Table 2.

Objective response rates in the placebo-treated versus Palladia-treated dogs at the end of the 6-wk blinded phase and in all dogs treated with Palladia in the combined blinded and open-label phases

Objective response
6-wk blinded phase
P*Combined blinded and open-label phases
Placebo
Palladia
Placebo-escape
Palladia
No. in groupNo. (%)No. in groupNo. (%)No. in groupNo. (%)No. in groupNo. (%)
Total population635 (7.9)8632 (37.2)0.0004§5824 (41.4)8738 (43.7)
Lymph node involvement0.699
    No384 (10.5)5222 (42.3)3817 (44.7)5327 (50.9)
    Yes251 (4.0)3410 (29.4)207 (35.0)3411 (32.4)
Central pathology tumor grade0.058
    I20 (0.0)0NA11 (100.0)0NA
    II415 (12.2)6925 (36.2)3814 (36.8)7031 (44.3)
    III200 (0.0)177 (41.2)199 (47.4)177 (41.2)
Lymph node-tumor gradeNot done
    No-I10 (0.0)0NA11 (100)0NA
    No-II274 (14.8)4419 (43.2)2711 (40.7)4524 (53.3)
    No-III100 (0.0)83 (37.5)105 (50.0)83 (37.5)
    Yes-I10 (0.0)0NA0NANANA
    Yes-II141 (7.1)256 (24.0)113 (27.3)257 (28.0)
    Yes-III100 (0.0)94 (44.4)94 (44.4)94 (44.4)
Juxtamembrane c-kit mutation0.482
    No sample0NA20 (0)0NA20 (0.0)
    Negative544 (7.4)6420 (31.3)4917 (34.7)6525 (38.5)
    Positive91 (11.1)2012 (60.0)97 (77.8)2013 (65.0)
Prior chemotherapy1.00
    No364 (11.1)4720 (42.6)3514 (40.0)4722 (46.8)
    Yes271 (3.7)3912 (30.8)2310 (43.5)4016 (40.0)
Prior radiation therapy0.166
    No593 (5.1)8131 (38.3)5422 (40.7)8237 (45.1)
    Yes42 (50.0)51 (20.0)42 (50.0)51 (20.0)
Age in y1.00
    ≤9303 (10.0)4919 (38.8)2813 (46.4)5023 (46.0)
    >9332 (6.1)3713 (35.1)3011 (36.7)3715 (40.5)
Sex1.00
    Female374 (10.8)5019 (38.0)3314 (42.4)5125 (49.0)
    Male261 (3.8)3613 (36.1)2510 (40.0)3613 (36.1)
Performance status1.00
    0-Normal625 (8.1)7930 (38.0)5723 (40.4)8036 (45.0)
    1-Restricted10 (0.0)72 (28.6)11 (100.0)72 (28.6)
Median duration of therapy in d (range)21 (6-49)42 (7-49)97 (2-735)63 (7-812)
  • NOTE: All objective responses in the placebo group were partial responses. Objective responses in the Palladia group included 7 (8.1%) complete responses and 25 (29.1%) partial responses.

  • * P value for test of the interaction of treatment by covariate. The test for chemotherapy, radiation, age, sex and performance status were adjusted for multiple comparisons using the Hochberg method (SAS, proc multtest) due to these tests being unplanned comparisons.

  • Dogs treated with placebo in the blinded phase that were treated with Palladia in the open-label phase; includes one dog excluded from the blinded phase efficacy analysis because it received one dose of prednisone within 2 wk of enrollment.

  • Dogs treated with Palladia in the blinded phase; includes one dog excluded from the blinded phase efficacy analysis because it received one dose of prednisone within 2 wk of enrollment.

  • § Odds ratio, 6.46; 95% confidence interval, 2.3-18.3.