolone acetonide for 36 months. Current standard-of-care therapy requires anti-VEGF injections into the eye as frequently as monthly, and studies show that over 50 percent of patients are not optimally managed with this treatment. FDA approval was based on clinical trial data that showed that at month 24, 28.7 percent of patients receiving ILUVIEN experienced an improvement from baseline in their best corrected visual acuity on the Early Treatment Diabetic Retinopathy Study (ETDRS) eye chart of 15 letters or more. This improvement in vision was maintained through 36 months, the end of the trials. 

By Ben Shaberman,  September 8, 2014

Your eyes are not just windows to your soul, but to your health as well. People rarely pay attention to their eyes, until something goes wrong. The eye is a delicate organ, and vision is a complex process involving various components.

Photoreceptors, in particular, get a lot of attention from researchers because they’re the main cells in the retina that make vision possible. They convert light into electrical signals, which are sent to the brain and used to construct the images we see. Also, many retinal diseases begin with loss of photoreceptors.

However, the retina is like a multi-layer cake, with each layer comprised of different types of cells, all playing important roles in retinal health and vision. While preserving and restoring photoreceptors is often job number one for scientists, they also explore ways to protect other retinal cells from deterioration and even harness them to restore vision.

Here’s a summary of the major retinal cell types, their functions and their potential roles in future treatments of diseases:

Choroid – The choroid is a layer of blood vessels that supplies oxygen and nourishment to the retina. Defects in the CHM gene cause choroideremia, a disease characterized by deterioration of the choroid, retinal pigment epithelium (RPE) and photoreceptors. In the wet form of age-related macular degeneration, leaky blood vessels expand from the choroid into the retina – a process called choroidal neovascularization – which causes loss of photoreceptors and central vision.

Retinal pigment epithelium – Also known as the RPE, this is a single layer of cells above the photoreceptors that provides them with essential nutrition and waste removal. In age-related macular degeneration (AMD) and Stargardt disease (SMD), toxic waste products accumulate in the RPE or between the RPE and photoreceptors. Subsequently, the RPE deteriorates, leading to loss of photoreceptors.

Photoreceptors -These are the retinal cells, known as rods and cones, that initiate the vision process by converting light into electrical signals. Rods provide low-light and peripheral vision. Cones are concentrated in the macula, the central region of the retina, and provide central and color vision. The outer segments of rods and cones are antenna-like projections that absorb light and convert it into electrical signals. Inner segments are the cell bodies where other supportive functions are performed. The adult human retina has approximately 125 million photoreceptors.

Bipolar cells – Their job is to receive electrical information on lighting intensity from photoreceptors and pass it along to other retinal cells. Bipolar cells often survive after photoreceptors are lost to disease. This makes them an attractive target for emerging optogenetic treatments, which are designed to provide light sensitivity and restore vision.

Ganglion cells – Ganglion cells receive input from many different cells in the inner retinal layers and process visual information, including detection of edges, contrast and colors. Ganglion cells extend to form an optic nerve, a million-fiber cable that conveys visual information from the eye to the brain. In people with advanced retinal disease, ganglion cells often survive longer than bipolar cells, making them a potential target for optogenetic therapies. Currently, scientists believe that bipolar cells may provide a more detailed visual experience than ganglion cells when treated with a light-sensing therapy, because they reside in layers of the retina closer to photoreceptors.

Muller glia – Muller cells extend through the retina, like spokes of a wheel, providing structural support and guiding light through the inner retina. They also transport molecules critical to retinal health and vision. Researchers believe Muller cells may even have the capacity to become new photoreceptors, which could lead to restoring vision. The research is still new, but success might someday have a big impact on the vision of people with advanced diseases.

The processing of visual information in the retina-beginning with 125 million photoreceptors and converging on a one-million-fiber optic nerve-remains a subject of intense research. There’s still much that scientists don’t know about the retinal cells and their roles. For example, little is known about the processing activities of amacrine and horizontal cells, which reside between bipolar and ganglion cells. However, advancing imaging technologies, including adaptive optics and optical coherence tomography, are helping complete the picture.

For additional information about retinal anatomy and function, please see the Eye on the Cure post “Appreciating the Beauty of the Retina.” The University of Utah’s Webvision is one of the best online sources for detailed information about the retina. I also want to thank John Flannery, Ph.D., at the University of California, Berkeley, for his editorial input.

Earlier this week, it was reported that Masayo Takahashi, an ophthalmologist at the RIKEN Center for Developmental Biology (CDB) in Kobe had appeared in front of a 19-member health-ministry committee for the safety of the clinical use of stem cells. She was flanked by Shinya Yamanaka, the biologist who first created iPS cells. Yamanaka shared the 2012 Nobel Prize in Physiology or Medicine for his breakthrough and now heads the Center for iPS Cell Research and Application in Kyoto. Takahashi was seeking approval to implant a retinal pigmented epithelial (RPE) sheet made from induced pluripotent stem (iPS) cells into a human patient.

Takahashi and her collaborators had shown in monkey and mice studies that iPS cells generated from the recipients’ own cells did not provoke an immune reaction that causes them to be rejected. There had been concerns that iPS cells could cause tumours, but Takahashi’s team found that to be unlikely in mice and monkeys.

To counter further fears that the process of producing iPS cells could cause dangerous mutations, Takahashi’s team had performed additional tests of genetic stability. Guidelines covering the clinical use of stem cells require researchers to report safety testing on the cells before conducting transplants. The health ministry said that no problems were found and that the human trial could commence.

Only four days later (Friday, September 12th), the first patient was treated with the implanted sheet of RPE cells. She derived them from the patient’s skin cells, after producing induced pluripotent stem (iPS) cells and then getting them to differentiate into retinal cells.

This is a major first for the stem cell and regenerative medicine fields.

Takahashi and her collaborators have been using induced pluripotent stem (iPS) cells to prepare a treatment for age-related macular degeneration. Unlike RPE derived from embryonic stem cells (i.e., as being done by Advanced Cell Technology), iPS cells are produced from adult cells, so they can be genetically tailored to each recipient. They are capable of becoming any cell type in the body, and have the potential to treat a wide range of diseases. The CDB trial will be the first opportunity for the technology to prove its clinical value.

A Japanese woman in her 70s is the world’s first recipient of cells derived from induced pluripotent stem cells, a technology that has created great expectations since it could offer the same advantages as embryo-derived cells but without some of the controversial aspects and safety concerns.

In a two-hour procedure starting at 14:20 local time, a team of three eye specialists lead by Yasuo Kurimoto of the Kobe City Medical Center General Hospital, transplanted a 1.3 by 3.0 millimeter sheet of retinal pigment epithelium cells into an eye of the Hyogo prefecture resident, who suffers from age-related macular degeneration.

The procedure took place at the Institute of Biomedical Research and Innovation Hospital, next to the RIKEN Center for Developmental Biology (CDB) where ophthalmologist Masayo Takahashi had developed and tested the epithelium sheets.

Afterwards, the patient experienced no effusive bleeding or other serious problems, as reported by RIKEN.

Another important element to this story is that Japan has a clinical translation pipeline that is now faster with recent changes in regulations than that of the US. For example, this and future iPS cell-based transplants were approved as part of a clinical study, a type of clinical research mechanism that doesn’t exist in the US. It is safe to say that the same technology with the same research team and outstanding level of funding would still be at least a few years away from their first patient in the US due to the different regulatory scheme.

As noted by Dr. Paul Knoepfler, in his writeup about the procedure:

 “The patient is clearly a brave hero. The team transplanted a huge (from a bioengineering perspective) 1.3 x 3.0 mm sheet of RPEs into the retina of the patient, who did not have any clear immediate side effects from the procedure. Keep in mind again that this sheet was made indirectly from the patients own skin cells so it is an autologous (or self) transplant, a notion that 10 years ago would have seemed entirely like sci-fi.”

“This is not only a huge milestone, but also an astonishingly fast translation of iPS cell technology from the bench to the bedside.”

 “Also, on the positive side we have the encouraging results from the ongoing clinical trials from Advanced Cell Technology (ACT) using a similar approach to macular degeneration, but employing human embryonic stem cells to make the RPEs.”

“For the vision impaired and the broader stem cell field, it is heartening to have two such capable teams working to cure blindness with pluripotent stem cells.”

1.Next-generation stem cells cleared for human trial: Japanese team will use ‘iPS’ cells to treat patient with degenerative eye disease, Nature, David Cyranoski, September 10, 2014.

2. Japanese woman is first recipient of next-generation stem cells: Surgeons implanted retinal tissue created after reverting the patient’s own cells to ‘pluripotent’ state, Nature, David Cyranoski, September 12, 2014.

3. Stem cell landmark: patient receives first ever iPS cell-based transplant, Knoepfler Lab Stem Cell Blog, Paul Knoepfler, Septermber 12, 2014.

There is breaking news this week about Avalanche Biotechnologies and I would like to share it, as well as a brief update on the clinical trial underway using their proprietary gene therapy approach to treating the wet form of AMD.

Now for the breaking news. On May 5th, in a joint announcement, Avalanche and Regeneron Pharmaceuticals said that they were undertaking a broad collaboration “to discover, develop and commercialize novel gene therapy products for the treatment of ophthalmic diseases. The collaboration covers novel gene therapy vectors and proprietary molecules, discovered jointly by Avalanche and Regeneron, and developed using the Avalanche Ocular BioFactoryTM, an adeno-associated virus (AAV)-based, proprietary, next-generation platform for the discovery and development and delivery of gene therapy vectors for ophthalmology.”

Under the terms of the agreement, Avalanche will receive an upfront cash payment, contingent payments of up to $640 million upon achievement of certain development and regulatory milestones, plus a royalty on worldwide net sales of collaboration products. The collaboration covers up to eight distinct therapeutic targets, and Regeneron will have exclusive worldwide rights for each product it moves forward in clinical development. In addition, Avalanche has the option to share in development costs and profits for products directed toward two collaboration therapeutic targets selected by Avalanche.

As part of the agreement, Regeneron has a time-limited right of first negotiation for certain rights to AVA-101, Avalanche’s gene therapy product targeting vascular endothelial growth factor (VEGF) currently under development for the treatment of wet age-related macular degeneration (AMD), upon completion of the ongoing Phase 2a trial.

“We look forward to the opportunity to collaborate with Avalanche, a leader in the field of next-generation gene therapy technologies,” said George D. Yancopoulos, M.D., Ph.D., Chief Scientific Officer of Regeneron and President of Regeneron Laboratories. “This collaboration highlights the commitment by Regeneron to invest in potentially breakthrough therapies that could benefit patients with sight-threatening diseases.”

“We are excited to work with Regeneron to discover and develop novel gene therapy medicines for serious eye diseases,” said Thomas W. Chalberg, Ph.D., co-founder and Chief Executive Officer of Avalanche Biotechnologies. “The collaboration will bring together Avalanche’s novel platform technology with Regeneron’s proprietary molecules and research capabilities, with the goal of creating a new class of next-generation biologics in ophthalmology. Regeneron is a terrific partner for their scientific leadership, as well as their product development capabilities and commercialization track-record.”

For those of you not familiar with Regeneron Pharmaceuticals, they are a leading science-based biopharmaceutical company based in Tarrytown, New York that discovers, invents, develops, manufactures, and commercializes medicines for the treatment of serious medical conditions. Regeneron commercializes medicines for eye diseases, colorectal cancer, and a rare inflammatory condition, and has product candidates in development in other areas of high unmet medical need, including hypercholesterolemia, oncology, rheumatoid arthritis, asthma, and atopic dermatitis.

In the eye disease field, their major product is Eylea, an anti-vascular endothelial growth factor (VEGF) agent that is intravitrealy injected for the treatment of  wet AMD, in competition with Roche/Genentech’s Avastin, and Lucentis.

The problem with the use of the current anti-VEGF drugs is the need for up to eight to twelve injections yearly, to maintain the gains in visual acuity and/or prevent the re-occurrence of the underlying neovascular degeneration. The reason for the collaboration with Avalanche is that its BioFactoryTM is expected to deliver a therapeutic protein to combat wet AMD for at least 18 months and, potentially for several years, from a single injection. (For more about this technology, again, please see my initial writeup.)

And that leads to the recent clinical trial update provided by founder and CEO, Thomas Chalberg at the the Angeogenisis, Exudation and Degeneration 2014 Conference, held in Miami, FL on February 8, 2014:

Retina Today, April 2014

One hundred microliters of AVA-101 (Ocular BioFactoryTM, Avalanche Biotechnologies) was injected subretinally in patients. Anti-VEGF protein levels ramp-up over 6 to 8 weeks, during which 2 injections of ranibizumab (Lucentis) were given. After 8 weeks, ranibizumab was only given to the treatment group on a prn basis as rescue therapy.

Patients were tracked for 12 months after injection and came in for monthly visits. The control group, which did not receive an injection of AVA-101, required a mean 3 injections of ranibizumab during the 12-month period. The treatment group required a mean 0.3 ranibizumab injections over the same period.

Patients received ranibizumab injections if fluid appeared on OCT or fluorescein angiography, or if there was vision loss attributable to increased area of choroidal neovascularization.

Patients in the study had experience with anti-VEGF treatment, averaging 18 intravitreal anti-VEGF treatments prior to study enrollment.

“Because these patients are coming heavily pre-treated, we didn’t necessarily expect them to gain additional vision,” Dr. Chalberg said. “But treated patients actually gained between 9 and 12 letters over 12 months.”

Dr. Chalberg reported no drug-related adverse events, retinal tears, or retinal detachments. Procedure-related adverse events were minor and self-resolving.

“Ocular gene therapy might be a long-term viable option for patients with wet AMD,” Dr. Chalberg said.

AVA-101 is a strand of therapeutic DNA packaged inside an adeno-associated virus (AAV), which, when injected subretinally, up-regulates the body’s production of anti-VEGF. Subretinal injection appeared to be safe and was well tolerated, Dr. Chalberg reported, and allowed AVA-101 injections to better stimulate anti-VEGF production than if delivered intravitrealy.

Dr. Chalberg reported that an on-going phase 2A study currently has 40 patients enrolled.

1. Chalberg TW. Anti-VEGF gene therapy: early clinical results using the Ocular BioFactoryTM in wet AMD. Paper presented at: Angiogenesis, Exudation, and Degeneration 2014; February 8, 2014; Miami, FL.

In order to learn about jCyte, I contacted Dr. Henry Klassen, it’s founder and Associate Professor of the Gavin Herbert Eye Institute and its Stem Cell Research Center at the University of California, Irvine (UCI), and learned about his new company and about how its program to restore vision to those with RP will evolve.

In doing additional background research, I quickly discovered that ReNeuron, a UK biotechnology company, was also working towards that same goal and, in fact, was working with Dr. Michael Young of Schepens Eye Research Instititute who, it turned out, was a past co-author with Dr. Klassen’s in working on pre-clinical animal studies in this field.

In this writeup, I intend to tell you what retinal progenitor cells are, what they can do, and why this might be an important technique for restoring vision in those with damaged or destroyed photoreceptors.

I will also tell you about the companies involved, where the state of development stands and provide a possible timetable to the future, including the pre-clinical work underway and the road to human clinical trials.

I have also included some information about competitive activities, and where these alternative techniques/technologies for restoring vision for those with damaged photoreceptors stand.

There is a group of  retinal degenerative diseases that constitute a significant source of visual disability in both the developed and undeveloped world, and where current therapeutic options are quite limited.

For instance, the loss of photoreceptor cells, as seen in the later stages of retinitis pigmentosa (RP), geographic atrophy (GA) in dry AMD, and the late stages of Stargardt’s disease (SMD), results in permanent visual loss for which no restorative treatment is as yet available. But, the notion that photoreceptor cells might be replaceable in therapeutic settings has been given recent support by experimental work in animal models [1].

A progenitor cell is a biological cell that, like a stem cell, has a tendency to differentiate into a specific type of cell, but is already more specific than a stem cell and, can be pushed to differentiate into its “target” cell. The most important difference between stem cells and progenitor cells is that stem cells can replicate indefinitely whereas progenitor cells can divide only a limited number of times.

Most progenitors are described as multipotent, not pluripotent. In this point of view, they may be compared to adult stem cells, but progenitors are said to be in a further stage of cell differentiation. They are in the “center” between stem cells and fully differentiated cells. The kind of potency they have depends on the type of their “parent” stem cell and also on their niche, in this case, eye-derived progenitor cells that have partially differentiated into retinal cells.

Retinal progenitor cells are self-renewing cells capable of differentiating into the different retinal cell types including photoreceptors (rod and cone cells), even neuron cells, and they have shown promise as a source of replacement cells in experimental models of retinal degeneration.

ACT’s primary research program uses retinal pigment epithelium (RPE) cells derived from embryonic stem cells in the treatment of dry AMD, Stargardt’s disease, and soon myopic macular degeneration (MMD). The company is currently injecting these hESC-derived RPE cells subretinally into humans in three clinical trials, in which more than 30 patients have been treated to date, with no reported problems of safety and, in most cases, with reported improved vision. In one case, a dry AMD patient reportedly went from 20/400 vision, to 20/40 vision within several weeks of treatment. [2]. We believe that in this case, his dormant (but still alive) photoreceptors were re-activated by the RPE cell treatment.

The MMD clinical trial has received IND approved and is expected to begin shortly.

The company is also undertaking early pre-clinical animal studies in their laboratories with several types of  progenitor cells.

As reported by Dr. Robert Lanza, the company’s CSO at the last shareholder’s meeting in October 2013 [3]:

 “We have, as I mentioned earlier, a number of other cell types that we are studying in the eye field, including our retinal neural progenitors, photoreceptor progenitors, and also ganglion progenitors. As regard to the retinal neural progenitors, we have looked at these cells in animals that have retinal degeneration…and we can see very significant rescue of their activity.”

“We also have a program that we are pursuing using these photoreceptor progenitors. When you inject these into animals subretinally, what we were able to actually see here in the first week…the cells incorporating into the retina and within only three weeks you can see them moving into the outer nucleated layer and integrating.”

“We are also studying the photoreceptor progenitors. We are also looking to see if we can recover visual function and retinal structure using those. We also want to test those both in vitro and in vivo in terms of using conditioned media in the secreted factors. We are also studying our ganglial progenitors and we are continuing to look at those in animals for prolonged term survival of the transplanted cells, as well as for the protection or replacement of the host ganglial cells. We are also looking at using these cells in the optic nerve regeneration model.”

More recently, the company updated the status of its progenitor programs in its recent Form 10-K for 2013[5]:

We have developed a human photoreceptor progenitor cell. We believe that our photoreceptor progenitor cells, [derived from embryonic stem cells (hESCs)], are unique with respect to both the markers they express as well as their plasticity, meaning that they can differentiate into both rods and cones, and therefore provide a viable source of new photoreceptors for retinal repair. In addition, the photoreceptor progenitors appear to secrete neuroprotective factors, and have the ability to phagocytose (digest) such materials as the drusen deposits that build up in the eyes of dry AMD patients, and so may provide additional benefits beyond forming new photoreceptors when injected into the subretinal space in the eyes of patients. We will continue our preclinical investigation in animal models, establish appropriate correlation between integration of the transplanted cells and visual function in the animals, and then consider preparation of an IND and/or IMPD application to commence clinical studies with these cells.

In the United States alone, approximately 100,000 people are legally blind from glaucoma. The only proven treatment is drug therapy or surgically lowering the intraocular pressure, but many patients lose vision despite receiving these treatments. In glaucoma, retinal ganglion cells degenerate before photoreceptors are lost. We are currently conducting pre-clinical research and development activities regarding differentiation of stem cells into retinal ganglion cells and demonstration of the ability of those cells to protect against elevated intraocular pressure in glaucoma models. We have succeeded in generating a unique human ganglion progenitor cell which, when injected in animal models of glaucoma, appear to protect against damage and to form new ganglion nerve cells. We will continue our preclinical investigation in animal models, establish appropriate correlation between integration and visual function in the animals, and then consider preparation of an IND and/or IMPD application to commence clinical studies with these cells.

In the course of our work with various progenitor cells for treating ocular degenerative diseases, we have discovered that certain progenitor cells not only have the ability to participate directly in the formation of new tissue in the eye, but also were able to exert a neuroprotective effect that reduces the rate of degeneration of native photoreceptors in the animals’ eyes, for example, in animal models of macular degeneration. These cells appeared to also be a source of neuroprotective paracrine factors; biological agents which may themselves be useful as drugs. Further, we observed that these protective effects were uniquely produced by particular progenitor cell sub-types. The restriction of this protective activity to only a certain progenitor cell type permits us to examine which factors are differentially produced by these cells as compared with other closely related progenitor cells which do not seem to secrete any protective agents. We anticipate that the neuroprotective agent(s) that we may ultimately develop as drug candidates may be useful not only in retinal diseases and dystrophies, but may have broader applications in central nervous system and peripheral nervous system diseases and disorders, including diseases causing cognitive function impairment, movement disorders such as Parkinson’s Disease, and ischemic events such as caused by stroke.

This progenitor cell work is in the pre-clinical stages and not yet ready for human clinical testing.

In early February, California Stem Cell, Inc. (CSC) announced the initiation of a collaborative study with the University of California, Irvine (UCI), to create a transplantable 3D retinal tissue.[6] The study, funded by a $4.5 million grant from the California Institute of Regenerative Medicine (CIRM), is a continuation of methods pioneered by CSC scientists and researchers at UCI in 2010 [7], and will investigate the potential of improving a patient’s visual function by transplanting human stem cell-derived three-dimensional (3D) retinal tissue into their retina.

California Stem Cell, using its specialized cGMP manufacturing facility and regulatory personnel, will differentiate human stem cells into retinal progenitor cells. These cells will then be co-cultured with stem cell-derived retinal pigment epithelium to create a 3D tissue structure suitable for transplantation. Proof of concept in-vivo studies will take place at UCI’s Sue & Bill Gross Stem Cell Research Center, under the auspices of Dr. Magdalene J. Seiler. Transplants are expected to develop into mature retina, interact with the host tissue, and subsequently improve the vision of retinal degenerative recipients. The study, if successful, could lead to new treatments for incurable retinal diseases such as retinitis pigmentosa and age-related macular degeneration, leading causes of vision loss for people age 50 and older.

CSC President & CEO Hans Keirstead, Ph.D. (formally with UCI) will lead the study’s work at CSC. “This study establishes a valuable partnership between ourselves and a team of very talented scientists at a university known for its excellence in research,” said Keirstead. “California Stem Cell looks forward to making a meaningful contribution to work that has the potential to help millions suffering from life-altering retinal diseases.”

This work is in the very early pre-clinical animal testing stages.

jCyte has developed methods, that utilize human, fetal-derived, retinal progenitor cells (hRPCs), that have been partially developed into retinal cells, to activate degenerating host photoreceptors and replace and/or reactivate, in this case the cones, lost to disease, in those with retinitis pigmentosa (RP).

JCyte’s work will initially target cone cells because they provide central vision and the ability to read, drive and recognize faces. (Although, rod cells should also be affected.) The work will include growing pharmaceutical-grade progenitors, testing them for safety and efficacy in animal models, and then launching a clinical study for severely impaired RP patients, to prove safety and efficacy in humans.

jCyte’s research is currently supported by several resources including The Discovery Eye Foundation and two awards from CIRM (the California Institute for Regenerative Medicine), including a $4 million CIRM’s Early Translation II Award [8] and more recently a $17 million Therapy Development grant [9]. Dr. Klassen’s project was also accepted into the Therapeutics for Rare and Neglected Diseases (TRND) program established by the National Institutes of Health to speed the development of new treatments for rare and neglected diseases. TRND will provide him with specialized expertise and resources to help advance his efforts [10].

Dr. Klassen intends to seek further funding to translate this cutting-edge discovery into clinical drug and cell therapy, via submission to the FDA to launch a clinical trial.

In an update posted on his website in November 2013 [11], Dr. Klassen reported that, “The team remains hard at work in the effort to bring retinal progenitor cells to clinical trials. The work being conducted now is centered on accumulating the evidence we need to provide to the FDA in order to get approval. Prior work has set the stage by showing what is possible using these cells, but now everything has to be repeated on a larger scale, with extensive documentation, and using the same cells that will be used in patients. This is known as the Pre-Clinical Phase of the project and, as such, it is the stage just before trials begin. The major objective of the Pre-Clinical Phase is to demonstrate safety and efficacy of the product in animal models as a basis for initiating studies in humans. It is a lot of work and would take a long time if everything was done sequentially so, with the help of CIRM, we are approaching the various projects in parallel to accelerate progress. Still, it can be expected to take about a year to complete. As the results of theses studies come in, they will be collected to form the body of what is known as an Investigational New Drug (IND) application, which is the formal document that goes to the FDA.”

If things go as planned, jCyte should complete its pre-clinical work and be prepared to submit its NDA by late 2014, for a human clinical trial for patients with severe RP. The patients will be injected with hRPCs in their worst-seeing eye to determine safety and efficacy, hopefully, beginning sometime in early 2015.

Other targeted conditions, once safety and efficacy are shown in the RP trial, could include geographic atrophy (GA) found in dry AMD, and replacing destroyed photoreceptors in those suffering from Stargardt’s Disease (Stargardt’s Macular Dystrophy [SMD]).

One of the more ambitious stem-cell treatments nearing human study is being developed by ReNeuron, a company from the United Kingdom. Its retinal progenitor treatment replaces photoreceptors lost to retinitis pigmentosa. When transplanted in the retina, ReNeuron researchers believe that the partially developed cells will mature into fully functional photoreceptors. The company hopes to launch a clinical trial this year. Previously funded by the Foundation Fighting Blindness, Michael Young, Ph.D., of Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, conducted much of the research making this treatment approach possible. His work included the development of a biodegradable scaffold for growing and organizing the cells prior to transplantation. The structure increases the chances of survival and integration of the therapeutic cells.[12]

In September 2013 [13], ReNeuron was granted an orphan designation by the U.S. Food and Drug Administration (FDA) and the European Commission for its emerging retinitis pigmentosa (RP) treatment, known as ReN003 (hRPCs derived from fetal tissue). Given to potential treatments for rare conditions that are life-threatening or chronically debilitating, “orphan” status provides a company with development incentives, tax credits and market protections for therapy development.

The designation bolsters ReNeuron’s plan to launch a Phase I/II clinical trial for ReN003 in mid-2014. The company is partnering with the Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, to develop the treatment. According to Dr. Young, a lead investigator on the project at Schepens, ReNeuron plans to initiate the study at the Mass Eye & Ear Infirmary in the United States, and later extend it to sites in Europe.

There are also several university-based projects underway, including that of Prof. Robin Ali at University College London [14], and in the lab of Thomas Reh at the University of Washington in Seattle [15].

In addition to the programs using retinal progenitor cells, there are several efforts underway to provide vision to those who have lost it because of damaged or destroyed photoreceptors.

I will list just a few of these:

The Use of Stem Cells – Several companies/institutions are in clinical trials [16] using stem cells to treat those with Stargardt’s disease, dry AMD, and retinitis pigmentosa.

The Use of Gene Therapy – Gene therapy is also actively being used [17] in the treatment of dry (and wet) AMD, Stargardt’s disease, and retinitis pigmentosa.

Optogenetics – An offshoot of gene therapy, wherein a photoactive dye is delivered via a virus carrier into neural tissue (ganglion cells, bypassing damaged photoreceptors) and is activated by light signals sent into these activated tissues, which in turn sends electrical signals along the optic nerve to the brain [18]. Several companies and institutions are currently doing animal work in preparation for undertaking human trials, including Eos Neuroscience, Gensight Biologics, RetroSense Therapeutics, and the Institute de la Vision in Paris [19], along with work being done at Cornell Univ. by Dr. Sheila Nirenberg [20].

Retinal Implants – Several companies have developed and are currently marketing devices that sit on the surface of the retina and use cameras, or other optical means to send a signal to the electrodes implanted on the retinal surface that in turn sends a signal to the brain simulating visual inputs [21].

Retinal Regeneration – a laser treatment whereby a mild laser dose is imposed onto the RPE layer as a means of “stimulating” the RPE cells to release enzymes that are capable of “cleaning” Bruchs membrane, thereby rejuvenating the retina and restoring vision [22].

I personally believe that the use of retinal progenitor cells to rejuvenate or repair damaged photoreceptor cells in those people with degenerative retinal diseases, is an important step in the right direction. If, in the clinical trials scheduled to begin in late-2014 or 2015, this technique does restore vision in people that have lost it due to damaged or destroyed photoreceptors, it will become one of the great advances in the battle of fighting blindness.

1. Photoreceptor Differentiation following Transplantation of Allogeneic Retinal Progenitor Cells to the Dystrophic Rhodopsin Pro347Leu Transgenic Pig, Klassen &Young, et al, Stem Cells Int., Vol 2012, January 2012.

2. Stem Cells in Ophthalmology Update 25: ACT Patient in Dry AMD Trial Goes from 20/400 to 20/40!, Irv Arons’ Journal, May 17, 2013

3. Transcript of ACT’s Annual Shareholder Meeting, October 22, 2013

4. Slide 26 from ACT’s Presentation at BioTech Showcase 2014, January 14, 2014.

5. ACT Form 10-K, April 1, 2014

6. Restoring vision by sheet transplants of retinal progenitors and retinal pigment epithelium (RPE) derived from human embryonic stem cells (hESCs), CIRM Grant.

7. Three-dimensional early retinal progenitor 3D tissue constructs derived from human embryonic stem cells, Gabriel Nistor et al, Journal of Neuroscience Methods, April 2010.

8. Human retinal progenitor cells as candidate therapy for retinitis pigmentosa: Early Translational II, CIRM. October 2010

9. Retinal progenitor cells for treatment of retinitis pigmentosa: Disease Team Therapy Development – Research, CIRM, September, 2012

10. Use of retinal progenitor cells for the treatment of retinitis pigmentosa

Henry J. Klassen, M.D., Ph.D.,, Therapeutics for Rare and Neglected Diseases(TRND) program at the NIH’s National Center for Advancing Translational Sciences (NCATS), October 2, 2013

11. November 2013 Update from Dr. Henry Klassen, jCyte News, November, 2013

12. Several New Stem Cell Clinical Trials Poised to Begin in Two to Three Years, Dr. Stephen Rose, Eye on the Cure (FFB), July 12, 2013

13. Orphan Designation Boosts Clinical Development of RP Stem Cell Therapy, FFB News, September 11, 2013

14. New Breakthrough: transplantation of photoreceptors from retina grown `in a dish’, Prateek Buch, UCL EyeTherapy blog, July 22, 2013

15. Efficient generation of retinal progenitor cells from human embryonic stem cells, Lamba et al, University of Washington, Seattle, WA,  PNAS, July 2006

16. Stem Cell/Cell Therapy in Ophthalmology — Ongoing & Completed Clinical Trial Details, Irv Arons’ Journal, January 2014

17. Gene Therapy in Ophthalmology — Ongoing Clinical Trial Details, Irv Arons’ Journal, April 2014

18. Gene Therapy in Ophthalmology Update 18: A RetroSense (and Optogenetics) Update, Irv Arons’ Journal, March 20, 2013

19. Gene Therapy Companies/Institutions Active in Ophthalmology, Irv Arons’ Journal, January 2014

20. A New Technique for Restoring Normal Vision to the Blind: The Technology of Prof. Sheila Nirenberg of Weill Cornell Medical School, Irv Arons’ Journal, May 7, 2013

21. Ibid, section on Retinal Prostheses

22. Ellex 2RT Updated Clinical Results: ARVO 2011, Irv Arons’ Journal, May 2011

By Mark Hillen, Editor

The Ophthalmologist, February 12, 2014

When a man tells you that, in ten years’ time, he envisages treating retinal diseases with a tiny inkjet printer head, you begin to wonder if he’s been drinking strong coffee with too much gusto that morning. But if that man is Keith Martin, Professor of Ophthalmology at the University of Cambridge, you need to revisit that diagnosis.

Martin has the only inkjet printer in the world that can print retinal ganglion cells (RGCs) and glia, and deliver a live product. He and colleagues Barbara Lorber, Wen-Kai Hsiao and Ian Hutchings recently published the method in Biofabrication (1), and it’s a story of happenstance, cross-pollination of ideas, and just giving things a go. Conventional wisdom had it that the cells of the rat central nervous system (CNS) are too fragile to be fired down a piezoelectric printer head; that printed glia wouldn’t function to provide support and nutrition to neurons, and that printed RGCs wouldn’t grow neurites (which are essential to communicate with other cells). Martin and colleagues did the experiments anyway. And they worked.

As loss of certain retinal cell types is characteristic of many eye diseases, from age-related macular degeneration to glaucoma, the possibility of replacing them with cultured cells that function in situ is exciting. We spoke to Martin about it.

Barbara has been working in my lab for a number of years, trying to get RGCs to regenerate but this particular project was pure opportunism. Basically, it stems from a conversation with her husband, who works on inkjet printing technology, on the overlap between what we do and what he does. It turned into a Friday afternoon experiment: they decided to see if the cells could survive the printing process. Much to everyone’s surprise, they did. So it started there.

There are no reports in the literature of adult CNS cell printing being achieved successfully, so this is a first – we don’t know how many people have tried and failed.

The technique that we’ve developed involves separating adult retinal cells and loading them into a specially built piezoelectric inkjet printing device. (See illustration.) This allows us to fire cells out of the print head (Figure 1) at about 30 mph, that’s about a thousand cells per second, and we can print them in precise patterns (Figure 2). This potentially gives us a way to recreate adult neuronal structures using printing technology.

(Open in a new tab to enlarge each of the figures and the illustration above.)

Well, that’s a long way off. There are a number of more immediate ways that this might be useful. For example, printing retinal pigment epithelial (RPE) cells or photoreceptors, cell types that are lost specifically in certain conditions. One could envisage using the printing technology to create an implant outside the eye and then inserting it. With further miniaturization, it may be possible to spray cells within the eye, as part of vitreoretinal surgery. That’s what we’re looking to do, but it is far too early to talk about achieving it.

Yes. I think the biggest advances will come not from using one of these technologies alone, but by combining them, coming at the problem from different approaches. The interface between the electronic and the biological approaches is one such combination.

We’re certainly looking at other cell types. Glial-neuronal interactions are obviously very important for the health of neurons – they can’t function in the long term without the support of glia. In terms of regeneration, the glial effect really promotes the axonal regeneration; we saw far better axon regeneration from the RGCs.

We are a long way from being able to replicate the vasculature. But there are other ways of stimulating blood vessel growth. In degenerative diseases, the blood supply is not so much of a problem. For ischemic conditions it might be, but we’re sticking to the neurons and glia just at the moment.

We’d like to be using this as part of the treatment for regenerating the retina – that’s our main goal. As I said, I don’t think that this is the whole solution but it will help. We will look at manufacturing artificial neuronal tissue and also at repairing what’s already there.

Yes, that’s the timescale we’re looking at. In terms of printing RPEs and photoreceptors it might even be a bit quicker than that, as those are more straightforward cell types. We started in RGCs because my main interest is in glaucoma – a crucial element in the pathophysiology of all forms of glaucoma is RGC death. However, people who have looked at the work are saying that it may well be more relevant to replacing RPE and photoreceptors.

I think that’s perfectly possible, and it may well be easier than the neuronal cell types. I’m not sure anyone has tried as yet. This is a very adaptable and modifiable technology and if fragile neurons can survive it, then I’m sure that corneal cells will.

Reference

“Adult rat retinal ganglion cells and glia can be printed by piezoelectric inkjet printing”, B. Lorber et al., Biofabrication, 6, 015001 Epub ahead of print] (2013). doi:10.1088/1758-5082/6/1/015001.

We have investigated whether inkjet printing technology can be extended to print cells of the adult rat central nervous system (CNS), retinal ganglion cells (RGC) and glia, and the effects on survival and growth of these cells in culture, which is an important step in the development of tissue grafts for regenerative medicine, and may aid in the cure of blindness. We observed that RGC and glia can be successfully printed using a piezoelectric printer. Whilst inkjet printing reduced the cell population due to sedimentation within the printing system, imaging of the printhead nozzle, which is the area where the cells experience the greatest shear stress and rate, confirmed that there was no evidence of destruction or even significant distortion of the cells during jet ejection and drop formation. Importantly, the viability of the cells was not affected by the printing process. When we cultured the same number of printed and non-printed RGC/glial cells, there was no significant difference in cell survival and RGC neurite outgrowth. In addition, use of a glial substrate significantly increased RGC neurite outgrowth, and this effect was retained when the cells had been printed. In conclusion, printing of RGC and glia using a piezoelectric printhead does not adversely affect viability and survival/growth of the cells in culture. Importantly, printed glial cells retain their growth-promoting properties when used as a substrate, opening new avenues for printed CNS grafts in regenerative medicine.