Single-agent arsenic trioxide in the treatment of newly diagnosed acute promyelocytic leukemia: long-term follow-up data.

PURPOSE We previously reported our results with a single-agent arsenic trioxide (ATO) -based regimen in newly diagnosed cases of acute promyelocytic leukemia (APL). The concern remained about the long-term outcome of this well-tolerated regimen. We report our long-term follow-up data on the same cohort. PATIENTS AND METHODS From January 1998 to December 2004, 72 patients with PML/RARalpha+ APL were enrolled. All patients were treated with a single-agent ATO regimen. Results Overall 62 (86.1%) achieved a hematologic remission (complete remission). After the initial report, an additional seven patients have relapsed for a total of 13 relapses. There were no additional toxicities to report on follow-up. At a median follow-up 60 months, the 5-year Kaplan-Meier estimate (+/- SE) of event-free survival, disease-free survival, and overall survival (OS) was 69% +/- 5.5%, 80% +/- 5.2%, and 74.2% +/- 5.2%, respectively. The OS in the good risk group as defined by us remains 100% over this period. CONCLUSION Single-agent ATO as used in this study in the management of newly diagnosed cases of APL is safe and is associated with durable responses. Results in the low-risk group are comparable to that reported with conventional therapy while additional interventions would probably be required in high-risk cases.

Single-agent arsenic trioxide in the treatment of newly diagnosed acute promyelocytic leukemia: durable remissions with minimal toxicity.

Arsenic trioxide, as a single agent, has proven efficacy in inducing molecular remission in patients with acute promyelocytic leukemia (APL). There is limited long-term outcome data with single-agent As2O3 in the management of newly diagnosed cases of APL. Between January 1998 to December 2004, 72 newly diagnosed cases of APL were treated with a regimen of single-agent As2O3 at our center. Complete hematologic remission was achieved in 86.1%. At a median follow-up of 25 months (range: 8-92 months), the 3-year Kaplan-Meier estimate of EFS, DFS, and OS was 74.87% +/- 5.6%, 87.21% +/- 4.93%, and 86.11% +/- 4.08%, respectively. Patients presenting with a white blood cell (WBC) count lower than 5 x 10(9)/L and a platelet count higher than 20 x 10(9)/L at diagnosis (n = 22 [30.6%]) have an excellent prognosis with this regimen (EFS, OS, and DFS of 100%). The toxicity profile, in the majority, was mild and reversible. After remission induction, this regimen was administered on an outpatient basis. Single-agent As2O3, as used in this series, in the management of newly diagnosed cases of APL, is associated with responses comparable with conventional chemotherapy regimens. Additionally, this regimen has minimal toxicity and can be administered on an outpatient basis after remission induction.

Arsenic trioxide in the treatment of newly diagnosed acute promyelocytic leukemia: a single center experience.

Arsenic trioxide (As(2)O(3)) has been found effective in the treatment in the treatment of acute promyelocytic leukemia (APML). Most studies with As(2)O(3) involve patients with APML who have relapsed following standard therapy. Between January 1998 and July 2000, 14 patients were recruited for an ongoing trial of As(2)O(3) in the treatment of newly diagnosed APML. Arsenic trioxide was administered at a dose of 10 mg/day until complete remission (CR) was achieved. Afterward, a consolidation course and a maintenance schedule consisting of As(2)O(3) as a single agent were administered over 6 months. There were 3 early deaths related to intra-cerebral hemorrhage: two on day 3 and one on day 4. Of the 11 evaluable patients, one died on day 21 secondary to uncontrolled sepsis, while the remaining 10 (91%) have attained CR. The average time to CR was 52.3 days (range: 34-70 days). One patient developed an isolated central nervous system (CNS) relapse and subsequently went into a second CR following therapy with triple intrathecal chemotherapy, cranial irradiation, and an additional 4-week course of systemic As(2)O(3). This patient, as well as the remaining nine, has continued to remain in CR at a median follow up of 15 months (range: 2-33 months). Eight out of 10 patients achieved molecular remission at variable periods during their consolidation and maintenance schedules. One patient developed an ATRA syndrome and was administered daunorubicin (40 mg/day) for 2 days. The side effects with this therapy were minimal and did not require cessation of therapy in any patient. There was no significant hepatic toxicity. In our experience, arsenic trioxide is effective in inducing and maintaining remission in patients with APML with minimal side effects. The optimal regimen and total dose required need to be defined.