Lancer (lanthanide citrate) is a feed additive mainly consisting of two rare earth elements, lanthanum (La) and cerium (Ce), in their citrate forms. Lancer has not been previously authorised in the European Union. In 2013, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) issued an opinion on the safety and efficacy of Lancer as a zootechnical feed additive for weaned piglets. In its opinion the FEEDAP Panel could not conclude on the safety of the additive for the target species, on the safety for the consumer and on the safety for the environment. As a result of the additional information provided by the applicant, the FEEDAP Panel concluded that the additive Lancer is safe for weaned piglets when used at the maximum recommended dose of 250 mg/kg complete feed. In view of concerns over the possible developmental neurotoxicity of La, the many gaps in the available toxicological information on Ce and La, the absence of studies of long-term toxicity, carcinogenicity, reproductive toxicity and developmental toxicity of Lancer, and the absence of residue data in edible tissues, the FEEDAP Panel cannot conclude on the safety of Lancer for the consumer. In the absence of adequate data the FEEDAP Panel cannot conclude on the safety of Lancer for the environment.