Efficacy of pipobroman in the treatment of polycythemia vera: long-term results in 163 patients.
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BACKGROUND AND OBJECTIVES: Polycythemia vera (PV) is a myeloproliferative disorder, characterized by the expansion of the red cell mass. Our purpose was to evaluate the efficacy of pipobroman (PB) in the long-term control of PV and to assess early and late events. DESIGN AND METHODS: From June 1975 to December 1997, 163 untreated patients with PV (median age 57 years, range 30-82) were treated with PB in a single Institute for a median follow-up of 120 months. The diagnosis was made according to the Polycythemia Vera Study Group criteria. PB was given at the dose of 1 mg/kg/day until hematologic response (hematocrit < 45% and platelets < 400x109/L) and of 0.3-0.6 mg/kg/day as maintenance therapy. RESULTS: Hematologic remission was achieved in 94% of patients in a median time of 13 weeks (range 6-48). Median overall survival was 215 months, with a standardized mortality ratio of 1.7. The cumulative risk of death was 11%, 22%, and 26% at 7, 10, and 12 years, respectively. The incidence of thrombotic events was 18.4x105 person-year and the cumulative risk was 6%, 11%, 16%, and 20% at 3, 7, 10, and 12 years respectively. Acute leukemia occurred in 11 patients, myelofibrosis in 7, and solid tumors in 11. The 10-year cumulative risk of leukemia, myelofibrosis, and solid tumors was 5%, 4%, and 8%, respectively. In the logistic analysis age over 65 (p = 0.0001) and thrombotic events at diagnosis (p = 0.001) were significantly correlated with a higher risk of death. Female gender (p = 0.02) and age over 65 (p = 0.01) significantly influenced the occurrence of thrombotic complications. Age was the only significant risk factor for leukemia (p = 0.04) and for solid tumors (p = 0.03), while the duration of PB treatment did not influence these risks. No significant risk factor was demonstrated for myelofibrosis. INTERPRETATION AND CONCLUSIONS: This study demonstrates in a large series of patients, observed for a long period, that pipobroman is effective in the long-term control of PV. The risk of early thrombotic complications at 3 years is 6% and the 10-year risk of acute leukemia, late myelofibrosis, and solid tumors is 5%, 4%, and 8%, respectively. The duration of pipobroman treatment did not correlate with these events. (+info)
Acute myeloid leukemia (AML) having evolved from essential thrombocythemia (ET): distinctive chromosome abnormalities in patients treated with pipobroman or hydroxyurea.
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ET is a chronic myeloproliferative disorder rarely evolving into AML, sometimes preceded by a myelodysplastic syndrome (MDS). Such transformations mostly occur in patients treated with radiophosphorous ((32)P) or alkylating agents, especially busulfan. Recently, concern has also arisen about the long-term safety of hydroxyurea (HU). Pipobroman (PI), a well tolerated and simple to use drug, constitutes a valid alternative to those cytoreductive treatments. The present study reports on 155 ET patients treated at our institution from 1985 to 1995, and monitored until December 2000. A good control of thrombocytosis was achieved with PI as the only treatment in 106 patients and with HU in 23 patients. Twenty-six patients received no treatment. After a median follow-up of 104 months, seven patients (four treated with HU, and three with PI) developed AML whereas one patient treated with PI developed MDS. A significant difference in progression-free survival was observed between HU- and PI-treated patients (P = 0.004). A short-arm deletion of chromosome 17 was most frequently detected in HU-treated patients, while a long-arm trisomy of chromosome 1 and a monosomy 7q were seen in PI-treated patients. No TP53 mutation was discovered in the six patients studied (two HU-treated and four PI-treated). We conclude that these cytogenetic abnormalities are not linked to the natural history of the disease, but rather that they might be induced by the cytoreductive treatment. (+info)
Treatment of polycythemia vera with hydroxyurea and pipobroman: final results of a randomized trial initiated in 1980.
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Efficacy trial of pipobroman in polycythemia vera and incidence of acute leukemia.
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A trial was conducted between 1970 and 1981 with pipobroman (PB) in 100 consecutive patients with polycythemia vera (PV), followed for a median time of 60 months, to evaluate the efficacy of this drug and assess the risk of acute leukemia. Phlebotomy was not done before PB was given. Hematologic remission was achieved in 92% of previously untreated patients in a median time of 12 weeks (range, 6-48 weeks) and maintained for a median of 48 months. Acute hematologic toxicity was absent. The median overall survival was 140 months with 65% five-year complication-free survival; the overall death rate at 12 years was 23% (6% of patients died of thrombotic complications). The actuarial risk of acute leukemia was 6% and 9% at five and seven years, and the time from the diagnosis of PV to leukemia ranged from 14 to 81 months. Myelofibrosis occurred in three patients and lung carcinoma in one. All leukemias were nonlymphoid with prominent monocytic component and dyserythropoiesis. One patient had erythroleukemia, two cases were heralded by preleukemia with chromosomal abnormalities, one involving the chromosomes 5 and 7. PB is effective in PV; however, despite an easy induction of remission, continuous low-dose maintenance is necessary and the risk of subsequent acute leukemia is still significant. (+info)
Pipobroman therapy of polycythemia vera.
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Between 1971 and 1981, 74 patients with polycythemia vera were treated with pipobroman using a high-dose induction, low-dose maintenance regimen. Complete remission was achieved in 51 of 54 previously untreated patients (94.4%) and in 17 of 20 patients (85%) previously treated wih radioactive phosphorus (32 p) and busulfan. The earliest modifications were noted on day 16, and on the average, blood counts were normal by day 45. Thirty percent of the patients relapsed, the mean duration of the remission being 17.5 mo. Following recurrence pipobroman was consistently effective in the same doses but the mean duration of the next remissions was 10 mo. Transient leukopenia and thrombocytopenia occurred in 8% and 7% of patients, respectively, during initial phase, and anemia was noted in 3 patients. Macrocytosis was noted in 20% of patients during maintenance phase. Three cases of acute leukemia and 3 cases of osteomyelosclerosis were recorded, all occurring in patients who had previously received 32 p and/or busulfan. No hematologic malignancies were seen among patients treated with pipobroman alone; follow-up exceeded 6 yr for 20 patients and the median follow-up period was 3.6 yr. Pipobroman appears safer than other alkylating agents; it is as effective as 32 p and works more quickly. Longer follow-up will be required to evaluate the drug's oncogenic potential, which is still not known. (+info)
Myelodysplastic transformation in a case of essential thrombocythemia treated with pipobroman.
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Essential thrombocythemia (ET) is a clonal disorder of the myeloid stem cell that causes pathologic expansion of the megakaryocytic elements in the bone marrow, with a persistent increase in the platelet count. In order to avoid the mutagenic effects of radioactive phosphorous and alkylating agents, various European clinicians use pipobroman rather than hydroxyurea as single chemotherapeutic treatment, since it is simple and well tolerated and does not lead to hematological complications or the risk of visceral cancer. Here we describe a 63-year-old ET patient who showed myelodysplastic transformation (RAEB-t) of the primary disease after about eight years of therapy with pipobroman at variable dosages. (+info)
Treatment of polycythemia vera: the use of hydroxyurea and pipobroman in 292 patients under the age of 65 years.
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Nonradiomimetic drugs, hydroxyurea (HU) and pipobroman (Pi), were administred to relatively young subjects with polycythemia vera (PV) in an attempt to decrease the leukemogenic risk observed in patients treated with 32P. Clinical safety, hematological efficacy, risk of carcinoma or leukemia, and frequency of progression to myelofibrosis have not yet been defined in long-term studies, and no comparative studies of HU and Pi have been conducted. Since 1980, 292 patients with PV diagnosed before the age of 65 years were randomized to receive treatment with HU (25 mg/kg/d, followed by low-dose maintenance) or Pi (1.2 mg/kg/d, followed by low-dose maintenance). Patients were followed until death or until May 1997. Drug tolerance was often poor; leg ulcers and buccal aphthous ulcers (with HU) and gastric pain and diarrhea (with Pi) sometimes required treatment change, mainly in the HU arm. Hematological stability, especially in terms of platelet count, was very often insufficient with HU (45% of cases), but the risk of thrombo-embolic event was similar in both arms. Actuarial survival was similar in the two arms and shorter than that of the reference population. The risk of leukemia was approximately 10% at the 13th year, with no significant difference between the two arms. The risk of carcinoma (when excluding the skin cancers) was similar in both groups. There was a high risk of progression to myelofibrosis in the patients treated by HU, which was significantly higher than with Pi. (+info)