BioOncology Watch

Timely Information for Practicing Physicians

 

MAY 1999

METASTATIC MELANOMA
Autologous melanoma vaccine. Stanley Leong and colleagues treated 20 stage IV melanoma patients with multiple cycles of an autologous melanoma vaccine combined with an adjuvant injection of BCG plus rhGM-CSF. Two patients had a CR and two patients had a PR with regression of visceral and paraaortic masses. These objective responses demonstrate that melanoma patients with large tumor burdens can respond to specific immunotherapy. (Leong SPL, et al. J Immunother 1999; 22: 166-174)

MULTIPLE MYELOMA
Cytokine-based tumor cell vaccine. Alexander Shtil and associates generated potent granzyme B/ perforin-secreting (pore-forming) CTLs by immunizing mice with MPC11 cells (a murine myeloma model) expressing GM-CSF and IL-12 or with MPC11 multidrug-resistant (MDR) variant cell lines transfected with GM-CSF/IL-12. Immunization caused rejection of both transplanted MPC11 cells and the MDR sublines in Balb/c mice even though these myeloma cells were resistant to APO-1/CD95/Fas ligand. These data indicate that MDR mediated by mdr1/Pgp did not prevent lysis by pore-forming CTLs and that this immunotherapy may be a therapeutic approach for drug-resistant myeloma. (Shtil AA, et al. Blood 1999; 93: 1831-1837)

LEUKEMIA
Immunotherapy with ex vivo-generated cytotoxic T lymphocytes (CTLs). Tuna Mutis and coworkers have reproducibly generated CTLs specific for the hematopoietic cell-restricted minor histocompatibility antigens (mHags) HA-1 and HA-2 from HA-1 and/or HA-2-negative healthy blood donors using dendritic cells pulsed with HA-1 and HA-2 synthetic peptides. These ex-vivo generated CTLs were found to efficiently lyse leukemia cells (from AML and ALL patients) while nonhematopoietic cells were unharmed. This study indicates that ex-vivo-generated CTLs specific for hematopoietic mHags are a feasible therapy for relapsed leukemia after allogeneic bone marrow transplantation and that this therapy has a low risk of GVHD. (Mutis T, et al. Blood 1999; 93: 2336-2341)

GRAFT VS. TUMOR (GVT) INDUCTION
Donor leukocyte infusions (DLIs) as primary therapy. David Porter and associates treated 18 patients with both hematologic and solid tumor malignancies with HLA-matched DLIs. Interferon alfa-2b was administered to patients for a minimum of 4 weeks prior to DLI therapy and patients without toxicity or donor leukocyte engraftment were eligible to receive cytarabine or cyclophosphamide followed by a second course of DLI treatments. In heavily pretreated patients, this allogeneic adoptive immunotherapy caused a sustained chimerism, acute GVHD, and a graft-vs.-tumor (GVT) response to occur which suggests that allogeneic donor cell engraftment is necessary to induce a GVT reaction. (Porter DL, et al. J Clin Oncol 1999; 17: 1234-1243)

CHRONIC LYMPHOCYTIC LEUKEMIA (CLL)
CD40 activation of CLL-B-cells. Raymund Buhmann and colleagues induced B-CLL cells to become efficient antigen-presenting cells by obtaining B-CLL cells from the peripheral blood of CLL patients (CD40 was detectable in all B-CLLs) and culturing them on CD40L expressing feeder cells. Stimulation of allogeneic T-cells with these CD40-activated B-CLL cells resulted in the expansion of a specific CD8+ CTL population while stimulation of autologous T cells resulted in the expansion of CD4+ T-cell population that released interferon-g in response to the CD40-CLL cells. These findings may be supportive of future immunotherapeutic approaches to B-CLL. (Buhmann R, et al. Blood 1999; 93: 1992-2002)

NON-HODGKIN'S LYMPHOMAS (NHL)
Response criteria. Bruce Cheson and coworkers proposed standardized guidelines for response criteria for NHL clinical trials developed during two meetings convened by international lymphoma experts. The criteria include definitions of response and normal lymph node size after treatment and a designation of a "complete response/unconfirmed" category. In addition, with appropriate expertise the use of single-photon emission computed tomography gallium scans are encouraged as a valuable adjunct. It is anticipated that these guidelines will improve communication and comparability among clinical trials. (Cheson BD, et al. J Clin Oncol 1999; 17: 1244-1253)

LUNG CANCER
NY-ESO-1 expression
. Li Lee et al recently detected NY-ESO-1 expression, a gene in the class of cancer-testis antigens, in 11 of 16 small cell lung cancer cell lines and 3 of 7 NSCLC cell lines by reverse transcriptase and PCR amplification techniques. They also found that lung cancer cells expressing NY-ESO-1 are recognized by an HLA-restricted cytotoxic T-cell clone and that NY-ESO-1 expression is induced by the demethylating agent, 5-aza-2¢-deoxycytidine. These results suggest that NY-ESO-1 may be a potential target for lung cancer immunotherapy. (Lee L, et al. Cancer J Sci Am 1999; 5: 20-25)

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