In a study recently published in the journal Clinical Lymphoma, Myeloma & Leukemia, researchers determined that continuous treatment with cyclophosphamide (Cytoxan) and prednisone at low doses is effective and manageable in multiple myeloma patients who cannot tolerate conventional chemotherapy.

When myeloma patients are unresponsive to treatment or experience relapse, doctors implement their plan B, known generally as salvage therapy. Most salvage therapies consist of the same treatment drugs at an increased dosage or a combination treatment of the same and new drugs. However, in patients who have health complications or who encounter severe side effects, a dose increase or the addition of a new drug may lead to more problems, so doctors must attempt other salvage therapies.

In this study, researchers examined the effectiveness and safety of continuous, low-dose cyclophosphamide and prednisone as a salvage therapy in 27 multiple myeloma patients. All of the patients either had health complications (such as kidney impairment, diabetes, or heart failure) or had experienced repeated infection from conventional chemotherapy.

Patients received 50 mg of cyclophosphamide and 15 mg of prednisone orally each day without a treatment-free interval. The treatment was stopped only if the patients did not achieve partial response within the first three months. Doctors followed up every two months for a median of 11 months.

After three months of continuous treatment, 18 of the 27 patients (66.7 percent) responded to the salvage therapy. Two patients (7.4 percent) achieved complete response, two patients (7.4 percent) achieved very good partial response, and 14 patients (51.9 percent) achieved partial response. Seven patients (25.9 percent) remained stable, and two (7.4 percent) experienced progressive disease.

In patients who achieved partial response or better, the median overall survival was 22 months. Median progression-free survival had not been reached yet at the time of data analysis. Patients who remained stable or had disease progression experienced a median overall survival of seven months and a median progression-free survival of four months.

Treatment-associated side effects included pneumonia (25.9 percent); physical traits characteristic of Cushing’s syndrome (14.8 percent), a hormone disorder due to high levels of cortisol in the blood; upper respiratory infection (7.4 percent); secondary diabetes (7.4 percent); fatigue (3.7 percent); and water retention (3.7 percent). Most were mild and manageable.

Researchers concluded that in patients with health complications that lead to organ dysfunction, continuous, low-dose cyclophosphamide and prednisone is a safe, effective, and practical salvage therapy in terms of cost and use. They described the treatment as a “promising alternative” to conventional chemotherapy.

For more information, please see the journal Clinical Lymphoma, Myeloma & Leukemia (abstract).