I agree with others, it is likely a form of Lilium primulinum (possibly closer to var. ochraceum), but the colour is certainly different. There are many new forms of these lilies emerging lately. The more of those I see, the more I realise how little we all know about this group, especially in the west. They are very beautiful lilies and I hope we continue to see many more such introductions.
The important thing here is to find someone with similar forms and exchange bulbs/pollen with a view to setting seed of this form/species. There are already too many "sterile" forms out there because we rely on vegetative propagation techniques.
