The rumour mill is running wild with renewed reports of a possible marriage between Dublin, Ireland-based Shire and US group NPS Pharmaceuticals.

As first reported by Bloomberg, citing sources close to the situation, Shire is considering making an offer for NPS should its flagship hormone replacement therapy Natpara receive a green light from US regulators.

Natpara (recombinant human parathyroid hormone) was filed with the US Food and Drug Administration in October for the treatment of hypoparathyroidism, and a decision is expected towards the end of January.

Though neither party has yet commented on the move, shares in NPS had leapt 20% and Shire’s stock was up nearly 3% in mid-afternoon trading on the Nasdaq on Wednesday.

Interestingly, these are not the first whispers of such a deal; back in June various media reports were suggesting that Shire is planning to make an offer in the region of $4 billion for NPS, though these soon were quashed by the US group.