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Biomedical subjects

Francis Giles

Publications and source records attributed to Francis Giles.

99 records · Page 6Linked to original sources

Quantitative polymerase chain reaction monitoring of BCR-ABL during therapy with imatinib mesylate (STI571; gleevec) in chronic-phase chronic myelogenous leukemia.

PURPOSE: The purpose of our investigation was to evaluate the response and minimal residual disease by quantitative competitive PCR (QC-PCR) studies in patients with chronic myeloid leukemia (CML) treated with imatinib mesylate. EXPERIMENTAL DESIGN: One hundred eighty patients with Philadelphia chromosome (Ph)-positive chronic-phase CML after IFN-alpha failure, treated with imatinib mesylate, had 543 simultaneous cytogenetic and QC-PCR analyses at different times during their therapy. RESULTS: The median QC-PCR values [ratio-percentage of (BCR-ABL/ABL transcripts) x 100] for cytogenetic response categories were: no response (Ph, >90%), 36%; minor response (Ph, 35-90%), 22%; partial response (Ph, 1-34%), 7.3%; complete response (Ph, 0%), 0.89%. There was good correlation between cytogenetic and QC-PCR studies (P < 0.001; r = 0.92) and good concordance between QC-PCR values (>10%, 2-10%, and <2%) and cytogenetic response categories (none, minor, partial, complete) with a concordance rate of 66%, and major discordance of only 10%. Of 170 samples in complete cytogenetic response, 21% still had QC-PCR values of >10%, and 53% had QC-PCR values of <1%. There was excellent concordance between blood and marrow QC-PCR values (r = 0.965; P < 0.01; concordance rate, 88%; major discordance, 0%). No patient in complete cytogenetic response regardless of QC-PCR value has yet relapsed. At a median follow-up time of 26 months, higher QC-PCR values within each cytogenetic category at 3, 6, and 9 months have not been associated with a higher occurrence cytogenetic relapse or disease progression. However, the significance of this may become different with longer follow-up. CONCLUSION: QC-PCR studies provide a useful tool to monitor patients with CML on imatinib mesylate therapy.

Antineoplastic Agents↗

Efficacy of the farnesyl transferase inhibitor R115777 in chronic myeloid leukemia and other hematologic malignancies.

We investigated the clinical activity of the farnesyl transferase inhibitor R115777 in 22 patients with chronic myelogenous leukemia (CML) in chronic, accelerated, or blastic phase and in 8 patients with myelofibrosis (MF) and 10 patients with multiple myeloma (MM). R115777 was administered at 600 mg orally twice daily for 4 weeks every 6 weeks. Seven patients with CML (6 in chronic phase, 1 in advanced phase) achieved complete or partial hematologic response. Four of them had a minor cytogenetic response. Responses were transient, with a median duration of 9 weeks (range, 3-23 weeks). Two patients discontinued therapy because of toxicity while in complete hematologic response. Two MF patients had a significant decrease in splenomegaly, one had normalization of white blood cell count and differential, and one became transfusion independent. One patient with MM had a reduction in monoclonal protein of 34%. Adverse events included nausea in 22 patients (55%; all grade 2 or lower) and fatigue in 19 (48%; grade 3 or higher in 1). Other grade 3 or 4 toxicities included skin rash (4 patients, 10%), peripheral neuropathy (2 patients, 5%), and liver toxicity (2 patients, 5%). Patients who responded to therapy had significantly higher plasma vascular endothelial growth factor (VEGF) concentrations prior to treatment than nonresponders. Plasma concentrations decreased significantly during therapy among responders. R115777 showed clinical activity in patients with CML and MF. The effect on VEGF needs to be further investigated to determine whether this might be a possible mechanism of action of R115777.

Adult↗

Dose escalation of imatinib mesylate can overcome resistance to standard-dose therapy in patients with chronic myelogenous leukemia.

We investigated whether increasing the dose of imatinib mesylate might overcome drug resistance in patients with Philadelphia chromosome-positive (Ph(+)) chronic myelogenous leukemia (CML) whose disease manifests relapse or refractoriness to therapy. Fifty-four patients with Ph(+) CML in chronic phase and with hematologic or cytogenetic resistance or relapse on imatinib mesylate therapy at 400 mg orally daily were treated with a higher dose of 400 mg orally twice daily (800 mg daily, 47 patients; or 600 mg daily increased from 300 mg daily, 7 patients). Among 20 patients treated for hematologic resistance or relapse, 13 (65%) achieved a complete (n = 9) or partial (n = 4) hematologic response, but only 1 had a cytogenetic partial response (Ph reduction from 100% to 10%) and 1 had a minor response (Ph reduction from 100% to 50%). Among 34 patients treated for cytogenetic resistance or relapse, 19 (56%) achieved a complete (n = 6) or partial (n = 7) cytogenetic response. We conclude that higher doses of imatinib mesylate may overcome disease-poor response to conventional doses and that this approach deserves further evaluation as frontline therapy for newly diagnosed CML.

Adult↗

Imatinib mesylate therapy in newly diagnosed patients with Philadelphia chromosome-positive chronic myelogenous leukemia: high incidence of early complete and major cytogenetic responses.

Fifty patients with Philadelphia chromosome-positive (Ph(+)) chronic myelogenous leukemia (CML) in early chronic phase received imatinib mesylate, 400 mg orally daily. After a median follow-up of 9 months, 49 patients (98%) achieved a complete hematologic response and 45 patients (90%) achieved a major cytogenetic response, complete in 36 patients (72%). Compared with similar patients who received interferon-alpha with or without hydroxyurea or other interferon-alpha combination regimens, those receiving imatinib mesylate had higher incidences of complete and major (Ph < 35%) cytogenetic responses at 3 months (34% and 74% versus 1%-4% and 9%-24%, respectively), 6 months (52% and 80% versus 3%-7% and 11%-28%, respectively), and 9 months (60% and 77% versus 5%-11% and 14%-30%, respectively; P <.001). Competitive quantitative polymerase chain reaction (QPCR) studies at 9 months showed a median QPCR value (ratio of BCR-ABL/ABL transcripts x 100) of 0.59% overall and of 0.24% (range, 0.001%-29.5%) for complete cytogenetic response.

Adolescent↗

Recombinant human soluble tumor necrosis factor (TNF) receptor (p75) fusion protein Enbrel in patients with refractory hematologic malignancies.

PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) is an important effector and regulatory cytokine involved in the pathophysiology of hematologic malignancies, including hairy cell leukemia (HCL), chronic lymphocytic leukemia (CLL), agnogenic myeloid metaplasia (AMM) and Philadelphia-negative myeloproliferative disorders (MPD). We conducted a pilot study to assess the safety of the soluble TNF receptor, etanercept (p75 TNFR:Fc; Enbrel) in patients with refractory hematologic malignancies. METHODS: Patients were eligible if they had refractory HCL, CLL, AMM, or Philadelphia-negative MPD. Enbrel was administered twice weekly at a dose of 25 mg subcutaneously for a minimum of eight doses, and was continued in patients without overt progression. RESULTS: Among the 26 patients enrolled on study, 25 patients were evaluable. Nine patients had AMM, eight CLL, three HCL, and five Philadelphia-negative MPD. Their median age was 60 years (range 30-83 years). A total of 70 courses consisting of 486 doses of Enbrel were administered. Enbrel was well tolerated, without any overt increase in infectious episodes. Stable disease/no objective response was seen in 22 patients (88%) and progression in 3 patients (12%). Three patients with AMM improved (two showed hematologic improvement, and one showed a reduction in liver and spleen size), and two patients (one with CLL and one with Philadelphia-negative MPD) showed improvement in disease-related symptoms. CONCLUSIONS: Enbrel was well tolerated, but no responses were noted in these immunosuppressed patients with refractory hematologic malignancies.

Adult↗

Differences in CD33 intensity between various myeloid neoplasms.

We measured the concentration of CD33 antigen on the surface of cells in 315 bone marrow (BM) samples and 114 corresponding peripheral blood (PB) samples from patients with various leukemias (acute myeloid leukemia [AML], chronic myelogenous leukemia [CML], myeloproliferative disorder [MPD] other than CML, myelodysplastic syndrome [MDS]) and from control subjects. Overall CD33 intensity in total CD33+ cells was significantly higher in BM than in PB. CD33 intensity in total BM CD33+ cells differed significantly with the type of disease. The median number of CD33 molecules per cell was highest in AML, followed by MDS, CML, and control subjects and lowest in MPD. When only CD34+/CD33+ cells were examined, CD33 molecules per cell were highest in CD34+ cells in AML and lowest in MPD (P = .027). Patients with AML or MDS younger than 60 years had significantly higher intensity of CD33 expression on CD34+ cells than patients 60 years or older. Levels of CD33 intensity did not correlate with cytogenetics in patients with AML or MDS. There was no correlation between CD33 intensity and response to therapy or overall survival in 35 patients treated with protocols including Mylotarg. These data demonstrate variation in CD33 intensity between various leukemias.

Aminoglycosides↗

A phase I study of idarubicin dose escalation with amisfostine and high-dose cytarabine in patients with relapsed acute myelogenous leukemia and myelodysplastic syndromes.

BACKGROUND AND OBJECTIVES: Early studies have suggested that increasing doses of anthracycline improve outcome in younger patients with acute myelogenous leukemia (AML), but dose escalation has been precluded by the acute and chronic toxicities of these agents. Amifostine is a cytoprotective compound that has been shown to protect against the acute cytotoxicities of anthracyclines in animal models. We report the results of a phase I study of dose escalation of idarubicin with amifostine and high-dose ara-C in patients with relapsed or refractory AML or myelodysplastic syndrome (MDS). DESIGN AND METHODS: The continuous reassessment method was used to predict the probability of toxicity. RESULTS: Five patients were treated at an idarubicin dose of 18 mg/m2/day x 3, three of whom developed grade 3 diarrhea or mucositis. Subsequently, three additional patients were treated at a dose of 15 mg/m2 x 3 days, all of whom experienced grade 3 diarrhea or mucositis. One patient achieved complete remission (CR rate 12.5%, 95% CI 0-0.52%). INTERPRETATION AND CONCLUSIONS: The addition of amifostine does not allow dose escalation of idarubicin when combined with high-dose ara-C.

Adult↗