As of Sunday, December 21, 2025, Amicus Therapeutics, Inc. (NASDAQ: FOLD) has effectively shifted from a “biotech story stock” to a deal-driven stock. The reason is simple and decisive: BioMarin Pharmaceutical (NASDAQ: BMRN) agreed to acquire Amicus in an all-cash transaction priced at $14.50 per share, putting a hard cap on the near-term upside—unless a competing bid emerges. SEC+1
With U.S. markets closed for the weekend, the most recent close available is $14.18 (Dec. 19, 2025)—a roughly 30% one-day jump that pushed shares close to the deal price and turned the remaining gap into a classic merger-arbitrage spread.
Below is what’s driving Amicus stock now, what the latest forecasts imply, and what investors will be watching next.
What happened to Amicus Therapeutics stock?
BioMarin is buying Amicus for $14.50 per share in cash
On December 19, 2025, BioMarin and Amicus announced a definitive agreement under which BioMarin will acquire Amicus for $14.50 per share in an all-cash transaction, valuing Amicus at approximately $4.8 billion (equity value). The boards of both companies approved the deal, and Amicus’ board recommended that shareholders vote in favor.
Expected closing window: Q2 2026 (with a “long-stop” date)
The companies say the transaction is expected to close in Q2 2026, subject to customary conditions including regulatory clearances and Amicus shareholder approval.
The merger agreement also includes a key detail merger-arb traders care about: an “End Date” of June 19, 2026, after which either party can terminate if the deal hasn’t closed—with potential automatic extensions under certain conditions (notably around antitrust-related clearances). SEC
How the deal is financed
BioMarin says the transaction is not subject to financing conditions and will be financed through a combination of cash on hand and ~$3.7 billion of non-convertible debt financing (with Morgan Stanley Senior Funding providing a bridge commitment).
Why FOLD jumped—and why it’s now trading like a “deal stock”
Amicus closed at $14.18 on Dec. 19, reflecting the market rapidly repricing FOLD toward the $14.50 cash consideration.
That leaves about $0.32 per share of spread to the offer price (roughly 2%). In plain English: from here, FOLD’s day-to-day movement is less about quarterly execution and more about the market’s running estimate of:
- Probability the deal closes
- How long it takes
- Whether any surprise conditions (or delays) show up
- The odds of a higher competing bid
This is why takeover targets often trade slightly below the offer: markets price in time value + risk. No magic—just finance being finance.
A big “de-risking” detail: Galafold patent litigation was resolved
One underappreciated part of the announcement is that Amicus resolved pending U.S. patent litigation over Galafold tied to generic challenges.
According to the companies’ disclosed terms, Amicus entered license agreements with Aurobindo and Lupin that would allow U.S. generic entry beginning January 30, 2037 (if approved by the FDA and absent certain customary exceptions), and the related Hatch-Waxman litigation would be terminated.
BioMarin explicitly linked this to expected U.S. exclusivity, stating that—based on these settlements—U.S. exclusivity for Galafold is expected through January 2037.
Why this matters for the stock: IP uncertainty is valuation poison for rare-disease commercial assets. Clearing that overhang improves visibility on future cash flows, which can make an acquisition easier to justify—and easier to finance.
What BioMarin is really buying: two marketed rare-disease drugs plus pipeline optionality
BioMarin is acquiring a revenue base that—unlike many biotech acquisitions—is not purely “promise.” Amicus brings:
- Galafold (migalastat) for Fabry disease
- Pombiliti (cipaglucosidase alfa-atga) + Opfolda (miglustat) for Pompe disease
- U.S. rights to DMX-200, a Phase 3 asset for FSGS (rare kidney disease)
Recent commercial performance: the numbers behind the story
In Amicus’ Q3 2025 update (quarter ended Sept. 30, 2025), the company reported:
- Total revenue: $169.1M for Q3 2025
- GAAP net income: $17.3M for Q3 2025
- Cash, cash equivalents, and marketable securities: $263.8M at Sept. 30, 2025
Product revenue breakdown in Q3 2025:
- Galafold:$138.3M
- Pombiliti + Opfolda:$30.7M
That commercial momentum is exactly what makes Amicus different from the average “pre-revenue biotech” M&A target.
Company guidance and longer-term outlook (pre-deal)
Amicus’ 2025 guidance (reiterated in Q3 2025 materials) included:
- Total revenue growth:15% to 22%
- Galafold revenue growth:10% to 15%
- Pombiliti + Opfolda revenue growth:50% to 65%
- Gross margin: “mid 80%”
- Expectation of positive GAAP net income during H2 2025
Amicus also said it anticipated surpassing $1 billion in total sales in 2028—a forward-looking statement that, if achieved, would have materially changed the company’s standalone valuation path.
The “third leg” of the deal: DMX-200 and a fresh Phase 3 milestone
A lot of the weekend commentary has focused on the two marketed drugs—and fair enough. But BioMarin is also picking up U.S. rights to DMX-200, which Amicus licensed earlier in 2025.
And crucially, there’s a timely development: on December 15, 2025, Dimerix (the trial sponsor) announced that the ACTION3 Phase 3 trial completed recruitment, having recruited and dosed its target 286th adult patient. The release also noted:
- 69 adult patients have already completed the full two-year treatment period
- 94% uptake into an open-label extension among completers (65 of 69)
- Seven scheduled Independent Data Monitoring Committee reviews had been completed with no protocol changes or safety concerns identified
- Dimerix and Amicus intend to seek FDA feedback on proposed endpoints prior to blinded analysis
For FOLD shareholders, DMX-200 is now part of what BioMarin is paying for—though the economics of that optionality will ultimately depend on how BioMarin prioritizes development post-close.
What analysts and industry outlets are saying about the deal
The deal has been broadly framed as a strategic fit: BioMarin has scale in rare disease commercialization and manufacturing, while Amicus brings marketed assets with growth trajectories and clearer IP footing after the Galafold settlements.
- Reuters highlighted the acquisition rationale and financing mix, and noted the market reaction (Amicus up ~30% on the news).
- Fierce Pharma described the transaction as BioMarin’s largest ever and emphasized the commercial growth opportunity—citing leadership commentary that each of Galafold and Pombiliti/Opfolda could have $1B peak sales potential and pointing to global expansion opportunities given BioMarin’s footprint.
- BioPharma Dive noted the deal should close between April and June 2026, and it summarized the revenue contribution of Amicus’ marketed therapies while also calling out the Galafold litigation resolution.
Key deal terms that matter for FOLD shareholders
How you get paid
Per the merger agreement, eligible Amicus shares will be converted into the right to receive $14.50 per share in cash (subject to withholding taxes, and excluding certain categories like dissenting shares).
Break fee: $175 million
If Amicus terminates the agreement in certain scenarios involving a superior proposal (or related conditions described in the merger agreement), the company may owe BioMarin a termination fee of $175,000,000.
This matters because it can discourage casual interlopers and shapes how realistic a topping bid is—especially if a new bidder would need to offer enough incremental value to compensate for both the higher price and any deal-friction costs.
What could move Amicus stock next?
Between now and closing, the biggest price drivers are likely to be deal mechanics, not product updates:
- Proxy filing + shareholder vote timing
- Regulatory review progress (including HSR/antitrust processes)
- Debt market conditions as BioMarin finalizes permanent financing (even though the deal isn’t financing-contingent)
- Any competing-bid headlines (unlikely to be frequent, but always the wildcard in cash deals)
- Sector-wide risk sentiment—because even “deal stocks” can wobble when markets get stressed
Bottom line on Dec. 21, 2025
Right now, Amicus Therapeutics stock is being priced primarily as a probability-weighted claim on $14.50 in cash. The fundamentals—growing rare-disease revenues, a clearer Galafold U.S. exclusivity runway into 2037, and Phase 3 progress on DMX-200—help explain why BioMarin was willing to pay a premium and why the market largely accepted the new valuation quickly.
From this point forward, the “forecast” most traders will implicitly make isn’t a 12‑month price target—it’s a simpler (and more brutal) pair of questions:
- Does the deal close?
- When does it close?
