1. Compound 2 - [(4S) -6- (4-chlorophenyl) -1-methyl-8- (methyloxy) -4H- [1,2,4] triazolo [4,3-a] [1,4] benzodiazepin-4-yl] -N-ethylacetamide or a pharmaceutically acceptable salt thereof for use in the treatment of small cell lung cancer. A compound according to claim 1 in the form of a free base. 3. A method for treating small cell lung cancer in a subject in need thereof, comprising administering a therapeutically effective amount of 2 - [(4S) -6- (4-chlorophenyl) -1-methyl-8- (methyloxy) -4H- [1,2,4 ] triazolo [4,3-a] [1,4] benzodiazepin-4-yl] -N-ethylacetamide or a pharmaceutically acceptable salt thereof. The treatment method of claim 3, wherein the subject is a human. A pharmaceutical composition containing 2 - [(4S) -6- (4-chlorophenyl) -1-methyl-8- (methyloxy) -4H- [1,2,4] triazolo [4,3-a] [1,4 ] benzodiazepin-4-yl] -N-ethylacetamide or a pharmaceutically acceptable salt thereof, for use in the treatment of small cell lung cancer. The pharmaceutical composition according to claim 5, adapted for oral administration. Combined pharmaceutical product containing 2 - [(4S) -6- (4-chlorophenyl) -1-methyl-8- (methyloxy) -4H- [1,2,4] triazolo [4,3-a] [1, 4] benzodiazepin-4-yl] -N-ethylacetamide or a pharmaceutically acceptable salt thereof, as defined in paragraph 1 or paragraph 2, together with one or more additional therapeutically active agents suitable for use in the treatment of small cell lung cancer.1. Соединение 2-[(4S)-6-(4-хлорфенил)-1-метил-8-(метилокси)-4H-[1,2,4]триазоло[4,3-a][1,4]бензодиазепин-4-ил]-N-этилацетамид или его фармацевтически приемлемая соль для применения в лечении мелкоклеточного рака легкого.2. Соединение по п. 1 в форме свободного основания.3. Способ лечения мелкоклеточного рака легкого у субъекта, нуждающегося в этом, включающий введение терапевтически эффективного количества 2-[(4S)-6-(4-хлорфенил)-1-метил-8-(метилокси)-4H-[1,2,4]триазоло[4,3-a][1,4]бензодиазепин-4-ил]-N-этилацетамида или его фармацевтически приемлемой соли.4. Способ
