The radiopharmaceutical drugs that will come on the market within the next ten to fifteen years will be limited to the ones for which large-scale manufacturing units under GMP conditions are available today or will be within the next five years:

This list seems quite short, but one must understand that other radionuclides could still be of interest, provided the developers find industrial partners that are ready to invest in the manufacturing tools for a worldwide distribution. If the development of a new radiotherapeutic agent is linked to a new radionuclide, it must be anticipated that the overall development of this new molecule will need at least 5 years more time to solve the radionuclide manufacturing issues.

We have seen some initiatives to bring new radionuclides on the market, and surprisingly in the field of alpha-emitters. The Arronax project will serve as the pilot project for the development of Astatine 211, but due to the short half-life of this radionuclide, investment to cover the expected marketing area will result in a need for investment probably higher than € 150 M. The same will happen for ²²⁵Ac. Actinium 225 will face, on top of this, further safety limitations due to the production of uncontrolled secondary alpha particles. Very recently, high quality grade ²¹²Pb was made available. This will probably be the second alpha-emitter of interest, next to ²¹¹At. However, as this radionuclide is new for the community, its advantages will have to be proven over the existing ones. In addition to that, further investments in terms of production will be mandatory. Finally, one has to mention ²²³Ra that will be produced under GMP conditions as it is part of the first alpha-emitter compound that will come on the market (Alpharadin-223-Radium chloride—from Algeta/Bayer Pharma).

The radionuclides with a future seen from the industry’s perspective are collected in Table 1. Just for the sake of comparison, imaging radionuclides have been added as well. This group has been divided into subgroups of short and long half-life radionuclides, property which is important in diagnosis where biological processes have to be taken into consideration (see Table 2). Half-life of radionuclides in therapeutics is of lower importance in terms of efficacy (also in the sense it is not a limiting factor), but definitely must be taken into consideration when accounting for the dosimetry to patient or to staff. The chemistry of the element, i.e., covalent binding versus chelating chemistry, has not been taken into account. With the exception of fluorine and iodine, it is hopeless to expect the development of new radionuclides that can be bound covalently. The future of therapeutics will definitely be based on chelating chemistry.