Zinostatin stimalamer is a new antineoplastic polymeric agent launched in Japan
for the treatment of hepatoma. It was synthesized by chemical conjugation of the
synthetic inert poty(styrene-maleic acid) (SMA) and neocarzinostatin (NCS), which
is a proteinaceous antitumor agent produced by Streptomyces carzinostaticus.
SMANCS not only retains the properties of NCS for inhibiting DNA synthesis in the
cell by direct DNA strand scission, but also is able to uniquely augment the host
defense system by inducing interferon γ and activating macrophages. Compared
with NCS, SMANCS has greatly improved in vitro and in vivo stability, is more
effective in reducing tumor size and in preventing the development of new tumors,
has decreased toxic side effects and extended plasma half life. In clinical trials,
tumor size reductions have been obtained in 90% of patients with hepatoma and
dose of 0.7 mg/m2 induced complete or almost complete necrosis of tumor without
affecting noncancerous liver tissue or the gallbladder.
