Table 4.
Reasons for Discontinuation of Cyclophosphamide*
| Reason | No. of affected patients | Events per person-year (95% Confidence Interval (CI)) | Kaplan-Meier estimate for ≤1 year (95% CI) |
|---|---|---|---|
| Favorable Reasons | |||
| Remission | 61 (28%) | 0.32 (0.24, 0.41) | ** |
| Unfavorable Reasons | |||
| Ineffectiveness | 19 (8.8%) | 0.099 (0.060, 0.15) | 9.7 (5.7 - 16.4) |
| Discontinuation for side effects | 75 (35%) | 0.39 (0.31, 0.49) | 33.5 (26.8 - 41.4) |
| Low leukocyte count | 38 (18%) | 0.20 (0.14, 0.27) | 18.1 (12.7 - 25.3) |
| Low platelet count | 3 (1.4%) | 0.016 (0.0032, 0.046) | 1.7 (0.4 - 7.2) |
| Anemia | 7 (3.3%) | 0.036 (0.015, 0.075) | 3.6 (1.6 - 8.1) |
| Opportunistic infection | 5 (2.3%) | 0.026 (0.0084, 0.061) | 1.3 (0.3 - 5.2) |
| (Fatal pneumocystosis | 1 (0.5%) | 0.0052 (0.0001, 0.029) | 0.5 (0.1 - 3.5)) |
| Cystitis/blood in urine | 14 (6.5%) | 0.073 (0.040, 0.12) | 7.7 (4.1 - 14.2) |
| Sterility | 1 (0.5%) | 0.0052 (0.0001, 0.029) | 0.5 (0.1 - 3.5) |
| Malaise | 1 (0.5%) | 0.0052 (0.0001, 0.029) | 0.5 (0.1 - 3.6) |
| Gastrointestinal upset | 1 (0.5%) | 0.0052 (0.0001, 0.029) | 0.5 (0.1 - 3.6) |
| Liver problem | 1 (0.5%) | 0.0052 (0.0001, 0.029) | 0.5 (0.1 - 3.5) |
| Other side effects | 12 (5.6%) | 0.062 (0.032, 0.11) | 7.9 (4.5 - 13.6) |
| Reasons Unknown | 20 (9.3%) | 0.10 (0.064, 0.16) | 7.7 (4.3 - 13.3) |
| Total Stopping Cyclophosphamide for Any Reason | 164 (76%) | 0.85 (0.72, 0.99) | 50.5 (43.5 - 57.9) |
*
More than one cause could have been scored as contributing to discontinuation of the drug
**
In most cases clinicians do not attempt discontinuation on grounds of potential disease remission until disease has been quiescent for an extended period of time after discontinuation of corticosteroids.3 The Kaplan-Meier estimate for discontinuation on grounds of remission at 2 and 3 years respectively was 63.1% and 74.8%