Until the recent introduction of phenylalanine mustard, the chemotherapy of multiple myeloma has been unsatisfactory. The use of agents such as urethane, stilbamidine derivatives, corticosteroids, radioactive phosphorus, mitomycin C, or combination of agents has not resulted in uniformly observed, objective responses in large numbers of patients. Although X-ray therapy and corticosteroids have been of some benefit, each of these agents alone has not been effective in producing either marked objective responses or increased survival.
Phenylalanine mustard, an oral alkylating agent, had been shown to have an anti-tumor effect, with the L-isomer (Melphalan, L-Sarcolysin) being most effective against animal and human