Georgia Schilling

Post-transplant immunotherapy with donor-lymphocyte infusion and novel agents to upgrade partial into complete and molecular remission in allografted patients with multiple myeloma.

OBJECTIVE To investigate post-transplant immunotherapy with escalating donor-lymphocyte infusions (DLI) and novel agents (thalidomide, bortezomib, and lenalidomide) to target complete remission (CR). MATERIALS AND METHODS Thirty-two patients with multiple myeloma who achieved only partial remission after allogeneic stem cell transplantation were treated with DLI. If no CR was achieved, one of the novel agents was added to target CR. RESULTS CR defined either by European Group for Blood and Marrow Transplantation criteria, flow cytometry, or molecular methods as assessed by patient-specific immunoglobulin H-polymerase chain reaction or plasma cell chimerism polymerase chain reaction was accomplished in 59%, 63%, and 50% of patients, respectively. Achievement of CR resulted in improved 5-year progressive-free and overall survival, according to European Group for Blood and Marrow Transplantation criteria (53% vs 35%; p=0.03 and 90% vs 62%; p=0.06), flow cytometry (74% vs 15%; p=0.001 and 100% vs 52%; p=0.1), or molecular methods (84% vs 38%; p=0.001 and 100% vs 71%; p=0.03). CONCLUSIONS Our finding demonstrates the clinical relevance of posttransplantation therapies to upgrade remission, and of remissions depth for long-term survival in myeloma patients.

Lenalidomide as salvage therapy after allo-SCT for multiple myeloma is effective and leads to an increase of activated NK (NKp44(+)) and T (HLA-DR(+)) cells.

We investigated efficacy and toxicity of lenalidomide in 24 heavily pretreated myeloma patients with a median age of 59 years (range: 37–70) and relapse after allo-SCT. Lenalidomide was given at a dose of 15 mg (n=4), or 25 mg (n=20), orally once daily on day 1 to day 1 every 28 days, with (n=20) or without (n=4) DHAP. The median number of lenalidomide cycles was five (range: 2–17). Major side effects were leukopenia (grade 4: 4%, grade 3: 21% and grade 2: 17%) and thrombocytopenia (grade 3: 17% and grade 2: 29%); infectious complications were observed in 50%. Non-hematological toxicity consisted of muscle cramps (n=9), fatigue (n=5) and constipation (n=2). Mild grade I–II GVHD was seen in three patients. Response was achieved in 66%: CR in 8%, VGPR in 8%, PR in 50% and SD in 13%. The median time to progression was 9.7 months (95% confidence interval (CI): 7.5–11.9), and median OS was 19.9 months (95% CI: 17.3–22.5). Immunomonitoring after lenalidomide showed significant increase of activated NK (NKp44+) and T (HLA-DR+) cells, as well as regulatory T cells (CD4+, CD25+, CD127lo), supporting an immunomodulating anti-myeloma effect of lenalidomide.

Impact of genetic abnormalities on survival after allogeneic hematopoietic stem cell transplantation in multiple myeloma

We analyzed the prognostic impact of the most frequent genetic abnormalities detected by fluorescence in situ hybridization in 101 patients with multiple myeloma, who underwent allogeneic hematopoietic stem cell transplantation (HSCT) after melphalan/fludarabine-based reduced conditioning. The incidences of abnormalities in the present analysis were as follows: del(13q14) (61%), t(11;14)(q13;q32) (14%), t(4;14)(p16.3;q32) (19%), MYC-gain gains (8q24) (21%), del(17p13) (16%) and t(14;16)(q32;q23) (5%). None of the patients had t(6;14)(p25;q32). The overall complete remission (CR) rate was 50% with no differences between the genetic abnormalities except for patients with del(17p13) who achieved less CR (7 vs 56%; P=0.001). Univariate analysis revealed a higher relapse rate in patients aged >50 years (P=0.002), patients with del(13q14) (P=0.006) and patients with del(17p13) (P=0.003). In multivariate analyses, only del(13q14) (HR: 2.34, P=0.03) and del(17p13) (HR: 2.24; P=0.04) significantly influenced the incidence of relapse, whereas for event-free survival, only age (HR 2.8; P=0.01) and del(17p13) (HR: 2.05; P=0.03) retained their negative prognostic value. These data show that del(17p13) is a negative prognostic factor for achieving CR as well as for event-free survival after HSCT. Translocation t(4;14) might be overcome by allogeneic HSCT, which will have implication for risk-adapted strategies.

Cancer-testis antigen expression and its epigenetic modulation in acute myeloid leukemia†

Cancer‐testis antigens (CTA) represent attractive targets for tumor immunotherapy. However, a broad picture of CTA expression in acute myeloid leukemia (AML) is missing. CTA expression was analyzed in normal bone marrow (BM) as well as in AML cell lines before and after treatment with demethylating agents and/or histone acetylase inhibitors. Presence of selected CTA with a strictly tumor‐restricted expression was then determined in samples of patients with AML before and after demethylating therapy. Screening AML cell lines for the expression of 20 CTA, we identified six genes (MAGE‐A3, PRAME, ROPN1, SCP‐1, SLLP1, and SPO11) with an AML‐restricted expression. Analyzing the expression of these CTA in blast‐containing samples from AML patients (N = 64), we found all samples to be negative for MAGE‐A3 and SPO11 while a minority of patients expressed ROPN1 (1.6%), SCP‐1 (3.1%), or SLLP1 (9.4%). The only CTA expressed in substantial proportion of patients (53.1%) was PRAME. Following demethylating treatment with 5′‐aza‐2′‐deoxycytidine, we observed an increased or de novo expression of CTA, in particular of SSX‐2, in AML cell lines. In AML patients, we detected increased expression of PRAME and induction of SSX‐2 after demethylating therapy with 5‐azacytidine. With the exception of PRAME, CTA are mostly absent from AML blasts. However, demethylating treatment induces strong expression of CTA, particularly of SSX‐2, in vitro and in vivo. Therefore, we propose that CTA‐specific immunotherapy for AML should preferentially target PRAME and/or should be combined with the application of demethylating agents opening the perspective for alternative targets like CTA SSX‐2. Am. J. Hematol., 2011.

Unrelated stem cell transplantation after reduced intensity conditioning for patients with multiple myeloma relapsing after autologous transplantation.

From 2002 to 2007, 49 myeloma patients who relapsed following autologous SCT were included in a prospective multicenter trial to determine the efficacy of a reduced melphalan/fludarabine regimen followed by allogeneic SCT from unrelated donors. All patients showed leucocyte and platelet engraftment after a median of 15 and 19 d, respectively. Grade II–IV acute graft‐versus‐host disease (GvHD) occurred in 25% of patients and 35% had chronic GvHD. Overall response rate at day 100 was 95% including 46% complete remission (CR). Cumulative incidence of non‐relapse mortality at 1 year was 25% [95% confidence interval (CI): 13–37%] and was significantly lower for human leucocyte antigen (HLA)‐matched compared to ‐mismatched SCT (10% vs. 53%, P = 0·001). The cumulative incidence of relapse at 3 years was 55% (95% CI: 40–70%). After a median follow up of 43 months, the estimated 5‐year progression‐free and overall survival rates were 20% and 26% respectively and were significantly better for matched in CR at day 100 (41% vs. 7%, P = 0·04 and 56% vs. 16%, P = 0·02). We conclude that optimal donor selection is mandatory for a low non‐relapse mortality and high relapse incidence, which remains a major concern, should be improved by including post‐transplant strategies to upgrade remission status.

Cytogenetics of extramedullary manifestations in multiple myeloma

Extramedullary disease in patients with multiple myeloma is a rare event, occurring mostly in advanced disease or relapse. Outcome is poor and prognostic factors predicting the development of extramedullary disease have not been defined. We investigated cytogenetic alterations of myeloma cells in different extramedullary manifestations by adapting the fluorescence in situ hybridization (FISH) technique in combination with cytoplasmic immunoglobulin staining to study the cytogenetics of plasma cell tumours on paraffin embedded material. Thirty six patients were investigated: 19 with extramedullary disease, 11 with skeletal extramedullary disease and six with solitary extramedullary plasmacytoma. The first two groups showed the following results: del(17p13) 32% vs. 27%, del(13q14) 35% vs. 27%, MYC‐overrepresentation 28% vs. 18% and t(4;14) 37% vs. 18%. We detected an overall higher incidence of del(17p13) in both groups compared to data from bone marrow samples of multiple myeloma reported to date (range 7–16%). The solitary extramedullary plasmacytomas presented overall less cytogenetic aberrations than the other groups. Most important, three patients with extramedullary disease and one with skeletal extramedullary disease presented different FISH findings in the extramedullary tumour compared to their bone marrow plasma cells. del(17p13), occurring additional in three of four cases, seems a strong marker for extramedullary progression of myeloma.

Second autologous transplant as salvage therapy in multiple myeloma

High‐dose chemotherapy followed by autologous haematopoetic stem cell transplantation (ASCT) is a standard frontline therapy for multiple myeloma (MM). Unfortunately, there are no randomized clinical studies examining the role of a second ASCT in patients who relapse after the initial autotransplant. Analysing all available retrospective studies, it seems that salvage ASCT can safely be performed in most patients with an overall treatment‐related mortality rate <5%. Approximately 65% of patients will achieve an objective response and progression‐free and overall survival will be around 12 months and 32 months, respectively. Retrospective data suggest that patients with a progression‐free survival of ≥18 months after initial ASCT are most likely to benefit from a salvage autotransplant. However, patients with a <12‐month duration of response after initial ASCT should not be considered for a second autograft in the relapsed setting because this group will probably only experience ASCT‐related toxicity without any clinical benefit. Quality of response after initial ASCT and number of therapies preceding salvage ASCT may also have a predictive value. Importantly, these findings need to be verified by randomized clinical trials in order to firmly integrate salvage ASCT into a global therapeutic concept for myeloma patients including optimized induction, consolidation, and maintenance approaches.

A novel cryptic translocation t(12;17)(p13;p12-p13) in a secondary acute myeloid leukemia results in a fusion of the ETV6 gene and the antisense strand of the PER1 gene

The ETV6 gene is a member of the ETS family of transcription factors and the main target of chromosomal rearrangements affecting chromosome band 12p13. To date, more than 15 fusion partners of ETV6 have been characterized at the molecular level. Most of these fusions encode chimeric proteins with oncogenic properties. However, some of the translocations do not produce a functional fusion protein, but may induce ectopic expression of oncogenes located close to the breakpoint. We herein report the characterization and cloning of a novel cryptic translocation, t(12;17)(p13;p12–p13), occurring in a patient with an acute myeloid leukemia evolving from a chronic myelomonocytic leukemia. Cytogenetic analysis suggested the presence of a deletion of the short arm of chromosome 12, del(12)(p13), in three of the five metaphase cells analyzed. However, fluorescence in situ hybridization (FISH) with the ETV6‐specific cosmid clones 179A6, 50F4, 163E7, and 148B6 as well as probes hybridizing to the TP53 gene on 17p13 and the subtelomeric region of 17p revealed the presence of a translocation between 12p and 17p. By FISH, the breakpoints could be localized in intron 1 of ETV6 and centromeric to TP53. By 3′ rapid amplification of cDNA ends–polymerase chain reaction (3′ RACE‐PCR), a fusion transcript between exon 1 of ETV6 and the antisense strand of PER1 (period homolog 1, Drosophila), a circadian clock gene, could be identified. This ETV6‐PER1 (antisense PER1 strand) fusion transcript does not produce a fusion protein, and no other fusion transcripts could be detected. We hypothesize that in the absence of a fusion protein, the inactivation of PER1 or deregulation of a gene in the neighborhood of PER1 may contribute to the pathogenesis of leukemias with a t(12;17)(p13;p12–p13).

Toxicity-reduced, myeloablative allograft followed by lenalidomide maintenance as salvage therapy for refractory/relapsed myeloma patients

Relapse after dose-reduced allograft in advanced myeloma patients remains high. To reduce the risk of relapse, we investigated a myeloablative toxicity-reduced allograft (aSCT) consisting of i.v. BU and CY followed by lenalidomide maintenance therapy in 33 patients with multiple myeloma (MM) who relapsed following an autograft after a median of 12 months. The cumulative incidence of non-relapse mortality at 1 year was 6% (95% confidence interval (CI): 0–14). After a median interval of 168 days following aSCT, 24 patients started with a median dose of 5 mg (r, 5–15) lenalidomide without dexamethasone. During follow-up, 13 patients discontinued lenalidomide owing to progressive disease (n=6), GvHD (n=3), thrombocytopenia (n=2), or fatigue (n=2). Major toxicities of lenalidomide were GvHD II–III (28%), viral reactivation (16%), thrombocytopenia (III–IV°,16%), neutropenia (III/IV°, 8%), peripheral neuropathy (I/II°, 16%), or other infectious complication (8%). Cumulative incidence of relapse at 3 years was 42% (95% CI: 18–66). The 3-year estimated probability of PFS and OS was 52% (95% CI: 28–76) and 79% (95% CI: 63–95), respectively. Toxicity-reduced myeloablative allograft followed by lenalidomide maintenance is feasible and effective in relapsed patients with MM, but the induction of GvHD should be considered.

Expression and prognostic relevance of MAGE-C1/CT7 and MAGE-C2/CT10 in osteolytic lesions of patients with multiple myeloma

Cancer-testis (CT) antigens are promising targets for antigen-specific therapy of multiple myeloma (MM). Osteolytic lesions represent the most common clinical manifestation of myeloma and it is possible that osseous myeloma lesions differ from bone-infiltrating tumor cells with regard to the extent of CT antigen expression based on the epigenetic regulation of these genes. We, therefore, performed the first analysis of CT antigen expression in osteolytic lesions of myeloma patients to further define the diagnostic, prognostic, and therapeutic value of these proteins. Lytic bone samples were obtained from MM patients during surgical interventions and a tissue microarray was constructed. 105 bone samples and 24 bone marrow biopsies were stained immunohistochemically with antibodies against CT antigens MAGE-C1/CT7 and MAGE-C2/CT10 and Ki-67. MAGE-C1/CT7 and MAGE-C2/CT10 were frequently expressed in osteolytic lesions (46% and 54%) and bone marrow (75% and 54%). Expression of MAGE-C1/CT7 was significantly more frequent in patients with advanced stage of disease (p=0.023) and with a chromosomal deletion 17p13 (p53) (p=0.047). Samples with more than 75% MAGE-C1/CT7 expressing myeloma cells showed a higher proliferative rate (indicated by the expression of Ki67) than those with less than 25% MAGE-C1/CT7 expressing cells (p=0.011). Moreover, a content of ≥50% MAGE-C1/CT7 expressing myeloma cells in a sample was associated with reduced overall survival (p=0.013). Our results, therefore, suggest that expression of MAGE-C1/CT7 and MAGE-C2/CT10 in osteolytic lesions of myeloma patients can be used for diagnostic, prognostic, as well as immunotherapeutic purposes.