GSK acquires oligonucleotide drug startup Elsie

British drugmaker GSK is investing further in nucleic acid drug development, reaching a deal to buy the San Diego-based Elsie Biotechnologies for as much as $50 million.

GSK announced the deal Thursday, almost one year after beginning a research collaboration around oligonucleotides with the private biotechnology company. Buying Elsie will give GSK full access to the company’s discovery and delivery technologies, fitting into GSK’s broader commitment to explore oligonucleotide drugs.

The acquisition comes about four months after GSK exercised an option to license Elsie’s platform for an undisclosed upfront payment.

Oligonucleotides are small strands of DNA or RNA that can be used to craft drugs that alter gene expression. They’re now a well-established class of medicines that some companies, like GSK, are making more central to their development plans alongside standard proteins and pills.

GSK’s efforts around oligonucleotides also coincide with the company’s pivot away from cell therapies.

One of its most advanced candidates comes from Ionis Pharmaceuticals, an oligonucleotide pioneer that licensed a hepatitis B drug to GSK in 2019. GSK moved the drug, called bepirovirsen, into late-stage testing last year, and has highlighted it as a priority project.

GSK has struck a partnership with Cambridge-based Wave Life Sciences, too, paying $120 million in 2022 to start a four-year deal around oligonucleotide drugs. The pharma is also advancing an oligonucleotide candidate in liver disease.

“We have already made great strides in oligonucleotide drug development through our work in chronic hepatitis B and steatotic liver disease, and are thrilled to work alongside the talented team at Elsie to accelerate a next-generation oligonucleotide platform,” Tony Wood, chief scientific officer at GSK, said in a statement.