Pierre Kosc got interested in comics through reading Coq Hardi, Hourrah and Vaillant. He took courses in drawing at the age of 16, and got consultations from Victor Hubinon. In 1955, he began a collaboration with Fernand Cheneval's Héroïc Albums, for which he made 'Les Aventures du Commissaire Maroff' with scriptwriter Georges Leunis under the collective signature of P. Leika (Leunis + Kosc). He drew ten stories until Heroic cancelled publication in December, 1956. An eleventh story of 'Commissaire Maroff' was published years later in Curiosity Magazine by Michel Deligne. After Héroïc, Kosc moved on to create another character, the boxer 'Rocky Carter'. Starting in 1958, he made five long episodes of 'Valentin' in Germinal magazine. These stories were later reprinted by Samedi Jeunesse. Kosc then went to work for Libelle, drawing 'Spit et Patche', and left the comic scene afterwards.
He returned to comics in 1978 when Michel Deligne asked him to contribute an ode to Maurice Tillieux in Curiosity # 29. Kosc had assisted Tillieux on 'Félix' in 1956 and on 'Zappy Max' in 1959. A year later, he took on the adventures of 'Mike Cougar', of which two albums were published by Michel Deligne. Although retired, Kosc has enjoyed working on the retro comics of 'L'Inspecteur Caryton' for his own pleasure, of which the first was published by La Vache Qui Médite in 2011.