What happened

Shares of Intellia Therapeutics (NTLA -1.10%) were trading 40.3% higher as of 11:05 a.m. EDT Monday, after the company and its partner, Regeneron (REGN 0.61%), announced encouraging interim results on Saturday from a phase 1 clinical study evaluating NTLA-2001 as a treatment for the rare genetic disease transthyretin (ATTR) amyloidosis.

So what

The biotech stock vaulted so much higher because investors realized the significance of Intellia's update. The interim results for NTLA-2001 were the first clinical data ever that supported the safety and efficacy of in vivo (in the body) CRISPR gene editing in humans.

DNA images with a healthcare professional in the background.

Image source: Getty Images.

Intellia and Regeneron reported that a single dose of NTLA-2001 achieved an 87% mean reduction in serum transthyretin (TTR) protein levels. There was a maximum serum TTR reduction of 96% by day 28. This is highly encouraging since the current standard of care, Alnylam's Onpattro, typically achieves TTR reductions of 80%. Onpattro also requires dosing every three weeks, whereas NTLA-2001 is a one-time treatment.

The safety profile for NTLA-2001 also looked good. Intellia and Regeneron stated that there were no serious adverse events reported as of 28 days after treatment.

There were only six patients covered in the trial's interim data release. Intellia and Regeneron couldn't have asked for better results at this point, though.

Now what

Intellia's next step will be to present additional data from its phase 1 study of NTLA-2001 at a medical or scientific conference later this year. The company also plans to add another cohort to the study in 2021.

However, the importance of the promising safety and efficacy for the experimental CRISPR therapy goes beyond just one indication. Intellia CEO John Leonard said that this milestone "unlocks the door to treating a wide array of other genetic diseases with our modular platform, and we intend to move quickly to advance and expand our pipeline."