Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on the day's biggest business stories

Subscribe to Axios Closer for insights into the day’s business news and trends and why they matter

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Stay on top of the latest market trends

Subscribe to Axios Markets for the latest market trends and economic insights. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sports news worthy of your time

Binge on the stats and stories that drive the sports world with Axios Sports. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tech news worthy of your time

Get our smart take on technology from the Valley and D.C. with Axios Login. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Get the inside stories

Get an insider's guide to the new White House with Axios Sneak Peek. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Denver news?

Get a daily digest of the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Des Moines news?

Get a daily digest of the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Twin Cities news?

Get a daily digest of the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Tampa Bay news?

Get a daily digest of the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Charlotte news?

Get a daily digest of the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Illustration: Sarah Grillo/Axios

A gene editing tool with promising clinical applications is facing renewed scrutiny after several recent studies found its side effects could be worse than expected.

Sometimes heralded as "revolutionary," CRISPR-Cas9 is the subject of a massive investment of money and research efforts toward the ultimate goal of editing human genes, which many hope will begin on a trial basis in the U.S. this year.

The big question: Is CRISPR-Cas9 safe enough to expand it into human clinical trials? The consensus of scientists whom Axios spoke with: Not quite yet.

"The CRISPR reagents are wonderful tools for research but we still do not control them enough for safe and efficient use into patients. Particularly we know very little about the DNA repairing mechanisms triggered after the cut by Cas9."
— Lluis Montoliu, research scientist, Spanish National Research Council (CSIS)

CRISPR is a hot topic, and for good reason: it could have a wide range of applications for treating diseases and correcting genetic conditions in humans.

What's happening: Yesterday Science Translational Medicine published a study in which researchers took cancer cells that had left their original tumor in mice, edited them with CRISPR to have "suicide genes," and re-injected them into the animal to see if they would return to the tumor and end up killing the cancer. They found "marked survival benefits."

  • NIH Director Francis Collins told STAT in an early May interview:
"I’m very excited about the potential of gene-editing to cure rare diseases for which we know the molecular defect and there’s no current therapy."

Research money is flowing into large and small companies aiming to be on top of the market. Axios' Bob Herman provided the chart below for a quick peek at three companies focused on CRISPR research.

Funding that three of the top CRISPR companies have raised since they were founded. Data from Crunchbase on July 18.

Still, there's always been a steady drumbeat of cautionary tales since it's been known the editing process often targets the wrong gene. Problems can also be caused when the cell repairs itself after the editing process, Montoliu says.

This was brought sharply into focus in recent studies:

  • Earlier this week, U.K. scientists published a study in Nature Biotechnology saying in some cases CRISPR may cause large deletions and rearrange the DNA it is targeting. They warned that the problem has been "seriously underestimated."
  • This follows recent studies that found CRISPR may inadvertently increase the risk of triggering cancer.
  • In May, the FDA halted a trial for sickle cell patients before it started. Scientists planned to edit bone marrow stem cells using CRISPR and then transplant them back into the patients.

There are other CRISPR programs, though, that may be less prone to errors, such as base editing that allows for one or a few specific base DNA pairs to be altered without the creation of a double-strand break, which is often when the cell repair function creates errors. 

Shondra Pruett-Miller, director of the Center for Advanced Genome Engineering at St. Jude Children’s Research Hospital, says base editing is relatively new and is limited to small modifications, but it shows promise. "The ability to make genome edits without creating potentially dangerous DNA double-strand breaks is a great idea and could potentially have reduced risks," she says.

What's next: Patrick Hsu, a principal investigator and Salk Helmsley fellow at the Salk Institute for Biological Studies, says there should be standardized protocols and data analysis pipelines for the field.

Michael Kosicki, study author of the Wellcome Sanger Institute study from the U.K., agrees more analysis is needed before clinical trials can proceed, even with base editing. He says:

"Some questions that need to be asked when attempting 'regular DSB' CRISPR therapy are: Is there any important genes close to the one we want to edit? How often do large deletions, rearrangements and especially translocations happen in relevant cells? And finally, how much risk is acceptable? The answer to the last question depends on how serious the treated disease is."

Still, there remains hope for the future use of CRISPR in humans. Once it's proven safe and effective, Pruett-Miller says children could especially benefit from CRISPR-Cas9 therapy.

"CRISPR-Cas9 therapies are especially exciting because they are not limited to one disease and have the potential to correct disease-causing mutations at the source (the genomic DNA).  The hope is that if we can correct these genomic mutations early in life, we could prevent the devastating effects associated with a lifetime of accumulating damage, which often results in shortened lifespans."
— Shondra Pruett-Miller

Go deeper

Dan Primack, author of Pro Rata
20 mins ago - Economy & Business

Private equity's other tax fight

Illustration: Rae Cook/Axios

Private equity is carefully watching the D.C. debate on corporate taxes, in which Senate Democrats seem to be settling on a 25% rate.

Zoom in: Marginal rates obviously matter, but for PE it's just an appetizer before the weedier work begins on issues like corporate interest deductibility.

Making sense of Biden's big emissions promise

Illustration: Sarah Grillo/Axios

President Biden's new U.S. emissions-cutting target is a sign of White House ambition and a number that distills the tough political and policy maneuvers needed to realize those aims.

Driving the news: This morning the White House unveiled a nonbinding goal under the Paris Agreement that calls for cutting U.S. greenhouse gas emissions by 50%-52% by 2030 relative to 2005 levels.

Biden pledges to cut greenhouse gas emissions by up to 52% by 2030

U.S. President Joe Biden seen in the Oval Office on April 15. (Photo by Doug Mills-Pool/Getty Images)

The Biden administration is moving to address global warming by setting a new, economy-wide greenhouse gas emissions reduction target of 50% to 52% below 2005 levels by 2030.

Why it matters: The new, non-binding target is about twice as ambitious as the previous U.S. target of a 26% to 28% cut by 2025, which was set during the Obama administration. White House officials described the goal as ambitious but achievable during a call with reporters Tuesday night.