Merck KGaA confirmed Thursday it had completed its $1.3bn acquisition of Silence Therapeutics, the London-listed developer of small interfering RNA treatments, cementing the German group's expansion into genetic medicines. The deal was announced earlier this week.

Silence Therapeutics specialises in RNA interference technology designed to silence disease-causing genes. Its lead asset, zerlasiran, targets lipoprotein(a), a genetic risk factor for cardiovascular disease, and has advanced through mid-stage clinical testing. The acquisition gives Merck KGaA control of that programme and Silence's broader siRNA platform.

Merck KGaA, based in Darmstadt, said the transaction strengthened its healthcare division as it seeks growth beyond its established oncology and fertility franchises. The purchase reflects a strategic bet on RNA-based therapeutics, a field dominated to date by firms such as Alnylam Pharmaceuticals and Novartis.

The completion signals continued consolidation among large pharmaceutical groups racing to secure RNA and gene-silencing technologies amid patent cliffs on legacy products. Analysts at Jefferies described the price as reflecting the scarcity value of late-stage cardiovascular RNA assets. Shares in Silence ceased trading on Nasdaq following the close.

Merck KGaA chief executive Belen Garijo has pledged to rebuild the company's drug pipeline through targeted acquisitions after several late-stage setbacks. The Silence deal ranks among the group's larger biotech purchases in recent years.