Drug cross-resistance and therapy-induced resistance in chronic lymphocytic leukaemia by an enhanced method of individualised tumour response testing.

Previous results with individualised tumour response testing (ITRT) in vitro in chronic lymphocytic leukaemia (CLL) have consistently shown good correlation with patient response and survival. We describe here an improved test and report its use with samples from the Leukaemia Research Fund CLL4 randomised clinical trial and previously treated patients. ITRT was performed by the tumour response to anti-neoplastic compounds (TRAC) assay, a modification of the differential staining cytotoxicity (DiSC) assay. Improvements included drying drugs into wells before assay and using the Octospot system to cytocentrifuge eight spots of cells onto one microscope slide. We successfully tested 765/782 (98%) cellular blood samples received within 48 h of phlebotomy. Cross-resistance (Pearson's r > 0.7) in untreated CLL was found between similar drugs. Mitoxantrone (r = 0.31), cyclophosphamide (r = 0.35) and pentostatin (r = 0.29) had low cross-resistance with fludarabine. Treatment resulted in increased resistance to chlorambucil, cyclophosphamide, doxorubicin, mitoxantrone, corticosteroids, cladribine and fludarabine (P < 0.01) but not to pentostatin. These results provide further rationale for standard drug combinations such as fludarabine-mitoxantrone and fludarabine-mitoxantrone-cyclophosphamide and suggest possible pentostatin salvage in fludarabine-resistant patients. ITRT results could assist both in determining the best treatment for individual patients and in the design and rationale of future clinical trials.

Eradication of minimal residual disease in B-cell chronic lymphocytic leukemia after alemtuzumab therapy is associated with prolonged survival.

PURPOSE: To test whether eradication of minimal residual disease (MRD) in B-cell chronic lymphocytic leukemia (CLL) by alemtuzumab is associated with a prolongation of treatment-free and overall survival. PATIENTS AND METHODS: Ninety-one previously treated patients with CLL (74 men and 17 women; median age, 58 years [range, 32 to 75 years]; 44 were refractory to purine analogs) received a median of 9 weeks of alemtuzumab treatment between 1996 and 2003. Regular bone marrow assessments by MRD flow cytometry were performed with the aim of eradicating detectable MRD (< 1 CLL cell in 10(5) normal cells). RESULTS: Responses according to National Cancer Institute-sponsored working group response criteria were complete remission (CR) in 32 patients (36%), partial remission (PR) in 17 patients (19%), and no response (NR) in 42 patients (46%). Twenty-two (50%) of 44 purine analog-refractory patients responded to alemtuzumab. Detectable CLL was eradicated from the blood and marrow in 18 patients (20%). Median survival was significantly longer in MRD-negative patients compared with those achieving an MRD-positive CR, PR, or NR. Patients achieving an MRD-negative CR had a longer treatment-free survival than patients with MRD-positive CRs, PR, or NR: MRD-negative CRs, not reached; MRD-positive CRs, 20 months; PRs, 13 months; NR, 6 months (P < .0001). Overall survival for the 18 patients with MRD-negative remissions was 84% at 60 months. Eight (47%) of the MRD-negative patients converted to MRD positivity at a median of 28 months. CONCLUSION: MRD-negative remission in CLL is achievable with alemtuzumab, leading to an improved overall and treatment-free survival.

Thalidomide is highly effective in a patient with meningeal acute myeloid leukaemia.

We report a case of secondary acute myeloid leukaemia (AML) following high dose therapy for diffuse large B-cell non-Hodgkin's lymphoma (NHL) who developed meningeal leukaemia. This was refractory to systemic and intrathecal chemotherapy and cranial irradiation. Thalidomide has been reported to have anti-AML activity and appears to cross the blood brain barrier (BBB). We, therefore, attempted a trial of oral Thalidomide and achieved rapid biochemical and cytological remission with a short course. The patient, however, progressed systemically and succumbed to her illness.

Thromboembolism in patients on thalidomide for myeloma.

Seven cases of thromboembolism were found amongst 23 patients treated with thalidomide for myeloma over a total of 141.5 patient treatment months. Five thromboembolic events were venous (two severe) and two arterial. A historical control of 18 similar patients not given thalidomide had one thromboembolism over 289 months. We found no underlying thrombophilic tendency in the affected patients. We suggest that the thalidomide may predispose to thromboembolism at even lower doses than previously reported (mean dose 150 mg). The two most severe thromboses occurred on 100 mg thalidomide alone, not associated with chemotherapy or glucocorticoids. We raise the possibility that arterial thromboembolism may also occur in association with thalidomide. Some patients continued thalidomide after the event, together with warfarin, with no further thromboembolism.

Spontaneous remission of low-grade B-cell non-Hodgkin's lymphoma following withdrawal of methotrexate in a patient with rheumatoid arthritis: case report and review of the literature.

A 69-year-old woman, who had suffered from deforming rheumatoid arthritis since the age of 40 years, had been treated with methotrexate for 3 years. She presented with a 7 week history of neck lymphadenopathy. Biopsy revealed low-grade marginal-zone B-cell non-Hodgkin's lymphoma. Computerized tomography and bone marrow biopsy confirmed stage IIIA disease. Spontaneous complete remission of the lymphoma was achieved 14 months after withdrawing immune suppression with methotrexate.