

Rallybio is handing 97% of its company to a private oncology startup, and some of biotech's biggest investors just piled $215 million into the deal. Here's why a reverse merger with Avenzo Therapeutics might be the most interesting deal structure in biotech this year.
In December 2025, you could buy a share of Rallybio for 75 cents. The rare-disease biotech was bleeding cash, its pipeline was stalling, and Wall Street had essentially stopped paying attention. The stock had cratered 87% from its IPO price, and the company's market cap barely cleared $30 million.
Fast forward to this week: Rallybio just agreed to hand over its Nasdaq listing, its corporate identity, and virtually all of its equity to a private oncology company called Avenzo Therapeutics. In return, Rallybio's shareholders get a 2.8% sliver of the combined company plus some contingent value rights (CVRs) tied to whatever becomes of the old rare-disease assets.
That might sound like a terrible deal. But Rallybio's stock has already ripped from $2.16 to the mid-teens this year, and a murderer's row of investors just poured $215 million into the deal. So what's actually going on here?
Think of Rallybio as a house with great bones (a Nasdaq listing, some cash, clean SEC filings) but a crumbling interior (failed pipeline, no revenue, shrinking team). Avenzo is the buyer with big renovation plans and deep pockets.
The technical term is a reverse merger: Avenzo merges into Rallybio, becomes the surviving operating company, and takes over everything. The combined entity will be renamed Avenzo Therapeutics, trade under the ticker AVZO, and focus entirely on cancer drugs. Rallybio's rare-disease programs? Stuffed into CVR structures so former shareholders can collect if those assets ever get sold or partnered.
This playbook has become surprisingly popular in biotech lately. When the IPO window is only cracked open for big, late-stage stories, private companies with promising early data are finding it faster and cheaper to merge into a struggling public shell than to go through a traditional offering. It's like using the carpool lane instead of sitting in IPO traffic.
Historical precedent is encouraging, too. and both started as reverse mergers. J&J eventually bought one, Pfizer bought the other. Not every shell deal works out that well, but the ceiling is real.

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Avenzo was founded in August 2022 by Athena Countouriotis, M.D. and Mohammad Hirmand, M.D., both former leaders at Turning Point Therapeutics. If that name rings a bell, it should: Bristol Myers Squibb acquired Turning Point for $4.1 billion. These founders have done this before.
Before the Rallybio deal was even announced, Avenzo had already raised a staggering $446 million across seed, Series A/A-1, and Series B rounds. The investor list reads like a who's who of healthcare finance: OrbiMed, Foresite Capital, SR One, NEA, Deep Track Capital, Lilly Asia Ventures, Sofinnova, and Sands Capital, among others.
The pipeline is built around four clinical-stage oncology programs, all in Phase 1 or Phase 1/2 trials targeting solid tumors:
All four programs are early. None have pivotal data yet. But the targets are validated, the science is trendy (CDK inhibitors and ADCs are two of oncology's hottest categories right now), and the founding team has a track record of building exactly this kind of portfolio and selling it to Big Pharma.
The $215 million concurrent private placement is arguably the most important part of this deal. It was oversubscribed, which means investors wanted in so badly that demand exceeded the available allocation. The placement was run by Leerink Partners, Goldman Sachs, Piper Sandler, and Guggenheim Securities, and the investor list includes Blackstone, T. Rowe Price, Vivo Capital, OrbiMed, NEA, and Foresite Capital.
That's not speculative retail money. Those are sophisticated, long-term healthcare investors writing large checks. When Blackstone and T. Rowe show up in a biotech PIPE (private investment in public equity), it signals institutional conviction.
Combined with cash at closing, the financing is expected to fund operations into late 2028. That's enough runway to generate Phase 1 data across all four programs and start several Phase 2 studies. In biotech, having two-plus years of cash is the difference between negotiating from strength and negotiating from desperation.
Let's be honest: if you bought Rallybio for its rare-disease pipeline, this deal is a funeral with a consolation prize. Legacy shareholders end up with roughly 2.8% of the combined company on a fully diluted basis. Avenzo's equityholders and the new financing investors take the other 97.2%.
But there are a few sweeteners. Rallybio plans to distribute most of its remaining cash to existing shareholders before the deal closes. And those CVRs could pay out if proceeds are generated from the previously disclosed sale of the ex-US interest in the RLYB212 FNAIT program or any potential monetization of other legacy assets. It's a long shot, but it's not zero.
The break fees tell you who has the leverage here: if Avenzo walks, it owes $20 million. If Rallybio walks, it owes just $600,000. That asymmetry speaks volumes about which side of this deal holds the cards.
Rallybio-Avenzo is a textbook example of a trend reshaping small-cap biotech. Dozens of public companies are trading at or below their net cash value right now, with investors having lost faith in their pipelines. Meanwhile, well-funded private biotechs need public listings but don't want to risk an uncertain IPO.
The result? A wave of "combine to survive" mergers where the private company gets a clean public vehicle and the public company's shareholders get a small piece of something potentially much bigger. Recent deals like Kalaris-AlloVir have followed a similar playbook.
The combined Avenzo Therapeutics will be led by Countouriotis as CEO and Chair and Hirmand as CMO, with a seven-member board. The deal is expected to close in Q4 2026.
From sub-dollar stock to oncology platform in under a year: that's the Rallybio story now. Whether it's a success story or a cautionary tale depends entirely on what happens in Avenzo's clinics over the next two years. Four Phase 1 programs, $215 million in fresh capital, and a founding team that already sold one company for $4.1 billion.
The ingredients are there. Now comes the cooking.
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