An earlier formulation of Ragweed MATAMPL developed by Allergy Therapeutics (UK), Ltd, available commercially in Canada since the 1980's, is 'Pollinex®-R'. 'Pollinex®-R' is formulated with modified allergens (allergoids) of ragweed pollen extract adsorbed onto L tyrosine at 4% w/v. Related formulations developed by ATL, available commercially in selected European countries since the 1970´s on a Named Patient Basis, are 'Pollinex Tree', 'Pollinex Grass', 'Pollinex Quattro Trees' (previously known as MATA tree + MPL), and 'Pollinex Quattro Grass' (previously known as MATA grass + MPL).