Most drug candidates never make it all the way to patients. For early-stage healthcare investors, seeing a therapeutic advance from an early scientific idea through clinical development, acquisition, FDA approval, and ultimately toward commercialization is especially rare.

That is what makes the recent approval of SIMTRIYO® (centanafadine) particularly significant for Clarevia Ventures, and potentially meaningful for millions of people living with ADHD. According to the Centers for Disease Control and Prevention, an estimated 7 million U.S. children ages 3–17 and 15.5 million U.S. adults have a current ADHD diagnosis. For patients and families, finding the right treatment can be highly individualized, which makes the availability of additional treatment options especially important.

In July 2026, the FDA approved the once-daily treatment for ADHD in adults and pediatric patients ages 6 and older who weigh at least 20 kilograms. The medicine offers a distinct approach to treating ADHD, acting on norepinephrine, dopamine, and serotonin, with the goal of providing an effective option with lower abuse potential than traditional stimulant therapies.

Clarevia Partner Paul Weiss, PhD, was involved with centanafadine from its early development, helping support the science, build the investor syndicate, recruit the team, and advance the program to the point where Otsuka Pharmaceutical could take it forward. As Weiss is quick to emphasize, reaching this milestone was the result of a much broader team effort spanning scientists, company leadership, investors, clinical teams, development partners, and ultimately Otsuka. Neurovance, the Clarevia portfolio company developing centanafadine, was acquired by Otsuka in 2017. Nearly a decade later, the molecule has reached one of the most difficult milestones in drug development: FDA approval.

In this conversation, Weiss reflects on what first made the program compelling, the milestones that strengthened his conviction, the role Clarevia played in helping Neurovance mature from research into development, and what this long journey says about early-stage healthcare investing. Most importantly, he shares what it means to see a molecule he backed so early become a medicine that can now reach patients.

Most drug candidates never make it all the way to patients. When you saw that centanafadine had received FDA approval, what went through your mind—and what makes this milestone especially meaningful?

PW: First of all, it’s been a long journey. As early-stage investors, we don’t often have the opportunity to see a drug go all the way through FDA approval. We see medical devices get approved and commercialized, but with therapeutics, we typically exit around Phase 2 proof of concept. That was the case here as well, so seeing centanafadine ultimately reach FDA approval is especially meaningful.

When we set out to develop it, the goal was to create an ADHD medicine with low abuse potential and low potential for diversion. Frank Bymaster, who was involved with the company, had a long history at Eli Lilly working on Prozac and other serotonin reuptake inhibitors. Centanafadine acts on serotonin as well as norepinephrine and dopamine, so there was a strong scientific foundation behind what we were trying to accomplish.

What went through my mind when I saw the approval was really that this could become an important new medicine with broad access for patients. There can be overlap and confusion among conditions like ADHD, anxiety, and depression, so seeing new medicines approved in these areas is incredibly gratifying.

And, of course, the approval also represented an important financial milestone for us as investors, allowing us to return capital to our limited partners.

We’ve talked about centanafadine’s lower potential for abuse compared with traditional stimulant treatments. What broader problem in ADHD treatment were you hoping to address, and what made this particular approach compelling?

PW: Stimulants can be very effective for ADHD, but they come with limitations, including their abuse potential. What was compelling about centanafadine was the possibility of approaching ADHD differently.

Centanafadine belongs to a class of compounds that act on three neurotransmitter systems: norepinephrine, dopamine, and serotonin. Frank Bymaster had the scientific insight to look at the relative activity across those three systems and identify a profile that he believed was particularly well suited for ADHD.

At its core, ADHD involves dysregulation in the brain. The opportunity was to take that scientific understanding and develop a medicine designed specifically around that biology. With Frank’s insight, we were then able to put together the investment needed to advance centanafadine.

Going back to the beginning, when you first encountered the opportunity around Neurovance and centanafadine, what stood out to you about the science, the team, or the potential of the program?

PW: Neurovance emerged from a broader portfolio of compounds we were evaluating, and what really stood out was the scientific rationale behind centanafadine.

Frank Bymaster, a veteran neuroscience researcher who previously worked at Eli Lilly on several major CNS medicines, looked at the way these compounds interacted with norepinephrine, dopamine, and serotonin and believed centanafadine had the right profile for ADHD. That scientific insight gave us a strong foundation for the program.

From there, we focused on putting the right team around it: a strong syndicate of investors, along with experienced preclinical and clinical teams that could advance the asset thoughtfully and efficiently. It was really the combination of compelling science and the people involved that gave us confidence in the opportunity.

Looking back, were there particular milestones or moments of progress that strengthened your conviction in centanafadine’s potential?

PW: Yes. These kinds of indications can be challenging clinically because placebo effects can be significant, so one of the first important milestones was an early pilot study that showed encouraging results. Patients receiving the drug improved relative to placebo, which gave us confidence to invest additional capital and advance the program into Phase 2.

Another important area of progress was the formulation work. For ADHD, it is important to maintain an appropriate drug level throughout the day while allowing it to taper off later, because sleep disruption can be a concern. Developing that controlled-release profile is technically complex, and making progress there was very encouraging. Otsuka ultimately continued that work and developed the release profile used in the approved medicine.

We also conducted an abuse-liability study, which was important because reducing abuse potential was one of the goals of the program from the beginning. The results supported that objective and reinforced our confidence in centanafadine’s potential.

What does the Neurovance story illustrate about early-stage healthcare investing, particularly the importance of maintaining conviction while staying responsive to changes in the science and market?

PW: One of the biggest lessons is the importance of having a strong syndicate that is willing to keep learning as the opportunity develops. You have to keep turning over cards, talking continuously with experts and key opinion leaders, and reassessing what the data and the market are telling you.

That is especially important in early-stage drug development because the treatment landscape can change while you are still advancing a program. In ADHD, for example, other medicines were approved along the way, including new stimulant formulations such as extended-release Adderall. When the standard of care changes during development, you have to be prepared to adjust your strategy around it.

You have to maintain conviction in the underlying science while also being willing to adapt. In the case of centanafadine, the continued need for additional ADHD treatment options, particularly non-stimulant options with lower abuse potential, remained very clear.

You were involved from the early stages of the opportunity through building the syndicate and supporting the company. Where do you think you and Clarevia made the greatest difference in helping Neurovance reach the point where Otsuka could take the program forward?

PW: A big part of our role was working with the other investors to build a strong syndicate and taking an active role at the board level. As the program moved from a research project into a development-stage company, that meant helping recruit the right management team and making sure there was both the leadership and the financial commitment needed to keep advancing the program.

For a firm like Clarevia, strength of syndicate is especially important in therapeutic investments. Our goal was to help de-risk the program to the point where it was ready for the next stage of development and attractive to a partner with the resources to take it further.

My own background is in manufacturing and what I sometimes call the less glamorous parts of drug development. I was able to advocate for chemistry, manufacturing and controls, or CMC, to advance in parallel with the clinical program. Making sure the drug can actually be manufactured and formulated appropriately is a critical part of getting a program ready for later-stage development.

Centanafadine is now an FDA-approved medicine on its way to patients. After following the molecule from such an early stage, what does it mean to finally see it become a treatment people can actually receive?

PW: It’s incredibly satisfying and gratifying. I’ve seen firsthand how significant the need can be, particularly for children with ADHD, and how meaningful it is to have an effective treatment option that is not a traditional stimulant.

Stimulants can be very effective, but they also come with risks, including the potential for abuse and dependence. Seeing a non-stimulant option reach patients after following this program from such an early stage is hugely rewarding.

What makes it especially meaningful is knowing that this is no longer just a promising molecule or a clinical program. It is now an approved medicine that physicians can prescribe and patients can actually receive.