I have found two sources in Pubmed:
1.) Quote: "Piclamilast was provided by Aventis Pharmaceuticals"
Zhao et al., (2003) Inhibitor Binding to Type 4 Phosphodiesterase (PDE4) Assessed
Using [3H]-Piclamilast and [3H]-Rolipram.
JPET Fast Forward. Published on January 24, 2003 as DOI:10.1124/jpet.102.047407
2.) Quote: " N-(3,5-dichloropyrid-4-yl)-3-cyclopentyloxy-4-methoxybenzamide (piclamilast) was synthesized by Altana Pharma GmbH (Konstanz, Germany). "
Parrella et al., (2004) Phosphodiesterase IV Inhibition by Piclamilast Potentiates the Cytodifferentiating Action of Retinoids in Myeloid Leukemia Cells
J. Biol. Chem., Vol. 279, Issue 40, 42026-42040, October 1, 2004