He was on the Today programme on Radio 4 yesterday.
He is moving to the US because the Ethics Committee will not allow it in UK. This is because they are worried that the pigs could fall back into the breeding chain and there would be no way of predicting what could happen.
In the US, genetic breeding is not regulated.

For many years now, pig heart valves have been used in cardiac surgery in the UK. This obviously poses a huge moral question when trying to save the life of a person whose religion doesn't permit pork.