Ossium Health CEO Kevin Caldwell on reengineering bone marrow for immune reset, aging intervention and regenerative equity.
Ossium Health, a clinical-stage bioengineering company based in the US, is pioneering a new category in biobanking with its development of the world’s first bone marrow bank sourced from deceased organ donors. Founded with the mission to enhance human vitality and extend healthspan, Ossium secured $52 million in Series C funding in 2023 to advance its cryopreservation and cell therapy capabilities.
Now, the company is working to redefine one of medicine’s most intensive interventions – bone marrow transplantation – as a platform for longevity. If successful, Ossium’s approach could bring immune resets to the mainstream, giving millions of aging individuals the chance to rejuvenate their immune systems, prevent age-related diseases and add healthy decades to life. It’s a radical evolution from oncology to proactive aging medicine – one that could shift bone marrow transplantation from a last-resort procedure to a cornerstone of preventative healthcare.
Longevity.Technology: This week’s Vitalist Bay Summit, set in the heart of San Francisco’s life sciences innovation corridor, provides a timely forum for cross-disciplinary discussion on the convergence of biology, technology and capital in service of human longevity. Kevin Caldwell, Ossium’s co-founder and CEO, will take the stage later today with a talk titled From Saving Lives to Extending Health, exploring how Ossium’s origins in oncology have informed its ambition to make regenerative therapies more accessible and scalable. His contribution ties in with the event’s emphasis on translational science and systemic longevity solutions – offering not a radical departure from Ossium’s medical roots, but rather a logical evolution. Ahead of the Summit, we sat down with Kevin Caldwell to discuss equitable access to regenerative therapies and how Ossium is working to bridge oncology and longevity.
A new age of immunological intervention
Ossium’s platform applies the combined power of cellular medicine and bioengineering to improve the health, vitality, and longevity of human beings, and Caldwell explains that since the company was founded in 2016, it has established a robust bank of bone marrow sourced from organ donors, which has been used with increasing frequency to treat blood cancer patients that need a bone marrow transplant.
Bone marrow transplantation is a life-saving intervention — but Caldwell and his team believe its long-term potential lies in prevention. “By fully replacing the patient’s immune system with that of a donor, this procedure can treat almost any blood or immune disease,” he says. “Furthermore, replacing an older individual’s immune system with that of a much younger donor essentially resets it to its younger, more effective state, preventing the onset of age-related diseases caused by a deteriorating immune system.”
Caldwell says that potential remains untapped due to the risks currently associated with the procedure. “Bone marrow transplantation is currently limited to treating life-threatening diseases due to its risks.” But Ossium is investing in breakthroughs that could make the treatment safer and more widely applicable.
“Researchers at various institutions, including Ossium, are making rapid progress on improving the safety of the procedure through strategies such as targeted conditioning regimens, improvements in graft-versus-host disease prophylaxis, and accelerated engraftment speeds,” he tells us. “We’re now following a deliberate, stepwise approach aligned with today’s regulatory and clinical realities to create a new healthcare paradigm where aging individuals have the option to proactively reset their immune systems.
“Ultimately, Ossium aims to make bone marrow transplantation a mainstream preventative therapy for restoring effective immune system function and extending healthspan.”
Equitable medicine, engineered from the get-go
Traditional registries often lack diversity, making it difficult for minority patients to find matching donors. Ossium’s model changes that, as Caldwell explains: “Since our bone marrow is sourced from the organ donor population — which better represents the makeup of the US population than the volunteer donor population — we’re unlocking a valuable new set of donor options for patients that need a stem cell transplant.”
And the company has bold ambitions for inclusivity. “As our bank scales, nearly every patient from every background will be able to source a graft quickly and reliably from our bank,” says Caldwell.
Beyond oncology: treating aging at its source
Caldwell and Ossium see their platform’s greatest promise in reversing immune aging. “The decline in immune function with age known as immunosenescence is a major contributor to low-level chronic inflammation that drives age-related diseases such as neurodegenerative diseases, cardiovascular disease, cancer and autoimmune disorders,” Caldwell told us – but he believes Ossium has found a solution.
“The scientific literature supports that completely replacing the immune system with a bone marrow transplant could cure nearly any disease of the blood and immune system, and could serve as a preventative therapy for the age-related diseases brought on by immunosenescence,” he says. “Ossium’s ultimate goal is to enable the broader aging population to reset their immune systems to a younger state, reversing immunosenescence and chronic inflammation, and thereby extending human healthspan.”
This immune reset also has applications for organ transplant patients, as Caldwell explains. “Immunosuppression-free tolerized organ transplants will be the key to improving organ transplant outcomes, including reducing rates of rejection and decreasing the toxic effects of lifelong immunosuppression,” he says. “Because most transplanted organs come from deceased donors, our work with deceased organ donor bone marrow fits naturally into this space.”
Supporting evidence is already robust, he explains. “There is already a wealth of published literature from the academic setting that supports the effectiveness of promoting tolerance in the solid organ recipient by infusing bone marrow stem cells from the same donor of the transplanted organ.”
And Ossium is uniquely positioned to act. “Because most transplanted organs come from deceased donors, our work with deceased organ donor bone marrow fits naturally into this space.”
Building the evidence
Clinical proof is central to Ossium’s future. “A key milestone we look forward to is the initial data readout from our active clinical study (PRESERVE I).”
The company’s early success has already generated momentum, says Caldwell. “After we announced the successful outcome of the first patient treated with Ossium’s bone marrow in June 2024, we saw an immediate surge of interest from hematologists and bone marrow transplant physicians looking for donors for their patients.”
Caldwell explains that this is only the beginning. “We expect that the data readout will contribute to even more momentum in the ongoing clinical study and our planned post-market study (PRESERVE II).”
A vision for longevity medicine
As Caldwell reflects on the future, he’s both pragmatic and optimistic. “Ossium is pioneering lifesaving interventions today that will help redefine tomorrow’s standards for preventative and curative care.”
He sees enormous potential to shift from crisis response to proactive wellness. “As clinical data accumulates and our bank continues to scale, we anticipate a dramatic expansion in the scope of our work — first addressing life-threatening and debilitating diseases, and eventually empowering people to proactively extend their healthspan.”
Events like the Vitalist Bay Summit highlight that possibility. “I’m particularly excited to meet and learn from the visionary leaders attending Vitalist Bay,” Caldwell says. “It’s a rare opportunity to be in a space with people who are actively reimagining what healthcare can be.”
His final hope: “I’m optimistic that we can work together to build a future where aging is no longer synonymous with health decline.” If Ossium’s vision holds, the future of aging may be shaped not by what we inherit, but by how – and when – we replace it.
