Biotechnology firm Alnylam Pharmaceuticals Inc has initiated fresh legal action against Pfizer Inc and Moderna Inc in Delaware federal court, alleging once again that the companies’ COVID-19 vaccines violate its patents.

This marks the third occasion on which Alnylam has sued Pfizer and Moderna in Delaware, accusing them of infringing its patent rights related to lipid nanoparticle (LNP) technology. The vaccines rely on this technology to deliver genetic material into the body, as reported by Reuters.

Alnylam is seeking an unspecified portion of the royalties from the sales of the companies’ vaccines.

In 2022, Pfizer generated $37.8 billion from its COVID-19 vaccine Comirnaty, while Moderna made $18.4 billion from Spikevax.

At the time of writing, Alnylam, Moderna, and Pfizer have not responded to requests for comments on the new lawsuits. Both Moderna and Pfizer have refuted the allegations in previous cases, asserting that Alnylam’s patents are invalid.

Alnylam, headquartered in Cambridge, Massachusetts, initially filed lawsuits against Moderna and Pfizer in March of last year. In July, it filed an additional set of complaints regarding another LNP patent, which were subsequently consolidated with the earlier lawsuits.

The lawsuits filed on Friday consist of four new infringement claims against Pfizer and three against Moderna.

These legal actions are part of a wider trend of patent lawsuits filed by biotech companies concerning COVID-19 vaccines, including a case brought by Moderna against Pfizer in Massachusetts last year.

Alnylam has informed the Delaware court that it played a pioneering role in developing LNP technology, which it considers ‘essential’ to the mRNA-based vaccines, over a decade ago.

The company has also stated that it shared confidential information about the technology with Moderna in 2014 during discussions about a potential collaboration.