Dirk J. Reitsma

Bio: Dirk J. Reitsma is an academic researcher from Novartis. The author has contributed to research in topics: Pamidronic acid & Breast cancer. The author has an hindex of 12, co-authored 19 publications receiving 7625 citations. Previous affiliations of Dirk J. Reitsma include University of California, Los Angeles & University of Texas MD Anderson Cancer Center.

Efficacy of Pamidronate in Reducing Skeletal Events in Patients with Advanced Multiple Myeloma

Abstract: Background Skeletal complications are a major clinical manifestation of multiple myeloma. These complications are caused by soluble factors that stimulate osteoclasts to resorb bone. Bisphosphonates such as pamidronate inhibit osteoclastic activity and reduce bone resorption. Methods Patients with stage III multiple myeloma and at least one lytic lesion received either placebo or pamidronate (90 mg) as a four-hour intravenous infusion given every four weeks for nine cycles in addition to antimyeloma therapy. The patients were stratified according to whether they were receiving first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy at entry into the study. Skeletal events (pathologic fracture, irradiation of or surgery on bone, and spinal cord compression), hypercalcemia (symptoms or a serum calcium concentration >12 mg per deciliter [3.0 mmol per liter]), bone pain, analgesic-drug use, performance status, and quality of life were assessed monthly. Results Among 392 treated patients, th...

Efficacy of Pamidronate in Reducing Skeletal Complications in Patients with Breast Cancer and Lytic Bone Metastases

Abstract: Background Bisphosphonates such as pamidronate disodium inhibit osteoclast-induced bone resorption associated with cancer that has metastasized to bone. Methods Women with stage IV breast cancer who were receiving cytotoxic chemotherapy and had at least one lytic bone lesion were given either placebo or pamidronate (90 mg) as a two-hour intravenous infusion monthly for 12 cycles. Skeletal complications, including pathologic fractures, the need for radiation to bone or bone surgery, spinal cord compression, and hypercalcemia (a serum calcium concentration above 12 mg per deciliter [3.0 mmol per liter] or elevated to any degree and requiring treatment), were assessed monthly. Bone pain, use of analgesic drugs, performance status, and quality of life were assessed throughout the trial. Results The efficacy of treatment was evaluated in 380 of 382 randomized patients, 185 receiving pamidronate and 195 receiving placebo. The median time to the occurrence of the first skeletal complication was greater in the pa...

Zoledronic acid versus pamidronate in the treatment of skeletal metastases in patients with breast cancer or osteolytic lesions of multiple myeloma: a phase III, double-blind, comparative trial.

Abstract: PURPOSE Zoledronic acid, a new and more potent bisphosphonate, was compared with pamidronate, the current standard treatment for patients with osteolytic or mixed bone metastases/lesions. PATIENTS AND METHODS A total of 1,648 patients with either Durie-Salmon stage III multiple myeloma or advanced breast cancer and at least one bone lesion were randomly assigned to treatment with either 4 or 8 mg of zoledronic acid via 15-minute intravenous infusion or 90 mg of pamidronate via 2-hour intravenous infusion every 3 to 4 weeks for 12 months. The primary efficacy endpoint was the proportion of patients experiencing at least one skeletal-related event over 13 months. RESULTS The proportion of patients with at least one skeletal-related event was similar in all treatment groups. Median time to the first skeletal-related eventwas approximately 1 year in each treatment group. The skeletal morbidity rate was slightly lower in patients treated with zoledronic acid than in those treated with pamidronate, and zoledronic acid (4 mg) significantly decreased the incidence and event rate for radiation therapy to bone, both overall and in breast cancer patients receiving hormonal therapy. Pain scores decreased in all treatment groups in the presence of stable or decreased analgesic use. Zoledronic acid (4 mg) and pamidronate were equally well tolerated; the most common adverse events were bone pain, nausea, fatigue, and fever and < 5% of serious adverse events were related to the study drug. The incidence of renal impairment among patients treated with 4 mg of zoledronic acid via 15-minute infusion was similar to that among patients treated with pamidronate. CONCLUSIONS Zoledronic acid (4 mg) via 15-minute intravenous infusion was as effective and well tolerated as 90 mg of pamidronate in the treatment of osteolytic and mixed bone metastases/lesions in patients with advanced breast cancer or multiple myeloma. (Can-

Long-term efficacy and safety of zoledronic acid compared with pamidronate disodium in the treatment of skeletal complications in patients with advanced multiple myeloma or breast carcinoma: a randomized, double-blind, multicenter, comparative trial.

Abstract: BACKGROUND The goal of the current study was to compare the long-term (25-month) safety and efficacy of zoledronic acid with pamidronate in patients with bone lesions secondary to advanced breast carcinoma or multiple myeloma. METHODS Patients (n = 1648) were randomized to receive 4 mg or 8 mg (reduced to 4 mg) zoledronic acid as a 15-minute infusion or to receive 90 mg pamidronate as a 2-hour infusion every 3–4 weeks for 24 months. The primary endpoint was the proportion of patients with at least 1 skeletal-related event (SRE), defined as pathologic fracture, spinal cord compression, radiation therapy, or surgery to bone. Secondary analyses included time to first SRE, skeletal morbidity rate, and multiple-event analysis. Hypercalcemia of malignancy (HCM) was included as an SRE in some secondary analyses. RESULTS After 25 months of follow-up, zoledronic acid reduced the overall proportion of patients with an SRE and reduced the skeletal morbidity rate similar to pamidronate. Compared with pamidronate, zoledronic acid (4 mg) reduced the overall risk of developing skeletal complications (including HCM) by an additional 16% (P = 0.030). In patients with breast carcinoma, zoledronic acid (4 mg) was significantly more effective than pamidronate, reducing the risk of SREs by an additional 20% (P = 0.025) compared with pamidronate and by an additional 30% in patients receiving hormonal therapy (P = 0.009). Zoledronic acid (4 mg) and pamidronate were tolerated equally well. The most common adverse events included bone pain, nausea, and fatigue. CONCLUSIONS Long-term follow-up data confirm that zoledronic acid was more effective than pamidronate in reducing the risk of skeletal complications in patients with bone metastases from breast carcinoma and was of similar efficacy in patients with multiple myeloma. Cancer 2003. © 2003 American Cancer Society. DOI 10.1002/cncr.11701

Zoledronic acid versus placebo in the treatment of skeletal metastases in patients with lung cancer and other solid tumors: a phase III, double-blind, randomized trial--the Zoledronic Acid Lung Cancer and Other Solid Tumors Study Group.

Abstract: Purpose: To assess the efficacy and safety of zoledronic acid in patients with bone metastases secondary to solid tumors other than breast or prostate cancer. Patients and Methods: Patients were randomly assigned to receive zoledronic acid (4 or 8 mg) or placebo every 3 weeks for 9 months, with concomitant antineoplastic therapy. The 8-mg dose was reduced to 4 mg (8/4-mg group). The primary efficacy analysis was proportion of patients with at least one skeletal-related event (SRE), defined as pathologic fracture, spinal cord compression, radiation therapy to bone, and surgery to bone. Secondary analyses (time to first SRE, skeletal morbidity rate, and multiple event analysis) counted hypercalcemia as an SRE. Results: Among 773 patients with bone metastases from lung cancer or other solid tumors, the proportion with an SRE was reduced in both zoledronic acid groups compared with the placebo group (38% for 4 mg and 35% for 8/4 mg zoledronic acid v 44% for the placebo group; P = .127 and P = .023 for 4-mg an...

Multiple myeloma

Abstract: Multiple myeloma (MM) is an incurable plasma cell dyscrasia that remains fatal. Despite efforts over the past 3 to 4 decades, the median survival of patients with MM does not exceed 3 to 4 years. Although patients receiving combination chemotherapy have higher response rates compared with those receiving oral melphalan and prednisolone, they have no survival advantage. High-dose chemotherapy followed by autologous stem cell transplantation has documented benefit over conventional treatment and is currently the accepted mode of treatment for symptomatic MM. Allogeneic transplantation is associated with high complete remission rates, but at the cost of high therapy-related mortality. Maintenance treatment with interferon-a shows benefit, albeit in a small fraction of MM patients. The use of bisphosphonates in patients with MM has clearly demonstrated benefit and reduced morbidity associated with bone disease. All of these measures have improved remission rates and survival, but all patients with MM ultimately relapse and succumb to their disease. Novel therapeutic strategies are therefore required to improve outcome of MM patients. The responses noted to thalidomide in MM are encouraging. Immune-based strategies, including both adoptive immunotherapy and vaccinations, are currently being investigated in the preclinical and clinical setting, with the goal of enhancing autologous and allogeneic anti-MM immunity for therapeutic applications.