TABLE 1.
Protection from tumor rechallenge following complete tumor eradication with i.t. chitosan/IL-12 immunotherapy
| Experiment | Number of mice |
Day of rechallenge |
Dose of rechallenge |
Partial protectiona | Complete protectionb |
|---|---|---|---|---|---|
| 1 | 8 | 56 | 200,000 | 3/8 (37.5%) | 5/8 (62.5%) |
| 2 | 5 | 56 | 300,000 | 2/5 (40%) | 2/5 (40%) |
| 3 | 4 | 126 | 300,000 | 1/4 (25%) | 1/4 (25%) |
| TOTAL | 6/17 (35%) | 8/17 (47%) | |||
NOTE: Mice experiencing complete regression of s.c. MC32a tumors following i.t. chitosan/IL-12 immunotherapy were rechallenged with either 200,000 or 300,000 MC32a cells in the opposite flank either 56 or 126 days after original tumor inoculation. Age-matched naïve mice (n = 5) challenged with the same number of cells served as controls.
a
Partial protection = ≥ 50% reduction in tumor volume vs. naïve controls after 2 weeks.
b
Complete protection = no measurable tumor mass 4 weeks after rechallenge.