[The molecular pathogenesis of classical Hodgkin lymphoma]

Despite the fact that classical Hodgkin lymphoma (HL) has been described more than 170 years ago, only over the last 15 years significant advances regarding its molecular pathogenesis have been achieved. The lack of a specific lineage profile in combination with the low number of the malignant mononuclear Hodgkin- and multinucleated Reed-Sternberg- (HRS-) cells in the affected lymph nodes prevented for a long time both the identification of its cell of origin and of genomic and molecular defects. The development of methods for the analysis of micromanipulated single cells made it possible to demonstrate a B cell origin of HRS cells. However, it has become clear that the normal B cell-specific gene expression program in HRS cells is disrupted by various molecular lesions. Furthermore, molecular and genomic defects of various signaling pathways could be identified in HRS cells, including the NF-kappaB, JAK/STAT and MAPK-AP-1 signaling pathways, which protect HRS cells from apoptotic cell death. Despite significant advances in the treatment of HL, the considerable long term toxicity of conventional therapies requires the development of new non-genotoxic therapeutic strategies. Therefore, it will be a central aim to develop new treatment strategies based on these insights into HL pathogenesis.

Modulation of regulatory T cells and myeloid-derived suppressor cells by sorafenib and sunitinib in renal cell carcinoma patients

e16002

Background: Induction of regulatory T (Treg) and myeloid-derived suppressor cells (MDSC) is a major mechanism for the escape of tumors from immunological control. Increased levels of Treg cells have been described in renal cell cancer (RCC) patients and seem to correlate with an adverse outcome. Furthermore, reduction of Treg has been reported for RCC patients under sunitinib therapy. The aim of our study was to analyse the influence of sorafenib and sunitinib on the frequency of Treg and MDSC in patients with metastatic RCC (mRCC). Methods: The number of T reg, MDSC and lymphocyte subpopulations was analysed by flowcytometry in peripheral blood (pb) of patients (n=19) with histologically confirmed mRCC under treatment with either sunitinib (50 mg/d, n=11) or sorafenib (800 mg/d, n=8). After informed consent blood samples were taken before and during the 1st, 2nd, and 3rd month of therapy. Flowcytometric analysis was performed using fluorochrome labeled antibodies against CD3, CD4, CD8, CD25, CD127, FOXp3, CD33, C14, CD11b and HLA-DR. Results: The baseline level of Treg did not differ from healthy controls. However, there was a significant increase of CD3+CD4+CD25+FOXp3+Treg (13,5% vs. 36,3% of gated cells, p= 0.02) and the ratio FOXp3+/FOXp3- CD3+CD4+ T cells (0,16% vs. 0,56% of gated cells, p= 0.02) in the group of sorafenib-treated patients compared to sunitinib-treated patients during the 1st month of therapy and thereafter. This effect was confirmed in an intragroup analysis. There was no influence of Sunitinib on the frequency of Treg. Analysis of CD33+/HLA-DR-/11b+ MDSC did not reveal any change under treatment with sorafenib or sunitinib. Conclusions: Sorafenib, but not sunitinib, leads to an early and sustained increase of Treg in pb of mRCC patients. A negative influence of sorafenib on primary immune responses has been described and has mainly been attributed to functional impairment of dendritic cells (DC). Whether altered DC function under sorafenib is responsible for the induction of Treg in RCC patients will have to be addressed in future studies. In immunoresponsive tumors such as RCC, immunological effects of kinase inhibitors are particularly relevant for the design of combination trials with immunotherapeutic agents.

No significant financial relationships to disclose.

Reactivation of hepatitis E infection in a patient with acute lymphoblastic leukaemia after allogeneic stem cell transplantation

Hepatitis E virus (HEV) is the major cause of several outbreaks of waterborne hepatitis in tropical and subtropical countries and of sporadic cases of viral hepatitis in endemic and industrialised countries. Generally, HEV causes an acute self-limiting hepatitis. The clinical course is characterised by transient viraemia and transaminasaemia followed by a full hepatic recovery. Recent studies describe prolonged and chronic HEV infections in some immunosuppressed patients after solid organ transplantation. Here, an indigenous acute limited hepatitis E in a patient with Philadelphia chromosome-positive acute lymphoblastic leukaemia prior to allogeneic stem cell transplantation is reported. Fourteen weeks after stem cell transplantation, reappearance of HEV viraemia was observed, with increasing viral load and modestly elevated serum transaminases. Sequence analysis of the viral RNAs revealed a reactivation of endogenous HEV genotype 3, indicating viral persistence after recovery from acute hepatitis E.

Allogeneic SCT in refractory or relapsed adult ALL is effective without prior reinduction chemotherapy

We present 60 patients with refractory (n=8) or relapsed (n=52) adult ALL who received allogeneic hematopoietic SCT (HSCT) with (n=41) or without (n=19) prior reinduction chemotherapy. In our center, omission of reinduction is recommended if a suitable donor is promptly available, tumor burden is moderate and disease features suggest a highly aggressive course. Overall survival (OS) of the whole cohort at 1, 2 and 5 years was 42, 33 and 28%, respectively. Leukemia-free survival at 1, 2 and 5 years was 37, 33 and 24%. Deaths were due to relapse (n=25), acute or chronic GVHD (n=7), infections (n=8) or toxicity (n=4). Interestingly, patients who did not receive reinduction before HSCT had better outcomes than patients who received reinduction with OS at 1, 2 and 5 years being 58 vs 34%, 47 vs 25% and 47 vs 18%, respectively (P=0.039). Importantly, even achievement of a second CR after reinduction was not associated with improved survival compared to patients directly proceeding to HSCT. We conclude that patients who undergo HSCT for refractory or relapsed ALL can achieve long-term survival. In selected patients, reinduction chemotherapy can be omitted if immediate HSCT is feasible.

Assessment of free light chains in the cerebrospinal fluid of patients with lymphomatous meningitis - a pilot study

BACKGROUND

Lymphomatous meningitis (LM) represents a severe complication of malignant lymphomas. While clinical suspicion is raised by symptoms ranging from mild disturbances of sensation to severe pain or impaired consciousness, the definite diagnosis of LM is often difficult to obtain. Since B-cell lymphomas are clonally restricted to express either kappa or lambda immunoglobulin light chain, we hypothesised that analysis of free light chain (FLC) ratios might facilitate the diagnosis of LM.

METHODS

Kappa and lambda FLC were measured using a novel nephelometric assay in cerebrospinal fluid (CSF) and serum from 17 patients. 5/17 suffered from LM as demonstrated by cytology, immunocytology, and/or imaging procedures.

RESULTS

Measurement of FLC concentrations in CSF was achieved for all 17 patients. FLC levels in CSF were lower than serum FLC levels in samples for the same patient obtained at the same time (p < 0.01). CSF and serum FLC concentrations correlated weakly in all patients irrespective of LM status. Significantly more patients with cytopathologically and immunohistochemically proven LM displayed abnormal kappa/lambda FLC ratios in CSF compared to individuals with no LM (p < 0.01).

CONCLUSION

This is the first report demonstrating that a significant proportion of LM patients display an abnormal kappa/lambda FLC ratio in the CSF.

In vivo splenic CD11c cells downregulate CD4 T-cell response thereby decreasing systemic immunity to gene-modified tumour cell vaccine

One of the factors influencing the efficacy of tumour cell vaccines is the site of immunization. We have shown previously that gene-modified vaccines delivered directly inside the spleen induced antigen cross-presentation by splenic antigen-presenting cells (not B cells). Here, we examined the interaction between splenic CD11c(+) cells and antigen-specific CD4(+) T cells. We used tumour cells expressing ovalbumin (OVA), a situation where CD4(+) T-cell help is required for the generation of a cytotoxic T lymphocyte response. Using in vivo bioluminescence imaging of luciferase-expressing EL4-OVA cells, we could demonstrate that tumour cells were located exclusively inside the spleen following intrasplenic injection. We showed that after intrasplenic immunization with T/SA-OVA cells, splenic class I(+) class II(+) CD11c(+) cells engulfed and presented in vivo the OVA class I-restricted peptide SIINFEKL. However, in vivo previously adoptively transferred 5,6-carboxy-succinimidyl-fluorescein-ester-labelled transgenic CD4(+)KJI-26(+) cells specific for the class II OVA(323-339) peptide underwent abortive proliferation in the spleen. These CD4(+)KJI-26(+) cells were only transiently activated and produced IL-10 and IL-4 and not IFN-gamma. It appears that splenic CD11c(+) cells can downregulate splenic specific CD4(+) T-cell response thereby leading to a decrease in antitumour systemic immunity.

HLA-A0201-positive, IL-7/B7.1-cotransfected allogeneic tumor cells as a vaccine in metastatic renal cell cancer—A clinical phase-I trial

3072

Background: Tumor vaccination remains a promising experimental approach in RCC. HLA-A0201-restricted T cell immunity against RCC is well established. RCC26 is an allogeneic HLA-A0201+ human RCC cell line, a T cell clone specifically recognising RCC26 and other RCC in the context of HLA-A0201 has previously been generated, the TCR of this T cell clone was characterised. Furthermore, IL-7/B7.1 cotransfected tumor cells are a potent vaccine in animal models. Methods: RCC26 was transfected with pKEx-IL-7-IR-B7 coding for human IL-7 and B7.1 (CD80). 10 HLA-A0201+ patients with metastatic RCC and disease progression under cytokine therapy were included. 10 vaccinations with 2.5–40x106 gene-modified irradiated tumor cells which had been produced under GMP conditions were performed s.c. over 22 weeks. Primary endpoints of the study were feasibility, safety and immunological response, secondary endpoint was clinical response. The protocol was approved by the ethics committee, all patients gave informed consent. Results: Gene-modified RCC26 cells produced IL-7 (3.4 ng/106 cells/24h), more than 90% of the cells were CD80+. Vaccination was feasible and safe with no severe toxicity. Local DTH-reactions were observed in 4 patients. Skin biopsies of the vaccination site showed lymphocytic infiltrates dominated by CD4+T cells. In 8 patients vaccination induced HLA- and /or antinuclear antibodies without clinical signs of autoimmunity. Analysis of the T cell response against RCC-associated antigens is under way. No partial or complete responses could be documented. However, 50% of the patients had stable disease with the longest TTP being 69 weeks. Mean TTP in our cohort was 25 weeks (range 4 to 69 weeks). Conclusion: Our results show that vaccination with an allogeneic gene-modified tumor cell line is feasible and safe. Stable disease lasting up to 69 weeks in a substantial proportion of patients suggests immunological activity of the vaccine. Vaccination of patients with a low tumor burden is a promising strategy for the future, i.e. after surgery or treatment with novel multi-kinase inhibitors.

No significant financial relationships to disclose.

A randomized second line trial in patients with gemcitabine refractory advanced pancreatic cancer - CONKO 003

4517

Objective: For nearly ten years gemcitabine (G) was standard first line therapy for patients (pts) with advanced pancreatic cancer (APC). There is no consensus about second line therapy after disease progression while receiving G, but 5-FU-based regimens are considered. Results about randomized second line studies in APC are very rare. Our phase II study (ASCO 2002) showed activity of the OFF (oxaliplatin/folinic Acid (FA)/5-fluorouracil (FU) [24h] ) regimen in 23 pts. To examine the impact and the side effects of oxaliplatin we initiated a multicenter phase III study to compare OFF and FF in pts with G refractory APC. Methods: Pts with CT/ MRT confirmed failure with G in first line therapy, Karnofsky Performance Status (KPS) >60%, controlled pain, adequate hematological, renal and liver functions were eligible. Pts were stratified according to duration of first line therapy, KPS and tumor stage. We randomized pts to outpatient treatment with FF (FU 2g/m2 (24h)/ FA 200 mg/m2 (30min) on d1, d8, d15 and d22) or OFF (FF+Oxaliplatin 85mg/m2, d8, d22). In both arms the next cycle started on day 43. Pts were followed with regular staging every 3 months or at any signs of disease progression. Results: Until now we randomized 161 of 165 (planned) pts between 02/2004 and 01/2007. So we expect to present first results (side effects, progression free survival, overall survival) at the meeting.

No significant financial relationships to disclose.

CCL19 (ELC) as an adjuvant for DNA vaccination: induction of a TH1-type T-cell response and enhancement of antitumor immunity

Coexpression of tumor antigens together with immunomodulatory molecules is a strategy in DNA vaccination aiming at an amplification of the antitumor immune response. Epstein-Barr virus-induced-molecule-1-ligand-chemokine (ELC/CCL19) is a CC chemokine that binds to the chemokine receptor CCR7. CCR7 is expressed on mature dendritic cells (DC) and distinct T- and B-cell subpopulations. CCL19 (ELC) is mainly expressed in secondary lymphoid organs and plays a central role in regulating the encounters between DC and T cells. We asked whether CCL19 is able to augment immunogenicity of a DNA vaccine in a C57BL/6 mouse model with syngeneic MCA205 (beta-gal) tumor cells. Mice were vaccinated twice intramuscularly on days 1 and 15 and tumor challenge was performed subcutaneously on day 25. Coadministration of plasmid DNA (pDNA) (beta-gal) plus pDNA (CCL19) was compared with pDNA (beta-gal), pDNA (CCL19), mock vector and phosphate-buffered saline (PBS) alone. Coexpression of CCL19 resulted in enhancement of a Th1-polarized immune response with substantial improvement of the protective effect of the DNA vaccine. Immunohistochemical staining revealed an increased CD8+ T-cell infiltration in the tumor tissue of mice that had been immunized with pDNA (beta-gal) plus pDNA (CCL19). We conclude that CCL19 is an attractive adjuvant for DNA vaccination able to augment antitumor immunity and that this effect is partially caused by enhanced CD8+ T-cell recruitment.

Initial chemotherapy with mitoxantrone, chlorambucil, prednisone impairs the collection of stem cells in patients with indolent lymphomas—results of a randomized comparison by the German Low-Grade Lymphoma Study Group

Myeloablative radio-chemotherapy with subsequent autologous stem cell transplantation (ASCT) significantly prolongs progression free and probably overall survival in follicular lymphoma (FL) in first remission. The current trial explored prospectively the rate of successful stem cell mobilization in patients with advanced stage FL after initial therapy with either Mitoxantrone, Chlorambucil, Prednisone (MCP) or Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (CHOP) as part of a prospective randomized comparison of both regimens. ASCT patients received Dexa-BEAM (Dexamethasone, BCNU, Melphalan, Etoposide, Cytarabine) for mobilization of stem cells. Stem cells were collected and a minimum of 2x2.0x106/kg bw CD34+ was required for ASCT. Of 79 evaluable patients, 58 (73%) had follicular lymphoma, 13 (16%) mantle cell lymphoma and 8 (10%) lymphoplasmacytic lymphoma. In the 45 patients assigned to CHOP, stem cell collection was successful in 42 cases (93%, 95% CI 82% to 99%). This high mobilization rate after CHOP could be confirmed in 61 subsequent patients (87%). In contrast, after MCP therapy stem cell collection was successful in only 15 of 34 patients (44%, 95% CI 27% to 62%; P=0.0003). In conclusion, initial therapy with MCP significantly impairs the ability to collect stem cells and should be avoided for first line therapy of younger patients potentially qualifying for high dose consolidation and ASCT in first remission.

Bak functionally complements for loss of Bax during p14ARF-induced mitochondrial apoptosis in human cancer cells

In contrast to the initial notion that the biological activity of p14(ARF) strictly depends on a functional mdm-2/p53 signaling axis, we recently demonstrated that p14(ARF) mediates apoptosis in a p53/Bax-independent manner. Here, we show that p14(ARF) induces breakdown of the mitochondrial membrane potential and cytochrome c release before triggering caspase-9- and caspase-3/7-like activities in p53/Bax-deficient DU145 prostate cancer cells expressing wild-type Bak. Re-expression of Bax in these cells failed to further enhance p14(ARF)-induced apoptosis, suggesting that p14(ARF)-induced apoptosis primarily depends on Bak but not Bax in these cells. To further define the role of Bak and Bax in p14(ARF)-induced mitochondrial apoptosis, we employed short interference RNA for the knockdown of bak in isogeneic, p53 wild-type HCT116 colon cancer cells either proficient or deficient for Bax. There, combined loss of Bax and Bak attenuated p14(ARF)-induced apoptosis whereas single loss of Bax or Bak was only marginally effective, as in the case of DU145. Notably, HCT116 cells deficient for Bax and Bak failed to release cytochrome c and showed attenuated activation of caspase-9 (LEHDase) and caspase-3/caspase-7 (DEVDase) upon p14(ARF) expression. These data indicate that p14(ARF) triggers apoptosis via a Bax/Bak-dependent pathway in p53-proficient HCT116, whereas Bax is dispensable in p53-deficient DU145 cells. Nevertheless, a substantial proportion of p14(ARF)-induced cell death proceeds in a Bax/Bak-independent manner. This is also the case for inhibition of clonogenic growth that occurs, at least in part, through an entirely Bax/Bak-independent mechanism.

Capecitabine and docetaxel for advanced gastric cancer

4068

Background: Docetaxel is increasingly integrated into chemotherapy combination regimens against gastric cancer. Docetaxel and 5-FU were compared to ECF and appeared to be very active and well tolerated (Thuss-Patience et. al. JCO 2005). In the current study the dual combination capecitabine and docetaxel (CapDoc) is evaluated to develop a convenient out-patient regimen with minimal toxicity. Methods: Prospective multicenter phase II trial. Eligibility: Metastatic or locally advanced gastro-esophageal junction or gastric adenocarcinoma, ECOG PS 0–2, no prior palliative chemotherapy. Chemotherapy: Docetaxel 75 mg/m2 d1, capecitabine 2000 mg/m2 d1–14, q3w. For part I of the study (presented here) accrual is completed (40 pts). In part II we reduced the starting dose of docetaxel to 60 mg/m2 and capecitabine to 1600 mg/m2 to further improve tolerability (accrual ongoing, 8 pts included so far, presented at meeting). Results: 40 pts are included in this trial (part I). Age: 32–79 years (median 61), M/F 29/11, ECOG PS 0: 7 pts, 1: 27 pts, 2: 6 pts. Number of organs involved by metastases: 1: 9 pts, 2: 11 pts, 3: 16 pts, more than 3: 4 pts. Measurable disease (RECIST): 40 pts. 233 cycles of chemotherapy are administered so far. Toxicity: 40 pts are evaluable for toxicity (worst grade per patient; % of pts): Grade 1/2/3/4: Nausea: 53/10/3/- %, vomiting: 18/13/-/3 %, diarrhea: 23/20/13/- %, asthenia: 38/40/10/- %, stomatitis: 23/15/10/- %, alopecia: 25/53/-/- %, fever not neutropenic: 10/20/3/- %, neutropenic fever: -/-/10/3 %, nail changes: 33/28/-/- %, paresthesia: 18/18/5/- %, dizziness: 15/8/5/- %, hand-foot-syndrome: 25/18/18/- %, leuko-neutropenia: 8/13/25/28 %, thrombocytopenia: 18/-/-/- %, anemia: 40/15/5/- %, fluid retention: 13/5/-/-, pulmonary embolism or thrombosis: 3/5/3/5. Dose adjustments of docetaxel had to be made in 45% and of capecitabine in 55% of pts. Response: 26 of 37 pts with tumor related symptoms showed a subjective improvement of symptoms (70.3%). 38 pts are evaluable for objective response: CR 1 pt (2.6%), PR 20 pts (52.6%), NC 14 pts (36.8%), PD 3 pts (7.9%), (objective response rate: 55.3%). Median time to tumor progression 5.5 months, median survival 9.5 months. Conclusion: These data suggest that CapDoc is a well tolerated convenient out-patient combination with very promising efficacy.

[Table: see text]

CONKO-101: Results of a multicenter phase II study of an outpatient regimen consisting out of gemcitabine, 5-FU (24h CI), folinic acid and cisplatin for patients with inoperable esophageal cancer

4066

Background: Standard therapy for inoperable esophageal cancer is a combination of cisplatin and 5-FU combined with radiation for locally advanced stages. As gemcitabine shows synergy with cisplatin and 5-FU, we evaluated the combination of cisplatin 30 mg/m2 (90 min), Gemcitabine 1000 mg/m2 (30 min), FS 200 mg/m2 (30 min) and 5-FU 750 mg/m2 24h CI) d1,8 q d22 for patients with inoperable esophageal cancer. For locally advanced stages, patients received sequential radiochemotherapy with 5-FU CI. Methods: 89 (75 m/14 w) pts. were included into this multicentrical phase 2 study. 58 had SCC, 30 AC, 1 pt. had undifferentiated carcinoma. Median age was 61 (22–86), Median KI 90 (60–100). 2 pts. had stage IIa, 4 stage IIb, 30 stage III, 16 stage IVa and 37 stage IVb. Results: 71 pts. are so far evaluable for response and 84 for toxicity. 2 pts. (2.8%) had CR (1 pathologically confirmed), 27 pts. had PR (38.1%), 33 pts. had SD (46.5%) and 9 pts. had PD (12.6%) as best response. MS was 10.7 months (13.1 for stage II/III and 9.1 for stage IV). Median TTP was 6 months, and PFS was 6 months. Observed toxicity was low and predominantly hematologic with Leukopenia Grade III/IV in 10% of cycles, Hb Grade III/IV in 5.3% of cycles and Thrombopenia Grade III/IV in 2.4% of cycles. Conclusion: This regimen is well tolerable and can easily be applied on an outpatient base. The remission rates and survival data are within the range previously reported in other phase II studies.

No significant financial relationships to disclose.

A prospective, randomized trial of simultaneous pancreatic cancer treatment with enoxaparin and chemotherapy (PROSPECT - CONKO 004)

4110

Background: Approximately 20% of patients (pts) diagnosed with pancreatic adenocarcinoma (PA) develop venous thromboembolism, which may contribute to the dismal prognosis of PA. A small phase II trial suggested an improved survival by the addition of low molecular weight heparin (LMWH) to chemotherapy (Icli et al., ASCO 2003). We conducted a small pilot study which indicated that the addition of enoxaparin to chemotherapy GFFC chemotherapy (see below) is safe and feasible in pts with advanced PA. Furthermore, results of several phase III studies suggest that pts in good performance status may benefit from more intensive chemotherapy regimen (Riess et al; Heinemann et al; ASCO 2005). Based on these considerations we started the multicenter phase III study CONKO 004. Methods: 540 patients are to be recruited into this study. Primary stratification takes place according to Karnowsky performance status and kidney function. Patients with KPS > 80% and normal kidney function receive GFFC ± LMWH (gemcitabine 1 g/m2 (30 min), cisplatin 30 mg/m2 (90 min), 5-fluorouracil 750 mg/m2 (24 h), folinic acid 200 mg/m2 (30 min), d1, 8; q3w ± Enoxaparin 1mg/kg daily s.c.). Pts with KPS < 80 % and increased creatinin plasma levels (>1.3 mg/dl) receive the current standard therapy (gemcitabine 1 g/m2 (30 min), d1, 8, 15; q4w) ± LMWM ± Enoxaparin 1mg/kg daily s.c. After 12 weeks of initial chemotherapy all patients who have not progressed received the standard therapy (gemcitabine 1 g/m2 (30 min), d1, 8, 15; q4w) ± Enoxaparin 40mg daily s.c. Results: From April 2004 to Dezember 2005 140 pts have been recruited in this study. Until now no unexpected serious adverse events concerning severe bleedings were observed in the enoxaparin treatment group. No heparin induced thrombocytopenia (HIT II) was documented. The first interim analysis per protocol is planned after 12 pts. with deep vein thrombosis or thromboembolic events. This interim analysis is expected to be completed in May 2006. Conclusions: Our observations indicate that the addition of enoxaparin—given the dosage mentioned above—to GEM/GFFC is safe, does not change toxicity and maintains activity of chemotherapy in pts with advanced PA. This study is open to recruitment.

No significant financial relationships to disclose.