Biomedical subjects

L J Ayash

Publications and source records attributed to L J Ayash.

23 records · Page 2Linked to original sources

PubMed1992

Cyclophosphamide pharmacokinetics: correlation with cardiac toxicity and tumor response.

BACKGROUND: Cyclophosphamide, which forms the nucleus for virtually all preparative regimens for autologous bone marrow transplantation (ABMT), is an alkylating agent of which cytotoxicity is not directly caused by the parent compound but by its biologically active metabolites. Its nonmyelosuppressive toxicity in the ABMT setting is cardiomyopathy. We attempted to determine any correlation between plasma levels of total cyclophosphamide and the subsequent development of cardiac dysfunction. PATIENTS AND METHODS: Analyses of plasma levels and the derivation of plasma concentration-time curves (area under the curve [AUC]) were performed in 19 women with metastatic breast carcinoma, who received a continuous 96-hour infusion of cyclophosphamide, thiotepa, and carboplatin (CTCb) with ABMT. The assay for total cyclophosphamide measures the inactive parent compound; reliable assays of the active metabolites of cyclophosphamide are not yet available. RESULTS: Six of 19 women developed moderate, but transient, congestive heart failure (CHF) as assessed by clinical and radiologic criteria. These patients had a significantly lower AUC of total cyclophosphamide (median, 2,888 mumol/L/h) than patients who did not develop CHF (median, 6,121 mumol/L/h) (P less than .002). Median duration of tumor response in these patients was also more durable; at least 22 months in patients with lower AUCs versus a median of 5.25 months in those with higher AUCs (P = .008). CONCLUSION: These pharmacokinetic data support the premise that enhancement of cyclophosphamide activation may lead to both greater tumor cytotoxicity and increased but reversible end-organ toxicity. Early analysis of pharmacokinetic data may allow modulation of cyclophosphamide administration in an attempt to enhance therapeutic efficacy.

Adult↗

PubMed1991

Escalating doses of carboplatin with high-dose ifosfamide using autologous bone marrow as support: a phase I study.

In this phase I study, 16 adult cancer patients were treated with concurrent 4-day continuous infusions of ifosfamide at 12 g/m2 and escalating doses of carboplatin (400-1600 mg/m2) to determine the major non-haematological dose-limiting toxicity of the combination. Mesna was given by continuous infusion over 5 days for uroprotection (total dose per course = 15 g/m2). Autologous bone marrow support, which was mandated for subsequent dose levels once granulocytes remained below 500/microliters for more than 14 days in at least 2 patients entered at a given dose level, was used at dose levels above 400 mg/m2 carboplatin. Renal toxicity became dose-limiting at the maximum tolerated dose level of 1600 mg/m2 carboplatin. Temporary creatinine elevations above 2 mg/dl (median peak 2.6 mg/dl) were observed in 3 and irreversible renal toxicity occurred in 1 (peak creatinine 6.9 mg/dl, chronic creatinine 5-6 mg/dl) of the 5 patients entered at this dose level. Severe confusion and lethargy associated with rising creatinine developed in 2 patients. Two complete and four partial responses were documented in 14 heavily pretreated evaluable patients. The complete responses continue at 14+ and 20+ months in a patient with germ cell carcinoma and Ewing's sarcoma, respectively. Carboplatin appears to contribute to the renal toxicity of ifosfamide. Nevertheless, the combination of carboplatin and ifosfamide at 80% and 75% of the single-agent maximal tolerated doses respectively produced acceptable non-haematological toxicity. Further studies in the treatment of sarcoma, germ cell, ovarian and lung carcinomas with this combination are warranted.

Adult↗

PubMed1991

A phase I study of high-dose ifosfamide and escalating doses of carboplatin with autologous bone marrow support.

The dose-limiting toxicity in two separate phase I trials of the high-dose single agents ifosfamide and carboplatin was renal insufficiency at 18 g/m2 and hepatic and ototoxicity at 2,400 mg/m2, respectively. In this phase I study, 16 adults were treated with ifosfamide at 75% of the single-agent maximum-tolerated dose (MTD) (12 g/m2) and escalating doses of carboplatin (400 to 1,600 mg/m2) to determine the nonhematologic dose-limiting toxicity and the maximum-tolerated dose of the combination. Both drugs as well as mesna for uroprotection were given by continuous infusion over 4 days with an additional day of mesna (total dose per course, 15 g/m2). Autologous bone marrow support was stipulated for subsequent dose levels once granulocytes remained less than 500/microL for more than 14 days in two of three to five patients entered at a given dose level. Autologous bone marrow support was used at doses above the 400 mg/m2 carboplatin dose level. At the maximum-tolerated dose level of 1,600 mg/m2 of carboplatin, renal toxicity precluded further dose escalation. Of the five patients entered at this dose level, reversible creatinine elevation greater than 2 mg/dL (median peak, 2.6 mg/dL) was observed in three patients, and irreversible renal failure occurred in an additional patient (peak creatinine, 6.9 mg/dL. Transient gross hematuria appeared more common with the combination than with ifosfamide alone. Two patients developed severe somnolence and confusion associated with a rising creatinine. There were two complete (CRs) and four partial responses (PRs) in 14 heavily pretreated assessable patients (including four partial or complete responses in eight assessable patients with advanced refractory sarcoma, and one CR in two patients with germ cell carcinoma). Carboplatin and ifosfamide appear to have overlapping renal toxicity. Nevertheless, carboplatin and ifosfamide can be combined at 80% and 75% of the single-agent maximum-tolerated doses, respectively, with acceptable nonhematologic toxicity. Ifosfamide and carboplatin are an attractive core combination for further studies in the treatment of sarcoma, germ cell, ovarian, and lung carcinomas.

Adult↗

PubMed1991

A perspective on dose-intensive therapy with autologous bone marrow transplantation for solid tumors.

The poor results seen in patients with advanced solid tumors treated with conventional-dose therapy have stimulated interest in alternative approaches, including higher than standard doses of chemotherapy. Most chemotherapeutic agents exhibit a steep dose-response curve in laboratory models that is log linear in nature. Autologous bone marrow transplantation applies this concept by employing dose-intensive therapy with chemotherapeutic agents whose dose-limiting toxicity is myelosuppression. Alkylating agents are logical choices for high-dose chemotherapy because they have a steep dose-response curve both in vitro and in vivo, and this response is maintained through multiple logs of tumor cell kill. Although at conventional doses myelosuppression is dose-limiting, at transplant doses each agent has its particular dose-limiting organ toxicity which allows alkylating agents to be employed in combination.

Alkylating Agents↗

PubMed1990

Hepatic venoocclusive disease in autologous bone marrow transplantation of solid tumors and lymphomas.

Retrospective review of 291 solid tumor and lymphoma patients undergoing autologous bone marrow transplantation (BMT) was performed to determine the influence of pretransplant characteristics and preparative regimen to the development of hepatic venoocclusive disease (VOD). Twelve patients (4.1%) developed a clinical syndrome of right upper quadrant (RUQ) tenderness or hepatomegaly, jaundice, and ascites, with or without encephalopathy, within 40 days of marrow reinfusion. Evidence of metastatic liver disease was the only pretransplant characteristic predictive for VOD (P = .0002). Sex, age, histology, hepatitis B serology, and elevated liver function tests were not predictive. No individual preparative agent had a significant effect on the development of VOD. However, a single 2-hour infusion of carmustine (BCNU) (greater than or equal to 450 mg/m2) led to an increased incidence of VOD when compared with the same dose administered in a fractionated schedule (P = .0258) when given with two other chemotherapeutic agents. Seven of eight autopsy specimens confirmed the clinical diagnosis of VOD. The four patients in whom clinical VOD resolved had lower median peak bilirubins (7.3 v 15.9 mg/dL), lower median peak creatinines (2.1 v 4.1 mg/dL), and relatively quick engraftment of neutrophils (mean, 18.7 days). One of the four patients in whom VOD resolved had other grade 4 (life-threatening) toxicities in contrast to eight of eight who succumbed. In summary, VOD is an uncommon complication in autotransplantation of solid tumors and lymphomas. Our data suggest caution in selecting patients with known metastatic liver disease and consideration of a fractionated BCNU schedule especially in combination with other alkylating agents.

Adult↗