The in vivo antitumor activity of NCS-immune IgG (NCS conjugated with rabbit IgG antibody against the human leukemia cell line NALL-1) was evaluated in immunosuppressed newborn Syrian hamsters implanted with a transplantable human leukemia cell line (BALL-1). After i.p. injection of the conjugate, hamsters preinoculated i.p. with BALL-1 cells survived longer than hamsters treated with control solutions (p<0.01). The control solutions included NCS, immune IgG, a mixture of NCS and immune IgG, NCS-normal IgG conjugate and physiological saline. Growth retardation was not observed in NCS-immune IgG treated hamsters. The growth of s.c. implanted BALL-1 tumors was inhibited by i.p. administrations of NCS-immune IgG, however, the degree of inhibition was not significantly different from that obtained by NCS alone, a mixture of NCS and immune IgG or NCS-normal IgG conjugate. These results indicate that NCS-immune IgG was effective against i.p. implanted BALL-1 tumors, but was no so effective against s.c. implanted tumors.
In vivo antitumor activity
Transplantable human leukemia cells