New therapy may improve stem cell transplants for blood cancers
Ivan Dimov, Jeroen Bekaert and Nate Fernhoff - pictured here - recognized the need for a more effective cell sorting technology to reduce the risk of Graft vs Host disease, which affects many cancer patients after receiving stem cell transplants.
In 2018, Robyn was diagnosed with myelofibrosis, a blood cancer causing chronic inflammation and scarring. As a research scientist by training, she knew she had limited options. A stem cell transplant is a terminally ill patient's best chance for survival against blood cancers, including leukaemia. It works by destroying a patient's cancer cells and replacing them with healthy cells from a donor.
However, there is a huge risk of Graft vs Host disease (GVHD), which affects around 30-40% of recipients. Patients receive billions of cells in a stem cell transplant but only a fraction are beneficial. The rest can attack healthy tissue leading to GVHD. It affects the skin, gut and lungs and can be truly debilitating.
Currently, steroids are used to try and prevent GVHD, but they have many side effects and are effective in only 50% of cases. “I spoke with my doctors and reached out to patients managing GVHD,” says Robyn, who prefers not to use her last name for privacy reasons. “My concerns really escalated for what I might face post-transplant.”
Then she heard about a new highly precise cell therapy developed by a company called Orca Bio, which gives patients more beneficial cells and fewer cells that cause GVHD. She decided to take part in their phase 2 trial.
How It Works
In stem cell transplants, patients receive immune cells and stem cells. The donor immune cells or T cells attack and kill malignant cells. This is the graft vs leukaemia effect (GVL). The stem cells generate new healthy cells.
Unfortunately, T cells can also cause GVHD, but a rare subset of T cells, called T regulatory cells, can actually prevent GVHD.
Orca’s cell sorting technology distinguishes T regulatory cells from stem cells and conventional T cells on a large scale. It’s this cell sorting technology which has enabled them to create their new cell therapy, called Orca T. It contains a precise combination of stem cells and immune cells with more T regulatory cells and fewer conventional T cells than in a typical stem cell transplant.
“Ivan Dimov’s idea was to spread out the cells, keep them stationary and then use laser scanning to sort the cells,” explains Nate Fernhoff, co-founder of Orca Bio. “The beauty here is that lasers don't care how quickly you move them.”
Over the past 40 years, scientists have been trying to create stem cell grafts that contain the beneficial cells whilst removing the cells that cause GVHD. What makes it even harder is that most transplant centers aren’t able to manipulate grafts to create a precise combination of cells.
Innovative Cell Sorting
Ivan Dimov, Jeroen Bekaert and Nate Fernhoff came up with the idea behind Orca as postdocs at Stanford, working with cell pioneer Irving Weissman. They recognised the need for a more effective cell sorting technology. In a small study at Stanford, Professor Robert Negrin had discovered a combination of T cells, T regulatory cells and stem cells which prevented GVHD but retained the beneficial graft vs leukaemia effect (GVL). However, manufacturing was problematic. Conventional cell sorting is extremely slow and specific. Negrin was only able to make seven highly precise products, for seven patients, in a year. Annual worldwide cases of blood cancer number over 1.2 million.
“We started Orca with this idea: how do we use manufacturing solutions to impact cell therapies,” co-founder Fernhoff reveals. In conventional cell sorting, cells move past a stationary laser which analyses each cell. But cells can only be moved so quickly. At a certain point they start to experience stress and break down. This makes it very difficult to sort the 100 billion cells from a donor in a stem cell transplant.
“Ivan Dimov’s idea was to spread out the cells, keep them stationary and then use laser scanning to sort the cells,” Fernhoff explains. “The beauty here is that lasers don't care how quickly you move them.” They developed this technology and called it Orca Sort. It enabled Orca to make up to six products per week in the first year of manufacturing.
Every product Orca makes is for one patient. The donor is uniquely matched to the patient. They have to carry out the cell sorting procedure each time. Everything also has to be done extremely quickly. They infuse fresh living cells from the donor's vein to the patient's within 72 hours.
“We’ve treated almost 200 patients in all the Orca trials, and you can't do that if you don't fix the manufacturing process,” Fernhoff says. “We're working on what we think is an incredibly promising drug, but it's all been enabled by figuring out how to make a high precision cell therapy at scale.”
Clinical Trials
Orca revealed the results of their phase 1b and phase 2 trials at the end of last year. In their phase 2 trial only 3% of the 29 patients treated with Orca T cell therapy developed chronic GVHD in the first year after treatment. Comparatively, 43% of the 95 patients given a conventional stem cell transplant in a contemporary Stanford trial developed chronic GVHD. Of the 109 patients tested in phase 1b and phase 2 trials, 74% using Orca T didn't relapse or develop any form of GVHD compared to 34% in the control trial.
“Until a randomised study is done, we can make no assumption about the relative efficacy of this approach," says Jeff Szer, professor of haematology at the Royal Melbourne Hospital. "But the holy grail of separating GVHD and GVL is still there and this is a step towards realising that dream.”
Stan Riddell, an immunology professor, at Fred Hutchinson Cancer Centre, believes Orca T is highly promising. “Orca has advanced cell selection processes with innovative methodology and can engineer grafts with greater precision to add cell subsets that may further contribute to beneficial outcomes,” he says. “Their results in phase 1 and phase 2 studies are very exciting and offer the potential of providing a new standard of care for stem cell transplant.”
However, though it is an “intriguing step,” there’s a need for further testing, according to Jeff Szer, a professor of haematology at the Peter MacCallum Cancer Centre at the Royal Melbourne Hospital.
“The numbers tested were tiny and comparing the outcomes to anything from a phase 1/2 setting is risky,” says Szer. “Until a randomised study is done, we can make no assumption about the relative efficacy of this approach. But the holy grail of separating GVHD and GVL is still there and this is a step towards realising that dream.”
The Future
The team is soon starting Phase 3 trials for Orca T. Its previous success has led them to develop Orca Q, a cell therapy for patients who can't find an exact donor match. Transplants for patients who are only a half-match or mismatched are not widely used because there is a greater risk of GVHD. Orca Q has the potential to control GVHD even more and improve access to transplants for many patients.
Fernhoff hopes they’ll be able to help people not just with blood cancers but also with other blood and immune disorders. If a patient has a debilitating disease which isn't life threatening, the risk of GVHD outweighs the potential benefits of a stem cell transplant. The Orca products could take away that risk.
Meanwhile, Robyn has no regrets about participating in the Phase 2 trial. “It was a serious decision to make but I'm forever grateful that I did,” she says. “I have resumed a quality of life aligned with how I felt pre-transplant. I have not had a single issue with GVHD.”
“I want to be able to get one of these products to every patient who could benefit from it,” Fernhoff says. “It's really exciting to think about how Orca's products could be applied to all sorts of autoimmune disorders.”
Last month, a paper published in Cell by Harvard biologist David Sinclair explored root cause of aging, as well as examining whether this process can be controlled. We talked with Dr. Sinclair about this new research.
What causes aging? In a paper published last month, Dr. David Sinclair, Professor in the Department of Genetics at Harvard Medical School, reports that he and his co-authors have found the answer. Harnessing this knowledge, Dr. Sinclair was able to reverse this process, making mice younger, according to the study published in the journal Cell.
I talked with Dr. Sinclair about his new study for the latest episode of Making Sense of Science. Turning back the clock on mouse age through what’s called epigenetic reprogramming – and understanding why animals get older in the first place – are key steps toward finding therapies for healthier aging in humans. We also talked about questions that have been raised about the research.
Show links:
Dr. Sinclair's paper, published last month in Cell.
Recent pre-print paper - not yet peer reviewed - showing that mice treated with Yamanaka factors lived longer than the control group.
Dr. Sinclair's podcast.
Previous research on aging and DNA mutations.
Dr. Sinclair's book, Lifespan.
Harvard Medical School
Breakthrough therapies are breaking patients' banks. Key changes could improve access, experts say.
Single-treatment therapies are revolutionizing medicine. But insurers and patients wonder whether they can afford treatment and, if they can, whether the high costs are worthwhile.
CSL Behring’s new gene therapy for hemophilia, Hemgenix, costs $3.5 million for one treatment, but helps the body create substances that allow blood to clot. It appears to be a cure, eliminating the need for other treatments for many years at least.
Likewise, Novartis’s Kymriah mobilizes the body’s immune system to fight B-cell lymphoma, but at a cost $475,000. For patients who respond, it seems to offer years of life without the cancer progressing.
These single-treatment therapies are at the forefront of a new, bold era of medicine. Unfortunately, they also come with new, bold prices that leave insurers and patients wondering whether they can afford treatment and, if they can, whether the high costs are worthwhile.
“Most pharmaceutical leaders are there to improve and save people’s lives,” says Jeremy Levin, chairman and CEO of Ovid Therapeutics, and immediate past chairman of the Biotechnology Innovation Organization. If the therapeutics they develop are too expensive for payers to authorize, patients aren’t helped.
“The right to receive care and the right of pharmaceuticals developers to profit should never be at odds,” Levin stresses. And yet, sometimes they are.
Leigh Turner, executive director of the bioethics program, University of California, Irvine, notes this same tension between drug developers that are “seeking to maximize profits by charging as much as the market will bear for cell and gene therapy products and other medical interventions, and payers trying to control costs while also attempting to provide access to medical products with promising safety and efficacy profiles.”
Why Payers Balk
Health insurers can become skittish around extremely high prices, yet these therapies often accompany significant overall savings. For perspective, the estimated annual treatment cost for hemophilia exceeds $300,000. With Hemgenix, payers would break even after about 12 years.
But, in 12 years, will the patient still have that insurer? Therein lies the rub. U.S. payers, are used to a “pay-as-you-go” model, in which the lifetime costs of therapies typically are shared by multiple payers over many years, as patients change jobs. Single treatment therapeutics eliminate that cost-sharing ability.
"As long as formularies are based on profits to middlemen…Americans’ healthcare costs will continue to skyrocket,” says Patricia Goldsmith, the CEO of CancerCare.
“There is a phenomenally complex, bureaucratic reimbursement system that has grown, layer upon layer, during several decades,” Levin says. As medicine has innovated, payment systems haven’t kept up.
Therefore, biopharma companies begin working with insurance companies and their pharmacy benefit managers (PBMs), which act on an insurer’s behalf to decide which drugs to cover and by how much, early in the drug approval process. Their goal is to make sophisticated new drugs available while still earning a return on their investment.
New Payment Models
Pay-for-performance is one increasingly popular strategy, Turner says. “These models typically link payments to evidence generation and clinically significant outcomes.”
A biotech company called bluebird bio, for example, offers value-based pricing for Zynteglo, a $2.8 million possible cure for the rare blood disorder known as beta thalassaemia. It generally eliminates patients’ need for blood transfusions. The company is so sure it works that it will refund 80 percent of the cost of the therapy if patients need blood transfusions related to that condition within five years of being treated with Zynteglo.
In his February 2023 State of the Union speech, President Biden proposed three pilot programs to reduce drug costs. One of them, the Cell and Gene Therapy Access Model calls on the federal Centers for Medicare & Medicaid Services to establish outcomes-based agreements with manufacturers for certain cell and gene therapies.
A mortgage-style payment system is another, albeit rare, approach. Amortized payments spread the cost of treatments over decades, and let people change employers without losing their healthcare benefits.
Only about 14 percent of all drugs that enter clinical trials are approved by the FDA. Pharma companies, therefore, have an exigent need to earn a profit.
The new payment models that are being discussed aren’t solutions to high prices, says Bill Kramer, senior advisor for health policy at Purchaser Business Group on Health (PBGH), a nonprofit that seeks to lower health care costs. He points out that innovative pricing models, although well-intended, may distract from the real problem of high prices. They are attempts to “soften the blow. The best thing would be to charge a reasonable price to begin with,” he says.
Instead, he proposes making better use of research on cost and clinical effectiveness. The Institute for Clinical and Economic Review (ICER) conducts such research in the U.S., determining whether the benefits of specific drugs justify their proposed prices. ICER is an independent non-profit research institute. Its reports typically assess the degrees of improvement new therapies offer and suggest prices that would reflect that. “Publicizing that data is very important,” Kramer says. “Their results aren’t used to the extent they could and should be.” Pharmaceutical companies tend to price their therapies higher than ICER’s recommendations.
Drug Development Costs Soar
Drug developers have long pointed to the onerous costs of drug development as a reason for high prices.
A 2020 study found the average cost to bring a drug to market exceeded $1.1 billion, while other studies have estimated overall costs as high as $2.6 billion. The development timeframe is about 10 years. That’s because modern therapeutics target precise mechanisms to create better outcomes, but also have high failure rates. Only about 14 percent of all drugs that enter clinical trials are approved by the FDA. Pharma companies, therefore, have an exigent need to earn a profit.
Skewed Incentives Increase Costs
Pricing isn’t solely at the discretion of pharma companies, though. “What patients end up paying has much more to do with their PBMs than the actual price of the drug,” Patricia Goldsmith, CEO, CancerCare, says. Transparency is vital.
PBMs control patients’ access to therapies at three levels, through price negotiations, pricing tiers and pharmacy management.
When negotiating with drug manufacturers, Goldsmith says, “PBMs exchange a preferred spot on a formulary (the insurer’s or healthcare provider’s list of acceptable drugs) for cash-base rebates.” Unfortunately, 25 percent of the time, those rebates are not passed to insurers, according to the PBGH report.
Then, PBMs use pricing tiers to steer patients and physicians to certain drugs. For example, Kramer says, “Sometimes PBMs put a high-cost brand name drug in a preferred tier and a lower-cost competitor in a less preferred, higher-cost tier.” As the PBGH report elaborates, “(PBMs) are incentivized to include the highest-priced drugs…since both manufacturing rebates, as well as the administrative fees they charge…are calculated as a percentage of the drug’s price.
Finally, by steering patients to certain pharmacies, PBMs coordinate patients’ access to treatments, control patients’ out-of-pocket costs and receive management fees from the pharmacies.
Therefore, Goldsmith says, “As long as formularies are based on profits to middlemen…Americans’ healthcare costs will continue to skyrocket.”
Transparency into drug pricing will help curb costs, as will new payment strategies. What will make the most impact, however, may well be the development of a new reimbursement system designed to handle dramatic, breakthrough drugs. As Kramer says, “We need a better system to identify drugs that offer dramatic improvements in clinical care.”