ALBERT

Description: Abstract 1804 Introduction: Advanced stage follicular lymphoma (FL) cannot be cured by current conventional therapies. Treatment with idiotype cancer vaccines has thus far been disappointing, and is expensive and labor intensive. Hence, simpler principles for vaccinations that do not require production of patient-specific tumor antigens are warranted. We designed a novel strategy involving intratumoral injections of low-dose anti-CD20 antibody (Rituximab) and autologous dendritic cells (DC) in irradiated lymph nodes. The aim was to facilitate antigen up-take and presentation by DCs to T cells to achieve systemic anti-tumor responses in patients with FL. Method: Ten untreated patients with stage III/IV follicular lymphoma not in need of conventional therapy underwent standard work-up, including CT-scans, FDG PET/CT and bone marrow samples. Single tumor cells were frozen for later immunoassays. Apheresis was performed for isolation of monocytes subsequently cultured with IL-4 and GM-CSF for 5 days to generate immature dendritic cells (DC). The first 6 patients received a single 8 Gy dose of radiotherapy against an enlarged node on day 1, followed by intratumoral injections of DCs (1 × 108) and GM-CSF (50 μg) on days 3 and 4. The treatment was repeated against a different enlarged node after 6 weeks. Thereafter, the protocol was changed, and patients received intratumoral injections of a small dose of rituximab (5 mg) on days 1 and 3 in order to enhance ADCC, radiotherapy (8 Gy) on day 2 and intratumoral injections of DCs and GM-CSF sc on days 4 and 5. This therapy was then repeated after 2 and 4 weeks, targeting other lymph nodes. Follow-up included repeated PET/CT-scans, bone marrow sampling and preparation of peripheral blood mononuclear cells (PBMC) for later immune studies. Tumor-specific helper and cytotoxic T cell responses were monitored by flow cytometry after a 5-day co-culture of single tumor cells with autologous PBMC sampled before, and 2 and 4 months after, treatment. Proliferation was studied by incorporation of CFSE, whereas degranulation (CD107a/b) and interferon gamma release was measured following re-stimulation with tumor cells for 5h. Result: Ten patients with FL of a total of 20 planned for this study were treated so far. No adverse events were observed. Among the first 6 patients treated by the original strategy, two showed a systemic metabolic response by PET/CT and one of these had a good response by regular CT not qualifying for PR. The protocol was then modified as described above. The first patient treated by the new strategy that included intratumoral rituximab, had a systemic metabolic response by PET/CT after 2 and 4 months and was PET negative with a normal CT by 8 months (Figure 1). Another patient showed a systemic PET response at 2 and 4 months. Analysis of T cell responses against autologous tumor cells has been initiated and we have so far demonstrated a vigorous CD8 dominated T cell response, as assayed by proliferation, degranulation and cytokine production, in the patient who achieved a negative PET-scan at 8 months (Figure 2). In parallel with the metabolic response, the immune response became stronger during follow-up after treatment. One patient without clinical response was also analysed, and no immune response was demonstrated. Further analysis of immune responses in the other patients is on-going. Conclusion: The present strategy is a novel principle to generate T cell responses and clinical anti-tumor responses detected by PET/CT in FL. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 747 The outcome of mantle cell lympoma (MCL) has improved in recent years. The Nordic Lymphoma Group has since 1996 completed three consecutive phase II trials for front-line treatment of MCL patients 〈 66 years of age. The first trial (MCL1) showed that quality of response prior to transplant was the most important factor for outcome. Hence, in the second trial (MCL2) induction therapy was intensified by adding cycles of high-dose Ara-C and rituximab to the regimen. Despite significant improvement in overall and progression-free survival, patients who did not achieve CR pretransplant had a shorter time to progression. Therefore, the main objective of the MCL3 study was to improve the time to progression in patients who achieved only CRu or PR pretransplant by adding Zevalin to the high-dose regimen as a late intensification. Results of the – otherwise largely identical - MCL2 trial serve as the historic control. Methods: Newly diagnosed stage II-IV MCL patients 〈 66 years received induction immunochemotherapy with alternating cycles of R- (rituximab) maxi-CHOP and R-Ara-C to a total of 6 cycles. Evaluation of pretransplant response with CT scans and bone marrow was performed after 5 cycles. PET/CT pretransplant was recommended, but would not influence treatment. Responding patients by NCI criteria underwent in-vivo purged stem cell harvest after the 6th cycle (Ara-C + 2 doses of rituximab). Patients in CRu or PR received a standard dose Zevalin (0.4 mCi/kg) one week prior to high-dose therapy with BEAM or BEAC while CR patients received the high-dose chemotherapy without Zevalin. Follow-up included CT-scans, bone marrow and blood sampling for at least 5 years, including PCR for minimal residual disease or molecular relapse. Patients in solely molecular relapse received preemptive therapy with 4 weekly doses of rituximab, as in the MCL2 study. Results: 161 consecutive patients were included from 2005–2009, with characteristics similar to that of the MCL2 trial with a median age of 57 years (28–65), a male predominance and the majority in stage IV with bone marrow involvement. Only 12 out of 161 patients (7 %) did not receive a transplant, 6 due to stem cell harvest failure, 2 due to toxicity and 4 due to no response to induction treatment. Before transplant 50% were in CR, 17% in CRu, and 30% in PR. Only four out of 161 patients (2 %) did not respond to induction treatment. After a median follow-up of 3.2 years the projected 5-year overall and event free survival, and time to progression were 71, 55 and 65% respectively and the MCL2 and MCL3 curves were superimposable. Of the 69 candidates to Zevalin in CRu/PR according to protocol, 65 (94%) actually received this treatment. There was no significant difference in time to progression for patients in CRu and PR pretransplant between MCL2 and MCL3, indicating no effect of late intensification with Zevalin in MCL3 in this patient group. Interestingly, a positive pretransplant PET scan proved to be a strong negative predictor for outcome. Lack of benefit from addition of Zevalin to the high-dose regimen was shown for both PET-positive and PET-negative patients. In a multivariate analysis of the impact of clinical response, PET positivity and zevalin treatment, only PET positivity pretransplant had independent significance (p=0.0003 HR=3.412 (95% confidence limits 1.744 – 6.673). The treatment-related mortality was 3 %. Side-effects were similar to that previously reported for MCL2, and we did not find that Zevalin added any toxicity. Of the 3 patients who developed secondary MDS/AML posttransplant, two had received Zevalin and one had not. Conclusion: The MCL3 data confirm the good results and tolerability of the Nordic regimen. However, the late intensification with Zevalin, albeit non-toxic, did not prolong the time to progression for patients in only CRu or PR pretransplant. A positive PET prior to transplant was shown to be a strong negative predictor for outcome. The concept of late intensification may be too late in poor responders. In consequence, up-front intensification with increasing use of high-dose AraC for MIPI high-risk patients is used in the subsequent, now ongoing Nordic-British MCL5 study. Disclosures: Arne: Bayer Schering Pharma: Research Funding. Geisler:Roche, Schering: Consultancy, Research Funding.

Description: Key PointsZ-BEAM/C did not improve outcome for patients in only PR or CRu before transplant. Positive PET before transplant and MRD after transplant predicted inferior PFS and OS.

Description: Abstract 932 The Nordic Lymphoma Group has since 1996 conducted three consecutive phase II trials for front-line treatment of MCL patients ≤ 65 years of age. The first protocol (MCL1) 1996-2000 introduced high-dose chemotherapy with autologous stem cell support (unpurged or ex vivo purged) as consolidation after 4 cycles of intensified CHOP (maxi-CHOP). The results were disappointing, as the majority of patients relapsed. 1 Being in CR pre-transplant was the most important factor for outcome. Hence, in the second trial (MCL2) 2000-2006 induction therapy was intensified by adding high-dose Ara-C and rituximab to the regimen. Compared to MCL1 this led to significant improvement of event-free and overall survival, and the rate of PCR negative stem cell grafts and bone marrow samples.2 Again, responders in less than CR pre-transplant had a significantly poorer outcome. We therefore made a further intensification for the MCL3 study (2006-2009) by adding 90Y-Ibritumomab tiuxetan (Zevalin®) to the high-dose BEAC/BEAM to responders not in CR. Methods: As in the MCL1 and 2 studies newly diagnosed stage II-IV MCL patients ≤ 65 years were included. Induction treatment was identical to that of the MCL2 study with alternating cycles of maxi-CHOP-rituximab (3 cycles) and Ara-C-rituximab (3 cycles). Response evaluation was done after cycle 5. PET/CT was recommended, but could not influence the response evaluation, which was done according to the International Workshop criteria. Responders underwent in vivo purged harvest of stem cells after cycle 6 (Ara-C + 2 doses of rituximab). Patients in CRu or PR received a standard dose 90Y-Ibritumomab tiuxetan (0.4 mCi/kg) one week prior to the BEAM/BEAC, CR patients received BEAM/BEAC alone. Patients are followed by CT-scans, bone marrow and blood samples, including PCR for minimal residual disease or molecular relapse. For molecular relapse preemptive treatment with 4 standard doses of rituximab, as in the MCL2 study3, is given. Results: The planned accrual of 160 patients was reached in June 2009. The patient characteristics are similar to those of the MCL2 trial with a median age of 57 years (28-65), the majority male (80%) and in stage IV (89%) with bone marrow involvement (74%). The response rates pre-transplant so far compare favorably with data from MCL2 with 50% in CR, 18% in CRu, and 28% in PR. Only 4 out of 128 evaluable patients did not respond (3%) and there was one case (1%) of treatment-related mortality during induction therapy. While it is still too early to assess the impact of the 90Y-Ibritumomab tiuxetan on the progression-free survival, the side effects were similar to those of the MCL2 study including a treatment related mortality of 4%. Fifty-five patients in CRu or PR have so far been treated with 90Y-Ibritumomab tiuxetan, with no indication of any added toxicity. Only 12 out of 133 patients (10%) have not undergone transplant, 5 due to stem cell harvest failure, 3 due to toxicity and 4 due to non response to induction treatment. PET-scan prior to transplant was positive in 2% of CR patients, 20% of CRu patients and 54% of PR patients. Patients with a positive PET-scan pre-transplant had a 36% chance of achieving a molecular remission post-transplant, compared to 92% of cases with a negative PET-scan (p

Description: Key Points Local immunotherapy induced systemic responses in patients with disseminated FL. Clinical responses correlated with systemic antitumor T-cell immunity.