Table 1.
Burkitt tumor response to human IP-10 treatment in athymic mice
| Treatment | Tumor size at first injection,* cm2 | No. of responses/total treated† | Tumor size of responders,* cm2 | Tumor size of nonresponders,* cm2 | % tumor tissue necrosis of responders‡ | % tumor tissue necrosis of all tumors‡ |
|---|---|---|---|---|---|---|
| Experiment 1 | ||||||
| None | — | 0/2 | — | 4.7 | — | 20 |
| LCL | 0.46 | 3/3 | 3.1 | — | 56.5 | 56.5 |
| Human IP-10 50 ng per day | 0.39 | 4/5 | 5.3 | 7.2 | 55.4 | 54.5 |
| Saline | 0.22 | 0/2 | — | 7.9 | — | 22 |
| Experiment 2 | ||||||
| None | — | 0/4 | — | 9 | — | 25 |
| LCL | 0.24 | 3/4 | 4.8 | 7.6 | 54.6 | 45.2 |
| Human IP-10 200 ng per day | 0.26 | 2/4 | 5.5 | 8.5 | 43 | 50 |
| Human IP-10 400 ng per day | 0.23 | 3/5 | 6.0 | 8.6 | 50 | 40.6 |
| Saline | 0.26 | 0/4 | — | 6.31 | — | 23 |
Nude mice bearing a Burkitt tumor induced as described were injected daily into the tumor with human recombinant IP-10. In experiment 1, human IP-10 was injected at the dose of 50 ng for 2 weeks, followed by 100 ng per day for 1 week, and 150 ng per day for 1 week. In experiment 2, one group was treated with an initial dose of 200 ng per day and the other with an initial dose of 400 ng per day. IP-10 doses were doubled when the tumor reached a size ≥2 cm2. The total number of IP-10 treatment days was 30 to 35. Tumor-bearing control animals were injected into the tumor either with LCL or with normal saline containing 1% BSA.
Calculated as the product of two-dimensional caliper measurement (longest perpendicular length and width); expressed as arithmetic mean for the group.
A tumor was considered responsive when it developed a visible area of necrosis (≥4 mm2 in size) that progressively increased in size on subsequent weekly observations.
The % tumor tissue necrosis was estimated by digital analysis of tumor cross-sections. The slides were scanned using a flat-bed scanner (Scanjet II CX, Hewlett–Packard), and necrotic/total tumor area measured.