Cellular rebirth

For a bird that never actually existed, the phoenix got around. While the mythical creature’s exact origins are debated — some sources say ancient Egypt while others say ancient Greece — permutations also appeared in Russian, Chinese, Persian, Hindu and Turkish mythologies.

True to the legend of immortality, the phoenix has remained prolific throughout more than 2500 years of history. Shakespeare wrote of the phoenix in plays, Mozart mentioned it in operas, Hans Christian Andersen penned fables about it and Sylvia Plath alluded to it in poems. The symbol has endured in modern-day culture as well, emblazoned on logos, mascots, and in franchises like Marvel Comics and Harry Potter.

Egyptian lore says that at the end of its 500-year lifespan, the phoenix builds a nest, sets it on fire and allows itself to be consumed by the flames — only to be reborn from the ashes. The allure of this cyclical transformation by fire has made the bird a favorite symbol of renewal and resilience.

In the world of cell therapies, mesenchymal stem cells (MSCs) have long held a similar mystique. Since first identified in the 1960s, MSCs have fascinated researchers with their capacity for self-renewal and differentiation into multiple cell types, potential for tissue regeneration, and ability to modulate immune responses. The fire of possibility has been smoldering for decades, with the field anxiously awaiting the rise of this promising therapeutic modality.

Interestingly, some legends of the phoenix ascribed it with magical healing powers. Roman historians wrote of doctors who promoted the use of phoenix ashes to heal wounds or even stave off death completely. The scenario is oddly relatable today, as stem cell therapies continue to be clouded by unproven claims and predatory marketing, often touting them as cure-alls. (Nothing says scientific rigor like an aggressive tradeshow floor pitch for anti-aging face cream 'infused' with plant stem cells.)

After decades of research that hadn’t translated into efficacy in patients and a proliferation of unsubstantiated stem cell science, MSCs seemed stuck in therapeutic purgatory, unable to rise from the pyre and prove their validity.

But that moment came in December 2024, when Mesoblast’s Ryoncil, a bone marrow-derived MSC therapy, earned FDA approval for pediatric steroid-refractory acute graft-versus-host disease. It marked the first approval of its kind — and a fresh start for MSCs.

Of course, FDA approvals aren’t folklore; they’re grounded in strong science and robust evidence. One approval does not magically spark a fiery rebirth of an entire modality.

Yet Ryoncil’s hard-fought journey to U.S. approval offered a rare glimpse into the regulatory challenges facing MSCs — including potency, reproducibility, patient selection and trial design.

It helped clarify regulatory expectations, set a precedent for approval and perhaps even rekindled investor confidence in the power of MSC therapies. 

As you’ll read in this issue’s cover story, today’s MSC developers have taken these lessons to heart, leveraging modern technologies in hopes of igniting the next generation of more potent, targeted therapies.

And the phoenix can now add a b2b publication to its long list of cultural cameos.