Crick Spin-Out ALTx to Target Cancer Cell Immortality

The London biotech will develop small-molecule therapies to target a pathway some cancer cells use to lengthen their life.

Published on Feb. 11, 2026

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Founded in late 2024, ALTx Therapeutics has come out of stealth mode with plans to develop therapies to target the alternative lengthening of telomeres (ALT) pathway in cancer cells. The company, which spun out of the Francis Crick Institute, is working to find genetic targets that can disrupt the ALT process and promote cancer cell death in aggressive cancers like osteosarcoma and neuroblastoma.

Why it matters

Targeting the ALT pathway is a fairly new approach in cancer therapeutics, as many cancers typically reactivate an enzyme called telomerase to increase the age of tumor cells. However, 10-15% of cancers use the ALT method instead, which allows telomeres to copy information from other telomeres to maintain their length and allow excessive cell division. Cancers that use the ALT method tend to be very aggressive and have a poor prognosis, so new therapeutic opportunities in this area are critical.

The details

ALTx Therapeutics is working in collaboration with the Crick's chemical biology team to help identify potential drug candidates to progress to clinical trials. The company currently has three programs that are all structurally enabled, and they are doing target engagement evaluation and lead optimization for one of them, as well as preclinical toxicology evaluation.

  • ALTx Therapeutics was founded in late 2024.
  • The Francis Crick Institute, where the company is currently based, opened 10 years ago.

The players

ALTx Therapeutics

A London biotech company that has spun out of the Francis Crick Institute with plans to develop therapies to target the alternative lengthening of telomeres (ALT) pathway in cancer cells.

Simon Boulton

The founder and chief scientific officer of ALTx Therapeutics, as well as a principal group leader at the Francis Crick Institute, where he has been researching telomeres and DNA repair in cancer for more than 2 decades.

Joanna Redmond

The leader of the Crick's chemical biology team, which is collaborating with ALTx Therapeutics to help identify potential drug candidates.

Syncona

A UK-based life sciences investment company that has provided £12.55 million ($17.1 million) in funding to help ALTx Therapeutics move toward the clinic.

Cancer Research Horizons

The innovation arm of nonprofit Cancer Research UK, which has also provided funding to ALTx Therapeutics.

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What they’re saying

“We've got three programs that are all structurally enabled. We obviously are doing target engagement evaluation, and we're doing lead optimization for one of them. We're also doing a lot of preclinical toxicology evaluation.”

— Simon Boulton, Founder and Chief Scientific Officer, ALTx Therapeutics

“ALT ends up being used in many cancers that have a very poor prognosis. They tend to be very aggressive, and currently there's no real therapeutic opportunity.”

— Simon Boulton, Founder and Chief Scientific Officer, ALTx Therapeutics

What’s next

ALTx Therapeutics is working to progress its lead drug candidate through preclinical toxicology evaluation, with the goal of moving it into clinical trials.

The takeaway

Targeting the alternative lengthening of telomeres (ALT) pathway in cancer cells represents a promising new approach to treating aggressive and hard-to-treat cancers, and the work being done by ALTx Therapeutics could lead to much-needed new therapeutic options for patients.