Autologous stem cell transplants in lymphomas

Stem cell transplantation in multiple myeloma: impact of response failure with thalidomide or lenalidomide induction

Autologous stem cell transplantation as a platform for multiple myeloma treatment is the standard of care for patients who can safely withstand the procedure. Before novel agents were introduced, one-third to one-half of patients did not achieve partial response at transplantation. Previous medical literature has shown that in this past era, absence of initial response to induction therapy had no impact on progression-free survival and overall survival after high-dose therapy. Lack of response to initial induction did not preclude a good response after stem cell transplantation. With the introduction of novel agents-immunomodulatory drugs and proteasome inhibitors-response rates with initial therapy are now between 70% and 100%. This retrospective study analyzes progression-free survival and overall survival in patients who do not have a partial response (never responded or progressed during continuous therapy) after induction therapy with a regimen that contains thalidomide or lenalidomide. Unlike patients in reports published previously-before immunomodulatory drugs-patients who do not achieve partial remission have a significantly shorter overall survival from transplantation (73.5 vs 30.4 months) and a shorter progression-free survival (22.1 vs 13.1 months; P < .001). Absence of a response to induction therapy with thalidomide or lenalidomide predicts a poorer outcome after high-dose therapy.

The use of Shiga-like toxin 1 in cancer therapy

The ribosome-inactivating protein, Shiga-like toxin-1 (SLT-1, SLT-I, Verotoxin 1, VT1) targets cells that express the glycolipid globotriaosylceramide (CD77) on their surface. The frequent occurrence of SLT-1 receptors on tumor cells derived from patients with hematological cancers (follicular lymphoma, multiple myeloma, chronic lymphocytic leukemia) and their absence on human CD34(+) hematopoietic stem cells suggest the ex vivo use of Shiga-like toxin-1 in purging CD77(+) tumor cells from autologous stem cell transplants. SLT-1 receptors are also commonly expressed on breast cancer, ovarian cancer and astrocytoma cells. In particular, the sensitivity of astrocytoma cell lines to this toxin provides an opportunity for using SLT-1 in vivo in the context of treating patients afflicted by this common form of brain tumor. Finally, the known structural features of SLT-1 allow one to contemplate altering its receptor specificity in an effort to target CD77(-) tumor cell populations.

Cardiac and pulmonary toxicity in patients undergoing high-dose chemotherapy for lymphoma and breast cancer: prognostic factors

We sought to define risk factors predisposing breast cancer and lymphoma patients to cardiac and pulmonary toxicity when undergoing high-dose chemotherapy (HDC) and autologous stem cell rescue (ASCR). Additionally, we evaluated in depth the predictive value of the ejection fraction measured prior to HDC in determining cardiac toxicity. In this retrospective analysis, 24 variables were examined in 138 patients undergoing HDC and ASCR from 1990 until 1995. Logistic regression models were used to model the probability of experiencing cardiac and pulmonary toxicity as a function of the 24 prognostic covariates. Cardiac toxicity occurred in 12% of patients and pulmonary toxicity in 24% of patients. Bivariate analyses showed that patients with lymphoma (as opposed to breast cancer) and those with a higher cardiac risk factor score were more likely to experience cardiac toxicity. Multivariate logistic regression models predicted lymphoma and older age to be risk factors for cardiac toxicity. History of an abnormal ejection fraction and higher doses of anthracyclines prior to HDC may also contribute to cardiac toxicity. Pulmonary toxicity occurred more commonly in lymphoma than breast cancer patients, likely due to the busulfan used in the HDC regimen. No other risk factors for pulmonary toxicity were identified. We conclude that older patients with lymphoma should be carefully evaluated prior to being accepted for HDC programs. Older patients with breast cancer may tolerate this procedure well. There is a trend towards cardiac toxicity in patients with a past history of low ejection fraction, although seemingly poor cardiac risk patients may fare well with HDC if carefully selected with the aid of a thorough cardiac evaluation.

CD34+ cell engraftment, ex vivo expansion, and malignant cell depletion following immunomagnetic selection

This review describes the published preclinical and clinical data on the use of a manual or semiautomated immunomagnetic selection device, termed the Isolex system. Preclinical evaluation of hematopoietic progenitor cells (CD34+ cells) selected from bone marrow, peripheral blood leukapheresis products, and umbilical cord blood is reviewed with respect to differentiation (CFU-GM, BFU-E, and CFU-GEMM formation) and proliferation. The purities and yields of CD34+ cell products from clinical trials performed since 1994 are presented along with data on malignant cell depletion. On average, the Isolex system resulted in a final product median purity of 67% and a final product median yield of 64%. Positive selection of CD34+ cells with this device decreased residual tumor cell levels by 2-3 logs in autologous transplant products and reduced T cell levels by 3-4 logs in allogeneic grafts. To evaluate the clinical effect of these immunomagnetically selected cells, data on the rate of engraftment were reviewed. Autologous CD34+ cell transplantation resulted in recovery time from neutropenia (ANC > 500/microliter) of 9-14 days and recovery time from thrombocytopenia (platelet count > 20,000/microliter) of 10-20 days. These data showed that the Isolex system can positively select progenitor cells to reconstitute the hematopoietic system following myeloablative therapy.