The
tumor growth inhibitory efficacy of the
somatostatin structural derivative
TT-232 was studied using different routes of administration and treatment schedules in various human
tumor models.
TT-232, containing a five-residue ring structure, has a strong antitumor activity both in vitro and in vivo. The
antineoplastic activity of
TT-232 has been found to be associated with the induction of programmed cell death in
tumor cells, resulting in highly-selective elimination of the neoplastic tissue. The study compared the antitumor efficacy of
TT-232 in various long-term administration routes; the intermittent (injection) versus continuous (infusion) treatment via subcutaneously-inserted Alzet osmotic minipumps in different human
tumor models: T-47/D human
breast carcinoma and A-431 human
epidermoid carcinoma. Treatment with
TT-232 started after disease development. The antitumor activity of
TT-232 was evaluated on the basis of the
tumor growth inhibition. In the case of T-47/D human
breast carcinoma, the intermittent treatment resulted in 23%-26% and the infusion treatment resulted in 48%-53%
tumor growth inhibition. The
tumor growth inhibitory effect of
TT-232 on A-431 human
epidermoid carcinoma tumor resulted in 35%-43% (intermittent treatment) and 70%-74% (continuous treatment) decreases in
tumor volume. This antitumor efficacy of
TT-232 was observed in the two human
tumors investigated. In this study, the route of infusion was shown to increase
drug efficacy relative to conventional delivery methods. The results suggest that
TT-232 is an effective and promising
antitumor agent.