You Might Also Like: Clinical Trialblazers

**Alberto Grignolo** (0:00)
Welcome to Clinical Trial Blazers, a podcast by Parcel Biotech, where we dive deep into the journeys of the industry leaders who are shaping clinical research and biotech innovation. I am your host, Alberto Grignolo. If you enjoy these conversations, please take a moment to rate, review, and follow the podcast on your favorite platform. It really helps more listeners discover the show.
Today on Clinical Trial Blazers, my guest is Reenie McCarthy, the CEO of Mighty Therapeutics, formerly known as Stealth BioTherapeutics. Reenie's journey to the CEO role reflects a steady progression from functional leadership into full enterprise responsibility. In 2025, she successfully led the company through one of the most challenging paths in biotech, developing and ultimately securing FDA approval for L-amipratide, a therapy for Barth syndrome, a rare and historically incurable disease. This process required not just scientific and regulatory rigor, but persistence and the ability to navigate setbacks and funding pressures. Reenie previously led the U.S.-based investment team of Morningside Ventures from 1993 through 2015
Reenie brings a pragmatic and determined leadership style, and today we'll explore the key moments and decisions that shaped her path, including how she turned a regulatory setback challenge into an opportunity. Reenie McCarthy, welcome.

**Reenie McCarthy** (1:26)
Thank you. I really appreciate the opportunity to join you today.

**Alberto Grignolo** (1:30)
You recently changed the company name from Stealth BioTherapeutics to Mighty Therapeutics. You've gone from Stealthy to Mighty. So what prompted that change and what does the new name signal about the company's next chapter?

**Reenie McCarthy** (1:42)
You know, really, the name change was prompted as a means to celebrate the patient community that has really led us to this approval. When you think about a disease like Barth syndrome, it is very, very rare.
This is a very small group of patients and their families working, you know, towards therapeutic options for which there have previously been none. And even more broadly in the mitochondrial disease community, you've got similarly a collection of very small, very rare mitochondrial diseases. We've been so impressed and inspired and, you know, motivated really by these patient communities that as we bring our science out of, you know, stealth mode as it were really to the first approval of the first mitochondrial targeted therapeutic, we wanted to celebrate those patient communities. And that's really the choice of name reflects that these are small, but very mighty communities. And we hope we can live up to their grit and determination as we move forward.

**Alberto Grignolo** (2:39)
When you stepped into the CEO role at Stealth, which is now Mighty, what were the immediate priorities and how did you or how quickly did you realize the hardest part of the job? Did you realize that quickly or more gradually over time? What made the job tough if it did?

**Reenie McCarthy** (2:54)
I was really stepping in on an interim basis. We were looking to sort of stabilize leadership at the company and define strategic priorities going forward, working with the management team. When you talk about diseases of mitochondrial dysfunction, the potential is almost limitless in terms of mitochondria being involved in almost every aspect of human health and disease. And so I think that partnering with the management team that had very seasoned executives, drug developers, and defining that vision and moving forward was the first priority. I was really gratified to be asked by my co-executives to stay on in the role, really moving from interim to full-time permanent CEO.
And I would say one of the biggest challenges was the learning curve that took, great learning all things mitochondria, deep dive into the science and also into aspects of drug development that as an investor and a board member, we certainly know of, but you don't know the nitty-gritty day-to-day aspects.

**Alberto Grignolo** (3:58)
Was Stealth initially funded by Morningside where you had worked for many years?

**Reenie McCarthy** (4:02)
Yeah. So I remember the first trip down to meet the scientific founder in New York. So this was technology that was discovered by scientists at Wow Cornell Medical and Institute to Research to Montreal. So I remember those early meetings and we again, were just really intrigued by the potential to target mitochondria, previously undruggable target, but so centrally important to human health and ultimately human disease.

**Alberto Grignolo** (4:29)
I'd like to go back to the early part of your career. I'm interested in what drew you into the life sciences industry and how did your path evolve towards a broader leadership role. You've already made some allusion to it, I'm interested in going upstream from that. How did you become interested in the life sciences in the first place?

**Reenie McCarthy** (4:46)