US-based RNA-based vaccine developer Moderna Therapeutics has received $125m in series H funding from pharmaceutical firm Merck & Co as part of an expanded collaboration agreement.

Incubated by venture capital firm Flagship Ventures in 2010 and recently backed by the Singapore government-owned EDBI and Abu Dhabi Investment Authority, Moderna is developing therapeutics and vaccines based on messenger RNA (mRNA) molecules that target cancer and infectious, rare and cardiovascular diseases.

Messenger RNA is a family of molecules that deliver genetic information from the DNA to the ribosome, where they control how cells synthesise proteins.

The Merck partnership revolves around the development and commercialisation of a cancer vaccine, mRNA-5671, that will now be advanced into human studies. The companies now operate a total of four collaborations and may work together on other treatments in future.

Merck will be responsible for the clinical development of mRNA-5671 while Moderna will be in charge of clinical supply. Each party will be responsible for the respective associated costs of their duties.

Merck has the right to opt in to further development and commercialisation activities once human proof-of-concept studies are completed. It will pay an undisclosed fee to Moderna should it choose to pursue that option, and will then share the net profit and cost of the treatment.

Moderna has raised almost $1.75bn to date, having closed a $500m series G round in February 2018 that featured Alexandria Venture Investments, a division of life sciences real estate trust Alexandria Real Estate Equities.

The round also included financial services firm Julius Baer, Fidelity Management & Research, BB Biotech, Sequoia Capital China, Pictet, Viking Global Investors, ArrowMark Partners, EDBI and Abu Dhabi Investment Authority.

Pharmaceutical firm AstraZeneca supplied $140m for Moderna in 2016 as part of a $474m round that featured unnamed new and existing backers.

AstraZeneca and fellow drug producer Alexion Pharmaceuticals had already taken part in a $450m round for Moderna in 2015 alongside Flagship, Viking Global Investors, Invus, RA Capital Management, Wellington Management Company and undisclosed existing investors.