Based on diisocyanate prepolymer (DPP), the series of polyurethane-urea (PUU) with fragments of polyvinyl alcohol-polyethylene glycol (PVA-PEG) graft copolymer and 4,4’-diaminodiphenylmethane (DADPh) macrochain extender in the structure at different molar ratios of DPP:DADPh:PVA-PEG (1.0:0.7:0.3; 1.0:0.8:0.2; 1.0:0.9:0.1) were synthesized. Composite materials with the drug dacarbazine (DAС) in the amount of 1.0 wt.% based on the obtained PUU were developed. Studies of the structure and properties of PUU and composite materials with DAC based on them were carried out. The immobilization of DAC was found to be due to intermolecular hydrogen bonds by means of IR spectroscopy. According to the results of physical-mechanical tests, the introduction of DAC into the composition of PUU causes a non-significant decrease in the physical-mechanical properties, which is probably associated with a decrease in the packing density of macrochains of the polymer matrix. According to DSC, the studied systems are single-phase with a glass transition temperature (Tg) ranging from -12.50 to -31.99 °C. The introduction of DAC into the composition of PUU causes an increase in Tg and the specific heat capacity at the values of the glass transition temperature, which can be caused by a change in chain mobility due to the introduction of the filler and is correlated with the data of physical-mechanical tests. According to the results of hydrophilicity studies the introduction of PVA-PEG graft-copolymer into the PUU structure and increasing its content leads to an increase in hydrophilicity, which will contribute to a prolonged release of DAC from the polymer matrix. Therefore, the obtained composites with DAC are promising materials that can be used in medical practice as biologically active polymeric materials with a prolonged effect of an anticancer drug.