FAQ - Library proposals

Please note that the library submission tool now is closed to new registrants and submissions. The European Lead Factory thanks everybody for their contributions.

Library Proposals

What kind of proposals can I submit?

The EU Lead Factory seeks any compound design proposals that will complement its screening collection. A proposal needs to describe between 100 and 5000 compounds that might be prepared (for example, by decoration of a common scaffold).

Who can participate and submit chemistry proposals?

The European Lead Factory welcomes compound design proposals from anywhere in the world. In each case, you must determine who owns the proposal (or who has the ability to grant access, ownership, a license or a sublicense as required). In most cases, the owner will be either the inventor/scientist or his/her employer. If the inventor/scientist is not the owner, he/she may submit only in the name and on behalf of the owner.

How does the submission process work?

Initially, you will need to create a user profile within the dedicated web tool and a agree to the legal terms of use. You can then create your proposals, either by defining a scaffold and possible combinations of R-groups or by uploading a file (most likely, an SD file) that defines the whole compound. You will receive some initial feedback that may allow you to decide whether to submit your proposal, or whether it needs further refinement. Following assessment, you will find out whether your proposal has been accepted and you will also receive feedback on your proposal from the consortium’s Compound Selection Committee.

Who will assess my proposal?

All proposals are assessed by a Compound Selection Committee that comprises scientists representing partners within the EU Lead Factory. The committee has broad and complementary expertise in medicinal chemistry and synthesis. A balanced committee composition facilitates the selection of highly innovative proposals that address project objectives. Note that all members of the selection committee are bound to confidentiality.

What criteria are used to assess my proposal?

Compound design proposals will be assessed against six criteria:

  • Molecular properties – the drug-relevant molecular properties.1
  • Structural features – structural features that may constitute a liability in screening compounds (for example, alkylating agents, or potential intercalating compounds).
  • Novelty – novelty of the proposed compounds by comparison with a reference set of commercially-available and patented compounds.
  • Diversity potential – value of the proposed approach for the synthesis of compound of diverse compounds (it is usually preferable for a wide range of variable groups to be introduced late in the synthetic sequence).
  • Synthetic tractability – the likely synthetic accessibility of the compound based on the precedent provided.
  • Innovative compound design – the rationale that has been used for the design of the compound.


The outcome of the proposal is reached by the committee by tensioning all of the criteria against each other. Note that a rating of ‘exclude’ against any criterion will lead to rejection of a proposal.

1Some information on drug-relevant molecular properties may be found in the following papers: C. A. Lipinski et al, Adv. Drug Deliv. Rev. 1997, 23, 3; S. J. Teague et al, Angew. Chem. Int. Ed. 1999, 38, 3743; W. P. Walters et al, J. Med. Chem. 2011, 54, 6405.

Can I submit more the one proposal?

Yes. Once you have created your user profile you may submit as many compound design proposals as you like. All will be individually assessed.

Do I get a reward for my accepted library proposal?

You are eligible for payments if you are from an organisation in the EU/EAA that is not part of the consortium. The European Lead Factory offers three levels of financial reward for accepted proposals depending on the maturity of the idea.