Steven L. Soignet

Complete Remission after Treatment of Acute Promyelocytic Leukemia with Arsenic Trioxide

BACKGROUND Two reports from China have suggested that arsenic trioxide can induce complete remissions in patients with acute promyelocytic leukemia (APL). We evaluated this drug in patients with APL in an attempt to elucidate its mechanism of action. METHODS Twelve patients with APL who had relapsed after extensive prior therapy were treated with arsenic trioxide at doses ranging from 0.06 to 0.2 mg per kilogram of body weight per day until visible leukemic cells were eliminated from the bone marrow. Bone marrow mononuclear cells were serially monitored by flow cytometry for immunophenotype, fluorescence in situ hybridization, reverse-transcription-polymerase-chain-reaction (RT-PCR) assay for PML-RAR-alpha fusion transcripts, and Western blot analysis for expression of the apoptosis-associated proteins caspases 1, 2, and 3. RESULTS Of the 12 patients studied, 11 achieved complete remission after treatment that lasted from 12 to 39 days (range of cumulative doses, 160 to 495 mg). Adverse effects were relatively mild and included rash, lightheadedness, fatigue, and musculoskeletal pain. Cells that expressed both CD11b and CD33 (antigens characteristic of mature and immature cells, respectively), and which were found by fluorescence in situ hybridization to carry the t(15;17) translocation, increased progressively in number during treatment and persisted in the early phase of complete remission. Eight of 11 patients who initially tested positive for the PML-RAR-alpha fusion transcript by the RT-PCR assay later tested negative; 3 other patients, who persistently tested positive, relapsed early. Arsenic trioxide induced the expression of the proenzymes of caspase 2 and caspase 3 and activation of both caspase 1 and caspase 3. CONCLUSIONS Low doses of arsenic trioxide can induce complete remissions in patients with APL who have relapsed. The clinical response is associated with incomplete cytodifferentiation and the induction of apoptosis with caspase activation in leukemic cells.

United States Multicenter Study of Arsenic Trioxide in Relapsed Acute Promyelocytic Leukemia

PURPOSE To determine the safety and efficacy of arsenic trioxide (ATO) in patients with relapsed acute promyelocytic leukemia (APL). PATIENTS AND METHODS Forty patients experiencing first (n = 21) or > or = second (n = 19) relapse were treated with daily infusions of ATO to a maximum of 60 doses or until all leukemic cells in bone marrow were eliminated. Patients who achieved a complete remission (CR) were offered one consolidation course of ATO that began 3 to 4 weeks later. Patients who remained in CR were eligible to receive further cycles of ATO therapy on a maintenance study. RESULTS Thirty-four patients (85%) achieved a CR. Thirty-one patients (91%) with CRs had posttreatment cytogenetic tests negative for t(15;17). Eighty-six percent of the patients who were assessable by reverse transcriptase polymerase chain reaction converted from positive to negative for the promyelocytic leukemia/retinoic acid receptor-alpha transcript by the completion of their consolidation therapy. Thirty-two patients received consolidation therapy, and 18 received additional ATO as maintenance. Eleven patients underwent allogeneic (n = 8) or autologous (n = 3) transplant after ATO treatment. The 18-month overall and relapse-free survival (RFS) estimates were 66% and 56%, respectively. Twenty patients (50%) had leukocytosis (> 10,000 WBC/microL) during induction therapy. Ten patients developed signs or symptoms suggestive of the APL syndrome and were effectively treated with dexamethasone. Electrocardiographic QT prolongation was common (63%). One patient had an absolute QT interval of > 500 msec and had an asymptomatic 7-beat run of torsades de pointe. Two patients died during induction, neither from drug-related causes. CONCLUSION This study establishes ATO as a highly effective therapy for patients with relapsed APL.

Effect of Arsenic Trioxide on QT Interval in Patients With Advanced Malignancies

PURPOSE Arsenic trioxide is an effective treatment for patients with acute promyelocytic leukemia (APL) who have relapsed from or are refractory to all-trans-retinoic acid and anthracycline chemotherapy. Since arsenic can prolong the QT interval and lead to torsade de pointes, a life-threatening ventricular arrhythmia, this retrospective analysis was conducted to determine the degree of QT prolongation in patients treated with arsenic trioxide. PATIENTS AND METHODS Clinical data and serial ECGs from 99 patients with advanced malignancies who received 170 courses of arsenic trioxide in either a phase I or phase II investigational study were reviewed. RESULTS Prolonged QT intervals developed in 38 patients (26 patients had intervals >/= 500 milliseconds). Compared with baseline, the heart rate-corrected (QTc) interval was prolonged by 30 to 60 milliseconds in 36.6% of treatment courses, and by more than 60 milliseconds in 35.4% of patients. The degree of prolongation was higher in men than in women during the first course of therapy, and in patients with hypokalemia. In patients receiving multiple courses, QTc intervals returned to pretreatment levels before the second course, signifying that arsenic trioxide does not permanently prolong the QTc interval. One hypokalemic, arsenic trioxide-treated patient with relapsed APL developed asymptomatic torsade de pointes, which resolved spontaneously and did not recur after electrolyte replacement. There were no sudden or arrhythmia-related deaths. CONCLUSION This analysis shows that arsenic trioxide can prolong the QTc interval. However, with appropriate ECG monitoring and management of electrolytes and concomitant medications, arsenic trioxide can be safely administered in patients with relapsed APL.

Leukocytosis and the Retinoic Acid Syndrome in Patients With Acute Promyelocytic Leukemia Treated With Arsenic Trioxide

PURPOSE Arsenic trioxide, like all-trans-retinoic acid (RA), induces differentiation of acute promyelocytic leukemia (APL) cells in vivo. Treatment of APL patients with all-trans RA is commonly associated with leukocytosis, and approximately 50% of patients develop the RA syndrome. We reviewed our clinical experience with arsenic trioxide to determine the incidence of these two phenomena. PATIENTS AND METHODS Twenty-six patients with relapsed or refractory APL were treated with arsenic trioxide for remission induction at daily doses that ranged from 0.06 to 0.17 mg/kg. RESULTS Twenty-three patients (88%) achieved complete remission. Leukocytosis was observed in 15 patients (58%). The median baseline leukocyte count for patients with leukocytosis was 3,900 cells/microL (range, 1,200 to 72,300 cells/microL), which was higher than that for patients who did not develop leukocytosis (2,100 cells/microL; range, 500 to 5,400 cells/microL; P =.01). No other cytotoxic therapy was administered, and the leukocytosis resolved in all cases. The RA syndrome was observed in eight patients (31%). Patients who developed leukocytosis were significantly more likely to develop the RA syndrome (P <.001), and no patient without a peak leukocyte count greater than 10,000 cells/microL developed the syndrome. Among the patients with leukocytosis, there was no observed relation between the leukocyte peak and the probability of developing the syndrome (P =.37). CONCLUSION Induction therapy of APL with all-trans RA and arsenic trioxide is associated with leukocytosis and the RA syndrome. These clinical effects seem to be intrinsically related to the biologic responsiveness and the differentiation process induced by these new agents.

Intraperitoneal Chemotherapy for Ovarian Carcinoma: Results of Long-Term Follow-Up

PURPOSE To determine long-term survival and predictors of recurrence in a retrospective cohort of patients with epithelial ovarian cancer treated with intraperitoneal (IP) chemotherapy. PATIENTS AND METHODS Records were reviewed of 433 patients who received IP therapy for ovarian cancer between 1984 and 1998; follow-up data were available for 411 patients. IP therapy was provided as consolidation therapy (n = 89), or for treatment of persistent (n = 310) or recurrent (n = 12) disease after surgery and initial systemic therapy; therapy usually consisted of platinum-based combination therapy. Statistical analysis included tests for associations between potential prognostic factors, and between prognostic factors and survival. Survival probabilities were estimated by Kaplan-Meier methods, and prognostic factors for survival were evaluated by a Cox proportional hazard model. RESULTS The mean age of patients was 52 years (range, 25 to 76 years). Distribution by stage and grade was as follows: stage I, 7; II, 24; III, 342; IV, 52; not available (NA), 8; and grade 1, 30; 2, 99; and 3, 289; NA, 15. The median survival from initiation of IP therapy by residual disease was none, 8.7 years; microscopic, 4.8 years; less than 1 cm, 3.3 years; more than 1 cm, 1.2 years. In a multivariate analysis, the only significant predictors of long-term survival were grade and size of residual disease at initiation of IP therapy. CONCLUSION Prolonged survival was observed in selected patients receiving IP platinum-based therapy. It is not possible to determine the contribution of IP therapy to survival in this study. A relationship between size of disease at the initiation of IP therapy and long-term survival was demonstrated.

Pilot study of combination transcriptional modulation therapy with sodium phenylbutyrate and 5-azacytidine in patients with acute myeloid leukemia or myelodysplastic syndrome.

Epigenetic mechanisms underlying tumorigenesis have recently received much attention as potential therapeutic targets of human cancer. We designed a pilot study to target DNA methylation and histone deacetylation through the sequential administration of 5-azacytidine followed by sodium phenylbutyrate (PB) in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Ten evaluable patients (eight AML, two MDS) were treated with seven consecutive daily subcutaneous injections of 5-azacytidine at 75 mg/m2 followed by 5 days of sodium PB given intravenously at a dose of 200 mg/kg. Five patients (50%) were able to achieve a beneficial clinical response (partial remission or stable disease). One patient with MDS proceeded to allogeneic stem cell transplantation and is alive without evidence of disease 39 months later. The combination regimen was well tolerated with common toxicities of injection site skin reaction (90% of the patients) from 5-azacytidine, and somnolence/fatigue from the sodium PB infusion (80% of the patients). Correlative laboratory studies demonstrated the consistent reacetylation of histone H4, although no relationship with the clinical response could be demonstrated. Results from this pilot study demonstrate that a combination approach targeting different mechanisms of transcriptional modulation is clinically feasible with acceptable toxicity and measurable biologic and clinical outcomes.

All-trans retinoic acid significantly increases 5-year survival in patients with acute promyelocytic leukemia: long-term follow-up of the New York study

Abstract All-trans retinoic acid (ATRA) induces a high incidence of complete remission (CR) in patients with acute promyelocytic leukemia (APL); however, the magnitude of this agent’s contribution to increased rates of cure of this disease has not yet been established. From 1990 to 1995 we used RA as remission induction therapy in 103 APL patients (73 newly diagnosed and 30 previously treated) who were retinoid-naive and were treated on the basis of initial morphology. Patients whose diagnosis was changed on the basis of the results of molecular testing (n = 13) were withdrawn from RA treatment and given chemotherapy alone. After achieving a CR, previously untreated patients received several cycles of consolidation chemotherapy, usually with idarubicin and cytosine arabinoside. Among individuals whose diagnosis was molecularly confirmed, 54 of 65 new patients (83%) and 25 of 30 previously treated patients (83%) achieved a CR. All induction failures in molecularly diagnosed cases were due either to early death or to premature withdrawal. Median disease-free and overall survival rates recorded for all newly diagnosed patients are currently >40+ and >43+ months, respectively. We subsequently examined a subset of 27 newly diagnosed patients treated during the first 2 years of this program whose actual median follow-up period is now >5 years. Median disease-free and overall survival rates recorded for this group are >57+ and >58+ months, respectively; 56% of these patients are alive in first remission. These results significantly exceed those achieved using chemotherapy alone in a historical control group of 80 patients consecutively treated at this center from 1975 to 1990, whose median disease-free and overall survival rates were 11 and 19 months, respectively; only 22% of these patients were alive in first remission at 5 years. Although a high proportion of previously treated patients also achieved a CR after RA treatment, median disease-free and overall survival rates noted for that group were markedly lower (i.e., 7.5 and 10.9 months, respectively). Thus, data from patients whose median follow-up period is now >5 years have confirmed earlier projections and indicate that the use of RA for remission induction yields an approximately 2.5-fold increase in the proportion of patients who have presumably been cured of this disease.

Clinical study of an organic arsenical, melarsoprol, in patients with advanced leukemia

Abstract Inorganic arsenic trioxide (As2O3) induces a high proportion of complete remissions in relapsed patients with acute promyelocytic leukemia (APL). Previously, we have shown that both As2O3 and melarsoprol, an organic arsenical used for the treatment of trypanosomiasis, exhibit broad antileukemic activity against both chronic and acute myeloid and lymphoid leukemia cell lines. Given the breadth of this activity, we initiated a clinical study to evaluate the pharmacokinetics, safety, and potential efficacy of melarsoprol in patients with refractory or resistant leukemia. Using the antitrypanosomal dose and schedule, patients received escalating intravenous doses daily for 3 days, repeated weekly for 3 weeks. Doses were 1 mg/kg on day 1, 2 mg/kg on day 2, and 3.6 mg/kg on day 3 and on all days thereafter, up to a maximum daily dose of 200 mg. Eight patients [6 AML (2 morphologic APL), 1 CML, 1 CLL] were treated. Mean peak plasma concentrations of the parent drug were obtained immediately after injection, ranged from 1.2 μg/ml on day 1 to 2.4 μg/ml on day 3, were dose proportional, and decayed with a t1/2≅ 15 min. A minor clinical response (regression of splenomegaly and lymphadenopathy) was observed in a patient with chronic lymphocytic leukemia. Central nervous system (CNS) toxicity proved limiting on this dose and schedule. Three patients experienced generalized grand mal seizures during the second week of therapy. We concluded that this dose and schedule of melarsoprol is associated with excessive CNS toxicity and that verification of the striking preclinical activity in patients with leukemia will require developing an alternative dose and schedule.

Pharmacokinetics and safety of ILX23-7553, a non-calcemic-vitamin D3 analogue, in a phase I study of patients with advanced malignancies

Purpose: Differentiation therapy is an alternative to chemotherapy with potentially less toxicity, improved quality of life, and survival. We conducted a phase I trial of ILX23-7553, a formulation of 1,25-dihydroxy-16-ene-23-yne-vitamin D3, a 1,25-dihydroxyvitamin D3 analog with preclinically demonstrated antitumor and differentiating effects and diminished hypercalcemic effects. Patients and methods: The protocol consisted of five daily oral treatments during 14-day cycles at 15 dose levels from 1.3 to 45.0 μg/m2/day. We treated 42 heavily pretreated patients who had a variety of malignancies with 162 treatment cycles, and obtained pharmacokinetics from three patients at the two highest dose levels. Results: There were no grade 3 or 4 toxicities. Grade 1–2 toxicities included diarrhea, nausea, fatigue, constipation, and one grade 1 hypercalcemia. Average day 6 calcium was 9.26 ± 0.55 mg/dl in cycle 1 and 9.30 ± 0.67 mg/dl in cycle 2. Pharmacokinetics at dose levels 14 (40 μg/m2/day) (1 patient) and 15 (45 μg/m2/day) (2 patients) demonstrated an average Cmax of 30.4 ± 7.8 pg/ml (0.07 nM) and 104 ± 38.2 pg/ml (0.25 nM), and AUCs of 222.5 ± 225.2 pg·h/ml and 855 ± 536 pg h/ml, respectively. Eight patients (19%) had stable disease. While in vitro effects have been reported at these concentrations, they were at least 10-fold lower than ED50s, and the study was terminated before an MTD was reached. Conclusion: The drug is safe and has potential benefits at serum concentrations where effects begin to be noted in vitro. Further study is needed with a reformulated higher unit dose compound to determine the safety and efficacy of higher serum concentrations.

Phase I and Pharmacokinetic Study of the Novel Oral Cell-Cycle Inhibitor Ro 31-7453 in Patients With Advanced Solid Tumors

PURPOSE To determine maximum tolerated dose, pharmacokinetics (PK), and safety of Ro 31-7453, a novel, oral cell-cycle inhibitor. PATIENTS AND METHODS Using an accelerated dose-escalation schedule, 48 patients with advanced solid tumors were treated with doses of Ro 31-7453 ranging from 25 to 800 mg/m(2)/d given for 4 consecutive days, every 3 weeks. The total daily dose was taken as a single dose (schedule A) or divided into two equal doses taken 12 hours apart (schedule B). PK samples of blood and urine were collected on the first and last days of dosing in cycles 1 and 2. RESULTS Forty-five patients completed at least one cycle of therapy. Myelosuppression and stomatitis were dose-limiting toxicities, occurring at the 800 mg/m(2)/d dose level for both schedules. Toxicity was independent of body-surface area, leading to the recommended phase II flat dose of 1,000 mg daily for 4 days for both schedules. Common adverse events included diarrhea, nausea, vomiting, fatigue, alopecia, and elevated liver-function tests. One death, related to neutropenic sepsis, occurred on study. The PK of the parent compound and major metabolites were apparently linear, with a half-life of approximately 9 hours and a maximum concentration of approximately 4 hours. Minor antitumor activity was observed against carcinoma of the lung, breast, pancreas, and ovary. CONCLUSION Ro 31-7453 was well tolerated, with manageable adverse effects. Significant PK variability (absorption, metabolism, and excretion) was observed, and a substantial number of additional patients are needed to confirm the recommended phase II dose. Additional pharmacology and phase II studies are under way to explore the dose-toxicity relationship.