Mammoth Biosciences
Biotech building CRISPR gene-editing therapies from proprietary microbial enzymes.
On the record
Checkpoint: MB-111 IND filing and first patient dosed for FCS/SHTG
The call
Mammoth's fate rests on whether MB-111 reaches the clinic in 2026 before Intellia's lead and its own cash runway close in.
Mammoth Biosciences makes ultra-small CRISPR tools, a type of molecular scissors used to edit genes inside living patients. The company has backing from Regeneron and smart science from Nobel Prize winner Jennifer Doudna, but its main drug candidate has never been tested in humans yet. A rival company called Intellia already got approval to test their CRISPR therapy in patients in early 2026, putting Mammoth years behind schedule. The company laid off workers in 2025 and its valuation may have dropped, which signals trouble. What matters now is whether Mammoth can get its lead drug into human testing soon and whether it can raise new money without giving up more company value.
Why
01
AI pressure: AI protein-design tools like AlphaFold and Isomorphic Labs. AI models can now predict novel enzyme structures, narrowing Mammoth's metagenomic discovery edge over time. Could AI do the core job? Unlikely.
02
Bigger players: Intellia Therapeutics. Intellia cleared Phase 3 for an in vivo CRISPR therapy in April 2026, putting Mammoth years behind in the clinic. Could a giant copy it? Probably.
03
What protects it. Patented ultracompact CRISPR enzymes and a Regeneron deal worth up to $370M per target give it IP and cash cover.
What would change this call
Mammoth files an IND and doses first patient with MB-111 in 2026. Shows Mammoth can convert its CRISPR platform into a real clinical asset, not just IP.
Confirmation or denial of the rumored $1.35B Series D-3 round from December 2025. Reveals whether investors still value Mammoth above its 2021 mark or below it.
Announcement of a second or third layoff round following the May 2025 cuts. Would indicate cash strain and shrinking runway ahead of clinical proof.
Confirmation or denial of the rumored $1.35B Series D-3 round from December 2025. Reveals whether investors still value Mammoth above its 2021 mark or below it.
Announcement of a second or third layoff round following the May 2025 cuts. Would indicate cash strain and shrinking runway ahead of clinical proof.
Key numbers
- Regeneron paid $95M equity plus $100M upfront, 2024
- 24 employees laid off in restructuring
- MB-111 named first development candidate
Named risks
- Lead asset MB-111 remained preclinical as of mid-2026, with no human dosing yet.
- Intellia's April 2026 Phase 3 win puts Mammoth years behind the leading in vivo CRISPR competitor.
- No confirmed new funding round since the $1B September 2021 valuation, raising down-round risk.
- May 2025 layoffs of 24 staff signal organizational contraction amid strategic realignment.
- AI-driven protein design tools could compress Mammoth's historical metagenomic discovery advantage.
Rivals, as read in July 2026
| Rival | Direction | Evidence |
|---|---|---|
| Intellia Therapeutics | losing to | Intellia cleared Phase 3 for lonvo-z in April 2026, first in vivo CRISPR success, while MB-111 stayed preclinical |
| CRISPR Therapeutics/Vertex | losing to | Their Casgevy is the only FDA-approved CRISPR medicine (ex vivo), Mammoth has no approved product |
| Metagenomi Therapeutics | contesting | Peer also mining metagenomic libraries for novel CRISPR enzymes, per PitchBook competitor mapping |
| Scribe Therapeutics and Arbor Biotechnologies | contesting | Both spun from Doudna-lab science, engineering compact Cas enzymes as of 2026 |
| Regeneron (as multi-platform hedger) | contesting | Regeneron partners with both Mammoth (2024) and Intellia, hedging capital across in vivo CRISPR platforms |
Questions people ask
- Is Mammoth Biosciences profitable in 2026?
- No. Mammoth is a private, pre-commercial biotech with no approved products. Its income comes from partnership upfronts and milestones, such as Regeneron's April 2024 deal worth $95M equity plus $100M upfront and up to $370M per target in milestones, not product sales.
- Has Mammoth Biosciences had layoffs?
- Yes. Mammoth cut 24 staff in May 2025 as part of a 'strategic alignment,' confirmed by CEO Trevor Martin to Fierce Biotech, occurring alongside its pivot to focus resources on lead candidate MB-111.
- Is Intellia Therapeutics beating Mammoth Biosciences to market?
- Yes, significantly. Intellia reported positive Phase 3 topline results for lonvo-z in hereditary angioedema in April 2026, the first Phase 3 success for an in vivo CRISPR therapy, while Mammoth's lead asset MB-111 remained preclinical as of mid-2026.
- Could AI replace Mammoth Biosciences' CRISPR discovery work?
- Not entirely. AI can speed up enzyme discovery and off-target prediction, but Mammoth's patented ultracompact CRISPR enzymes (CasPhi, Cas14) come from proprietary metagenomic wet-lab sample libraries and require FDA clinical trials that AI cannot substitute for.
- What is Mammoth Biosciences worth?
- Its last confirmed valuation was about $1B, set in September 2021 after a $195M raise led by Redmile Group. A December 2025 report of a $1.35B Series D-3 round exists only via a data aggregator and is unconfirmed by any company press release.
- Who backs Mammoth Biosciences?
- Mammoth is privately held, backed by investors including Redmile Group, Foresite Capital, Senator Investment Group, Sixth Street, Mayfield Fund, 8VC, and corporate partner Regeneron Pharmaceuticals, which took a $95M equity stake in April 2024.
Timeline
- 2026-06-25Mammoth signs MOU with Abu Dhabi's M42/DoH on gene-editing manufacturing and clinical research
- 2026-05-11Rival Intellia reports positive Phase 3 results for in vivo CRISPR therapy lonvo-z
- 2025-10-01Mammoth presents preclinical MB-111 data at ESGCT congress
- 2025-05-05Mammoth nominates MB-111 as first development candidate, targeting FCS and SHTG
- 2025-05-05Mammoth lays off 24 staff in strategic alignment, confirmed by CEO Trevor Martin
- 2024-04-25Regeneron invests $95M equity, $100M upfront in CRISPR gene-editing collaboration with Mammoth
- 2023Mammoth pivots from CRISPR diagnostics to in vivo therapeutics
- 2022Mammoth partners with Bayer on ultra-small CRISPR systems
- 2021-09-09Mammoth raises $195M, reaching roughly $1B valuation, led by Redmile Group
- 2017Mammoth Biosciences founded by Jennifer Doudna, Trevor Martin, Janice Chen, Lucas Harrington
Revision history
29 July 2026
First assessed. Losing its protection. The text above is fixed as of this date and is not edited afterwards.
In the same band
Sources
- Mammoth Biosciences (2025-12-02)
- Mammoth Biosciences Raises $195 Million... (2021-09-09)
- Regeneron and Mammoth Biosciences Collaborate... (2024-04-25)
- Mammoth Biosciences (2026-01-09)
- Mammoth Biosciences IPO Timeline and Financing Details (2023-11-14)
- Mammoth Biosciences Revenue 2022 (2025-11-23)
- Mammoth Biosciences Announces Nomination of MB-111... (2025-05-05)
- Mammoth Biosciences to Present Preclinical Data on MB-111... (2025-10-01)
- Unity and Mammoth embark on restructurings, prompting layoffs (2025-05-05)
- Mammoth Biosciences (2026-06-30)
- Mammoth Biosciences 2026 Company Profile
- Mammoth Biosciences (2024-04-23)