14 CLINICAL STUDIES
The safety and efficacy of Doxercalciferol Injection have been established based on adult studies of doxercalciferol injection in patients with CKD on hemodialysis. Below is a display of the results of these studies of doxercalciferol injection.
The safety and effectiveness of doxercalciferol injection was evaluated in two open-label, single-arm, multi-center clinical studies (Study C and Study D) in a total of 70 patients with CKD on hemodialysis. Patients in Study C were an average age of 54 years (range: 23 to 73), were 50% male, and were 61% African-American, 25% Caucasian, and 14% Hispanic, and had been on hemodialysis for an average of 65 months. Patients in Study D were an average age of 51 years (range: 28 to 76), were 48% male, and 100% African-American and had been on hemodialysis for an average of 61 months. This group of 70 of the 138 patients who had been treated with doxercalciferol capsules in prior clinical studies received doxercalciferol injection in an open-label fashion for 12 weeks following an 8-week washout (control) period. Dosing of doxercalciferol injection was initiated at the rate of 4 mcg administered at the end of each dialysis session (3 times weekly) for a total of 12 mcg per week. The dosage of doxercalciferol injection was adjusted to achieve intact PTH levels (measured weekly) within a targeted range of 150 pg/mL to 300 pg/mL. The dosage was increased by 2 mcg per dialysis session after 8 weeks of treatment if the intact PTH levels remained above 300 pg/mL and were greater than 50% of baseline levels. The maximum dosage was limited to 18 mcg per week. If at any time during the study intact PTH fell below 150 pg/mL, doxercalciferol injection was immediately suspended and restarted at a lower dosage the following week. Mean weekly doses ranged from 9 mcg to 13 mcg in Study C and ranged from 9 mcg to 12 mcg in Study D.
Fifty-two (74%) of the 70 patients who were treated with doxercalciferol injection achieved intact PTH levels ≤300 pg/mL. Forty-one (59%) of these patients exhibited plasma intact PTH levels ≤300 pg/mL on at least 3 occasions. Thirty-six (51%) patients had plasma intact PTH levels <150 pg/mL on at least one occasion during study participation. Decreases in plasma intact PTH from baseline values were calculated using as baseline the average of the last 3 values obtained during the 8-week washout period and are displayed in Table 3.
| Intact PTH Level | Study C (n=28) | Study D (n=42) | Combined Protocols (n=70) |
|---|---|---|---|
| Baseline (Mean of Weeks -2, -1, and 0) | |||
| Mean (SE) | 698 (60) | 762 (65) | 736 (46) |
| Median | 562 | 648 | 634 |
| On-treatment (Week 12*) | |||
| Mean (SE) | 406 (63) | 426 (60) | 418 (43) |
| Median | 311 | 292 | 292 |
| Change from Baseline† | |||
| Mean (SE) | -292 (55) | -336 (41) | -318 (33) |
| Median | -274 | -315 | -304 |
| P-value‡ | 0.004 | 0.001 | <0.001 |
Doxercalciferol injection treatment resulted in at least 30% reduction from baseline in mean intact PTH levels during the 12-week open-label treatment period in more than 92% of the 70 treated patients.