Split poly(A) Tail mRNA Patents Ruled Invalid for Obviousness

A recent ruling by a U.S. federal court has sent ripples through the biotechnology and pharmaceutical industries, declaring key patents involving split poly(A) tail mRNA technology invalid due to obviousness. The decision marks a significant development in the increasingly competitive mRNA therapeutics space, with potential implications for patent strategies and innovation pathways across the sector.

Background on Split Poly(A) Tail Technology

The poly(A) tail, a stretch of adenine nucleotides added to the 3' end of eukaryotic mRNA, plays a critical role in mRNA stability, translation efficiency, and nuclear export. In recent years, researchers and biotech firms have explored modified or split poly(A) tail structures as a way to enhance the performance of synthetic mRNA therapeutics, particularly in vaccines and gene therapies.

The patents in question were filed by a prominent biotech company seeking to protect a method of engineering mRNA molecules with a non-contiguous poly(A) tail—commonly referred to as a "split" poly(A) tail. This structural modification was claimed to improve stability and translational efficiency while circumventing certain manufacturing constraints.

The Legal Challenge

The challenge to the patents was brought by a competing biotechnology firm, which argued that the claimed invention was obvious in light of prior art. Specifically, the challengers pointed to multiple published studies and patent filings from the early 2010s and 2020s that explored non-traditional mRNA tailing strategies, including the use of segmented or partially synthetic poly(A) tails.

In a detailed opinion, the court agreed, concluding that the patent claims lacked the inventive step necessary to justify protection. “A person of ordinary skill in the art, with knowledge of existing mRNA modifications and stabilization techniques, would have been motivated to explore split poly(A) structures with a reasonable expectation of success,” the ruling stated.

Implications for the Biotech Industry

The decision is being closely watched across the life sciences sector, especially by companies investing heavily in mRNA technologies beyond COVID-19 vaccines, including oncology, rare disease therapeutics, and personalized medicine.

Legal experts suggest the ruling could signal a tougher stance on biotech patents, particularly those that rely on incremental modifications to known biological systems. “This case reinforces the need for genuine innovation in biotech patent filings,” said Dr. Leah Morgan, a biotech IP attorney. “If your invention is a minor variation of known methods or structures, courts are increasingly willing to strike it down as obvious.”

What's Next?

The patent holders are expected to appeal the decision, arguing that the split poly(A) tail approach represents a non-obvious advance due to its unexpected performance benefits and practical utility. However, the ruling may already influence future patent drafting and prosecution strategies, encouraging companies to document the technical advantages and unexpected results of their innovations more rigorously.

In the meantime, the invalidation of these patents may open the door for broader experimentation and commercialization of split poly(A) mRNA constructs by other players in the space—potentially accelerating progress but also intensifying competition.

For ongoing updates on this case and other biotech IP developments, stay tuned