wherein;

n is an integer from 1 to 50;

L² is a linking moiety selected from the group consisting of R¹⁴, C(O) R¹⁴C(O), C(O) R¹⁴N, NHR¹⁴NH, or C(O) NHR¹⁴NHC(O); wherein R¹⁴ is O, S, C₁-C₂₀ alkyl; C₁-C₂₀ heteroalkyl; C₁-C₂₀ alkylamine; C₁-C₂₀ alkoxyl; C₁-C₂₀ alkanoyloxyl; or C₁-C₂₀ alkylamido, any of which can be optionally substituted with one or more substituents including halogen, alkoxyl, alkyl, alkenyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, aryl, heteroaryl, amine, cyano, hydroxyl, carbonyl, acyl, carboxylic acid (—COOH), —C(O) R¹², primary amide (e.g., —CONH₂), secondary amide (e.g., —CONHR₁₂), —C(O) NR¹²R¹³, —NR¹²R¹³, —NR¹²S (O)₂R¹³, —NR¹²C(O) R¹³, —S(O)₂R¹², and —S(O)₂NR¹²R¹³, sulfinyl group (e.g., —SOR¹²), and sulfonyl group (e.g., —SOOR¹²); wherein R¹² and R¹³ can each independently be hydrogen, halogen, hydroxyl, alkyl, haloalkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, carbonyl, cyano, amino, alkylamino, dialkylamino, alkoxyl, aryloxyl, cycloalkyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, or dialkylaminocarbonyl;

Ab is an antibody that targets PD-1, PD-L1, CD137, OX40 or CD40; and

Dmt-Tic is represented by

wherein Dmt-Tic is linked to Formula I via an amide bond,

where R¹ and R² are independently selected from H and CH₃.