What happened

Companies associated with gene-editing are near the end of their second poor week in a row on Wall Street. For the week, shares of CRISPR Therapeutics (CRSP 3.22%) were down by 12% as of Thursday's market close. Editas Medicine (EDIT 7.77%) was off by about 14% over those four days, and Beam Therapeutics (BEAM 7.34%) had lost 15%.

Those downward moves came on the heels of a huge June run-up after Intellia Therapeutics (NTLA 4.44%) -- another gene-editing company -- announced that its approach had successfully reversed a genetic disease in human patients. In a clinical trial first, researchers injected a CRISPR treatment into patients that effectively inactivated the body's production of a mutated (and eventually toxic) form of a protein by altering the patients' DNA. Intellia and its partner Regeneron will now navigate the standard regulatory review process. Intellia CEO John Leonard has said he hopes the therapy becomes available to patients "very, very soon." However, marketability could still be years away. Meanwhile, Wall Street's recent surge of excitement about CRISPR therapies has worn off.

BEAM Chart

BEAM data by YCharts

So what

The drops are notable as investors initially saw this breakthrough result as a positive for all gene-editing stocks. CRISPR Therapeutics, Editas, and Intellia are all taking similar approaches to editing genes -- using the CRISPR-Cas9 enzyme, which functions like a scissors. Beam Therapeutics, on the other hand, uses base-editing, an approach that alters DNA more like a pencil and eraser. Nearly three weeks removed from Intellia's announcement, the market has clearly decided its breakthrough is much more company-specific.

A researchers cutting out a gene from a double-helix DNA structure.

Image source: Getty Images.

Now what

It appears gene-editing investors who don't hold Intellia will have to wait for their own companies' catalysts to see big gains. Of these three, CRISPR Therapeutics is the one whose lead candidate is furthest along in clinical trials. CRISPR and its partner, Vertex Pharmaceuticals, have dosed more than 40 patients in a trial studying CTX001 in patients with sickle cell and beta-thalassemia. All patients at least three months removed from the procedure have shown a consistent and positive response to CTX001. Every previously transfusion-dependent patient in the trial has become transfusion-free since receiving the one-time treatment.

CTX001 is currently in a phase 1/2 study, and CRISPR Therapeutics hasn't offered any estimates about when it anticipates that it could be commercially available. But it recently signed an agreement with a smaller startup, Capsida Biotherapeutics, to develop an in vivo therapy for two diseases -- amyotrophic lateral sclerosis (ALS) and Friedreich's ataxia.

Editas has both in vivo and ex vivo (gene-editing done outside the body) candidates in early-stage clinical trials. Its in vivo candidate, EDIT-101, is a treatment for the most common form of childhood blindness. For this program, management has a meeting scheduled with the independent data monitoring committee this summer, and plans to share clinical data by the end of the year. 

The company's also developing an ex vivo treatment for sickle cell disease that takes a slightly different approach than the one being used by other gene-editing companies. Editas is using the Cas12a enzyme instead of the more commonly used Cas9. The Cas12a approach has shown better editing efficiency in some studies and only requires one RNA molecule for editing as opposed to Cas9, which requires two. 

For now, Beam Therapeutics is furthest back on the research and development path. Its programs are in preclinical stages. Its most advanced candidate also targets sickle cell disease and beta-thalassemia.

Investors' excitement about Beam has been less about its individual treatments and more about the gene-editing technology the company is using. Its base-editing approach could offer a more precise and predictable tool to modify DNA for treating diseases. The company hopes that will allow it to effectively leapfrog its rivals in the next few years. Management has predicted it will file with the FDA for an investigational new drug (IND) designation for its lead candidate later this year. Receiving that designation will give it the green light to test the treatment in humans trials. It also plans to move two more programs into the IND-enabling stage.