In drug development, patients are the people a therapy is for. They enroll, they wait, they hope. What they almost never do is own a stake in the company racing to treat them.

Yael Weiss built Mahzi Therapeutics to break that rule. Her clinical-stage biotech develops gene therapies for rare neurodevelopmental disorders , and it is now dosing patients in the first-ever gene therapy trial for Pitt Hopkins syndrome.

Alongside that milestone, Mahzi launched a Regulation Crowdfunding round, allowing families affected by these diseases to invest in the treatments. Others have done this, too.

Half the early reservations came from parents of rare-disease children. "They come in as investors," Weiss notes, "and if the drug is successful, they will see a return on their investment." The experiment underway at Mahzi is whether the people a therapy is for can also fund, design, and own it.

They Come In As Investors, Not Philanthropists

For most of biotech, "patient-centric" is a value, not a financial structure. Companies thank advocacy groups, put a parent on an advisory board, and move on. Mahzi wrote patients into the capitalization table instead.

The mechanism is deliberate. Advocacy groups that funded early academic research on a disorder can invest in the Mahzi program built from that work, rather than donate to it. "The Mahzi model allows...advocacy groups to invest in their program," Weiss explains. Those who can't contribute still see their science advanced; those who can share in the upside.

Mahzi is not doing this from a position of weakness. The company has raised $60 million from Venrock, HealthCap, Droia Ventures, and HBM Partners, plus $8 million in non-dilutive grant awards from the California Institute for Regenerative Medicine. The Werunder Reg CF community round extends that cap table to ordinary families at a $250 minimum, a door that traditional venture financing keeps shut.

"It also gives people a chance to participate in something that they don't normally get to do because VCs write very large checks," Weiss points out. For the families involved, the shift from bystander to shareholder is not symbolic. It is a claim on the outcome.

Audrey Davidow, president and CEO of the Pitt Hopkins Research Foundation, describes what that partnership feels like from the community side. "Mahzi Therapeutics doesn't just talk about change—they make it happen. They care about our children as if they were their own," she says.

Why She Went Around Venture Capital

The ownership model is also a response to a market that has never funded companies like Mahzi generously. In 2023, only 2% of all seed and Series A biotech dollars went to rare disease companies , and the bar is even higher for a first-time woman founder building in a category most investors have never heard of.

Weiss is candid that raising in 2025 looks nothing like raising during the pandemic, when capital flowed freely, and pitches happened over Zoom. Her strategy was never to canvass hundreds of funds, but to find the few investors for whom the mission lands personally. Her lead investor has a rare disease and a son with autism. Another had made money in a rare disease before. A third runs a fund dedicated to it.

So rather than knock on more venture doors for her next raise, Weiss turned to the community she already works with. Mahzi is raising a $10 million bridge round on its Series A terms to reach clinical data. It chose Reg CF to get partway there. She describes the logic as "creative sources of funding that we could leverage now, instead of knocking on venture doors.” The early reservations proved the thesis, she says: 50% of the people who made reservations are parents.

That intersection of community and capital is exactly what specialists in the space have started to bet on. "We are really, really excited about community rounds and this intersection of community and capital," argues Maria Springer , founder and CEO of Capital Department, the firm running Mahzi's raise.

Institutional backers see the timing as the draw. "It is a unique privilege to work with them and to be able to invest alongside such a renowned syndicate at a crucial stage when the company is right on the cusp of clinical data," observes Shalini Sharp, a biotech and nonprofit board member and strategic advisor.

How Patients Design The Drug

If patients are going to own part of the company, it helps that they also help build the product. Mahzi treats patient input as engineering input rather than sentiment.

The Disease Concept Model

For each disorder, most of which have never been studied in a clinical trial, Mahzi constructs what Weiss calls a disease concept model. One of her first hires was a pediatric psychologist whose expertise is designing endpoints. The team interviews families in depth before writing the trial, and what parents want often surprises outsiders.

"We're not making assumptions that if there are seizures, the seizures are the key things that the parent wants to see changed," Weiss says. "Actually, most of the parents want their child to say a few words." Those answers become the endpoints that the trial measures.

Because there is no roadmap for these diseases, Mahzi runs its natural history study in parallel with the trial rather than before it. "You have to hit the road running. You can't do things sequentially," Weiss adds, because families are waiting, and the science suggests earlier treatment works better.

The Science Behind The Bet

The clinical gamble rests on preclinical results. In animal models of Pitt Hopkins syndrome, Mahzi's gene therapy restored neuronal structure toward neurotypical levels, the kind of de-risking that made a first-in-human trial credible (). Its lead candidate, MZ-1866, delivers a functional copy of the TCF4 gene, the mutation that causes the disorder, using an AAV9 vector.

Why The Ceiling Is The Point

Weiss rejects the idea that big pharma is simply getting rare diseases wrong. Economics is the answer. "A pharma company will always choose a blockbuster over a small patient population," she contends, and a therapy for 8,000 people worldwide will never compete internally with a multibillion-dollar franchise.

That ceiling is precisely Mahzi's opening. A lean company can commercialize a $200 million to $300 million product that a large one can't justify. Mahzi estimates its approach could address more than 800 rare neurogenetic disorders within a $16 billion-plus market. "We can do that where no one else is willing to do it," Weiss emphasizes.

What Success Looks Like In Five Years

Pressed for a concrete outcome rather than a mission statement, Weiss keeps it plain. Success means "that we are able to successfully treat patients with neurodevelopmental disorders and as many disorders as we can, leveraging our size and our resources."

The second half of her answer is the one that reveals the model. Success also means "forming more bonds with patient advocacy groups and helping them advance their science."

That is the wager Mahzi is really making. Not just that a small company can treat diseases the industry has written off, but that the families it treats can be partners in the science, owners of the company, and beneficiaries of the outcome all at once. The old rule said patients receive value. Weiss is testing whether they can hold it.