Alnylam soars on likely first RNAi treatment approval

Alnylam has been plugging away in the RNAi-based treatment area for 15 years and, finally, has something to show for its efforts. Revealing data from its treatment, patisran, for Hereditary ATTR (hATTR) Amyloidosis Patients with Polyneuropathy, the results are strong enough to make the long wait for first treatment worthwhile.

The biggest concern for the company throughout its long search for a viable treatment has been safety. The company may, in fact, have become more recognised for pulling the plug on clinical trials, such as the recent worrying death in a trial of fitusiran. It can now chalk these experiences up as part of the process in finding a treatment that looks potentially set to change the therapeutic landscape.

RNAi therapeutics work by silencing the gene expression that allow for the creation of disease-promoting proteins. This means that illnesses can be stopped at their source rather than by targeting the proteins that are already present.

In this case, the treatment will help those with hATTR – an inherited, progressively debilitating, and often fatal disease caused by mutations in the TTR gene. The results of the Phase 3 trial were that the treatment hit all of its primary and secondary endpoints. The primary endpoint being to show improvement in impairment scores, whilst secondary endpoints also included boosting muscle strength, walking improvement and gait speed, amongst others.

"We are very proud to report the first ever positive Phase 3 results for an RNAi therapeutic, marking the potential arrival of an entirely new class of medicines. This moment is the culmination of a 15-year journey of tireless work by countless contributors who have overcome enormous scientific and business challenges to make RNAi therapeutics a reality," said John Maraganore, Chief Executive Officer of Alnylam. "This is an incredibly exciting milestone for Alnylam and RNAi, and most importantly for patients and their treating physicians and families. We extend our deepest gratitude to all the patients, investigators and study staff who participated in the APOLLO study - they made this important scientific progress possible."

The biggest challenge was to display that the treatment was safe, and it managed to do this – even reporting less adverse events during treatment against placebo treatment. The full data of which will be released at a later medical event. Alnylam expects to file with the FDA by the end of the year and approval is anticipated during the course of 2018.

After the initial excitement had passed over the strong results, words of caution began to be expressed about the development of future treatments from some analysts. The significant jump in share price, up 47%, showed that people were banking on the technology behind the treatment to deliver even more treatments, effectively giving the company a steady stream of successes.

Analysts cautioned that difficulties seen in the safety profile of other treatment could be continued to be seen and raised concerns that the potential revenue from patisran may not be enough to offset operational costs unless another successful treatment is found.

At present, analysts expect patisran to reach $1 billion in peak sales. The drug will be marketed in US and Europe by Alnylam while Sanofi will market the treatment in the rest of the world.