In the synthesis of new superheavy nuclei, the various long half-lives of Pu and Cm isotopes render them promising target materials for fusion reactions. Investigating the isotopic dependence of actinide targets is important for selecting optimal reaction systems. Based on the dinuclear system model, the impact of the target isotope is investigated for the reactions \(^{48}\) Ca + \(^{239,240,242,244}\) Pu. The reaction systems with the \(^{242{-}248}\) Cm targets and the \(^{45}\) Sc, \(^{50}\) Ti, \(^{51}\) V, \(^{54}\) Cr, \(^{55}\) Mn projectiles are investigated for the synthesis of new isotopes \(^{284-290}\) Ts, \(^{289-293,295}\) Og, \(^{290{-}296}\) 119, \(^{293{-}299}\) 120, \(^{294{-}300}\) 121. The isotopic dependence of the Cm targets revealed an ascending trend of the maximal ER cross section coupled with an odd–even effect as the neutron number of the target increased, and the \(^{247}\) Cm target emerged as promising for future experiments. The optimal reactions for producing new superheavy elements with Z = 119–121 are predicted to be the reactions \(^{51}\) V + \(^{245}\) Cm, \(^{54}\) Cr + \(^{247}\) Cm, and \(^{55}\) Mn + \(^{247}\) Cm with maximal ER cross sections of 144 fb, 0.877 fb, and 0.052 fb, respectively.
