SEPTInvestingStart Free

RLYB 424B3: Acquisition

Rallybio Corporation and Avenzo Therapeutics have

Filed with the SEC on · accession 0001193125-26-422924

RLYB filed a 424B3 (prospectus (offering)) with the SEC on Oct 15, 2026. Rallybio Corporation and Avenzo Therapeutics have entered into a merger agreement whereby Avenzo will merge into a wholly owned subsidiary of Rallybio, with Rallybio changing its name to Avenzo Therapeutics. The stock moved -0.8% by the first close after the filing.

Summary of the filing

Rallybio Corporation and Avenzo Therapeutics have entered into a merger agreement whereby Avenzo will merge into a wholly owned subsidiary of Rallybio, with Rallybio changing its name to Avenzo Therapeutics. The combined company will be majority-owned by Avenzo's pre-merger equityholders (approximately 56.6%), with Rallybio's existing stockholders retaining only about 2.8% and concurrent financing investors owning about 40.6%.

For details, click here →How to read a 424B3 →

Key details

Aggregate purchase price for Concurrent Financing$215.0M
Rallybio Net Cash as of August 15, 2026$82.2M
Fixed valuation for Avenzo in merger$300.0M
Valuation for Rallybio in merger$15.0M
Acquirer (reverse merger target; will change name to avenzo therapeutics)Rallybio Corporation
Target (will survive as wholly owned subsidiary of rallybio)Avenzo Therapeutics, Inc.
Merger subsidiary of rallybioFarmington Merger Sub, Inc.

How RLYB stock reacted

Close before

$16.91

Oct 14, 2026

First close after

-0.77%

$16.77

5 trading days

-4.05%

$16.22

Since filing

-6.83%

$15.75

✦ Ask GOAX AI about this filing — what it means for RLYB, what changed since its last filings and what to watch next.

Try it free for 7 days

🔔 Want to stay updated on new SEC filings for RLYB?

Click here

Frequently asked questions

What did RLYB file with the SEC on Oct 15, 2026?

RLYB filed a 424B3 (Acquisition). Rallybio Corporation and Avenzo Therapeutics have entered into a merger agreement whereby Avenzo will merge into a wholly owned subsidiary of Rallybio, with Rallybio changing its name to Avenzo Therapeutics. The combined company will be majority-owned by Avenzo's pre-merger equityholders (approximately 56.6%), with Rallybio's existing stockholders retaining only about 2.8% and concurrent financing investors owning about 40.6%.

What does a acquisition mean for RLYB stock?

A contract important enough that investors need to know about it — a big customer contract, a loan, a merger agreement or a partnership.

How do I read a 424B3?

The final terms of an offering of shares or bonds. Look at price, number of shares and the discount to the market price. Large offerings dilute existing shareholders.

Why are SEC filings important?

Public companies must tell the SEC about anything that can change their value — results, leadership changes, big deals, new shares, bankruptcy. Filings are the official source, often before the news. A 424B3 (prospectus (offering)): The final terms of an offering of shares or bonds.

How did RLYB stock react to this filing?

RLYB closed at $16.91 before the filing and $16.77 on Oct 15, 2026 (-0.77%). Five trading days later: $16.22 (-4.05%).

Other RLYB SEC filings

Get alerts when RLYB files with the SEC, plus live charts, key levels and news for 13,000+ stocks.

Try SEPT free for 7 days
RLYB overviewRLYB analysisRLYB newsLatest SEC filings