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TPS7132 Background: The poor prognosis and lack of effective treatment options for patients with r/r CLL highlight the need for novel therapies in this setting. CD19 is a promising anticancer target because it is broadly expressed on normal and malignant B cells through several stages of maturation but absent on pluripotent stem cells. CART-19 (CTL019) therapy involves adoptive transfer of autologous T cells genetically modified via lentiviral transduction to express chimeric antigen receptors (CAR) designed to target CD19+ cells. CART-19 cells express a CD19 antigen recognition domain combined with intracellular signaling domains, CD137 (4-1BB) and CD3-zeta, which mediate cytolytic T-cell activity. In patients with r/r CLL, CART-19 therapy showed potent antileukemic activity with long-term persistence of transduced cells at doses from 1.4 × 107 to 1.1 × 109 CART-19 cells. As of August 2012, 3 of 8 evaluable CLL patients achieved CR (two > 24 months and one > 5 months) and remain in CR with detectable CART-19 cells. Two patients had PR lasting 3 and 5 months, and 3 patients did not respond (Porter et al. NEJM. 2011; Kalos et al. Sci Transl Med. 2011; Porter et al. ASH 2012). Here, we describe a study to determine the optimal dose of CART-19 cells (NCT01747486). Methods: Adults with relapsed or persistent CLL or SLL after ≥ 2 previous therapies will undergo leukapheresis to obtain T cells, which will be stimulated, expanded, and lentivirus transduced ex vivo to express the CD19/4-1BB/CD3-zeta CAR. Patients will undergo lymphodepletion chemotherapy prior to infusion of CART-19 cells. In stage I of the II-stage trial, 30 patients will be randomized 1:1 and receive either 1-5 × 108 or 1-5 × 107 CART-19 T cells. The optimal dose in stage I will be selected based on clinical responses, feasibility, and tolerability. In stage II, 8 additional patients will be enrolled into the selected dose cohort. Study objectives are to determine the efficacy (CR rate within 3 months) and safety (CTCAE v 4.0) of each dose, in vivo CART-19 expansion, and manufacturing feasibility. Three patients have been enrolled as of January 2013. Clinical trial information: NCT01747486.

Abstract 2604 We previously reported on CART19 cells expressing a chimeric antigen receptor (CAR) with intracellular activation and costimulatory domains. Infusion of these cells results in 100 to 100,000× in vivo proliferation, tumor lysis syndrome followed by durable antitumor activity, and prolonged persistence in pts with B cell tumors. Here we report that in vivo proliferation of CART19 cells and potent anti-tumor activity is associated with CRS, leading to hemophagocytic lymphohistiocytosis (HLH), also termed MAS. We propose that MAS/HLH is a unique biomarker that is associated with and may be required for potent anti-tumor activity. Autologous T cells were lentivirally transduced with a CAR composed of anti-CD19 scFv/4-1BB/CD3-zeta, activated/expanded ex-vivo with anti-CD3/anti-CD28 beads, and then infused into ALL or CLL pts with persistent disease after 2–8 prior treatments. CART19 anti ALL activity was also modeled in a xenograft mouse model with high level of human ALL/human T cell engraftment and simultaneous detection of CAR T cells and ALL using 2-color bioluminescent imaging. We describe updated results of 10 pts who received CART19 cells elsewhere at ASH (Porter, et al), including 9 pts with CLL and 1 pediatric pt with relapsed refractory ALL. 6/9 evaluable pts had a CR or PR, including 4 sustained CRs. While there was no acute infusional toxicity, all responding pts also developed CRS. All had high fevers, as well as grade 3 or 4 hypotension/hypoxia. CRS preceded peak blood expression of CART19 cells, and then increased in intensity until the CART19 cell peak (D10–31 after infusion). The ALL pt experienced the most significant toxicity, with grade 4 hypotension and respiratory failure. Steroid therapy on D6 resulted in no improvement. On D9, noting high levels of TNFa and IL-6 (peak increases above baseline: IFNg at 6040x; IL-6 at 988x; IL-2R at 56x, IL-2 at 163× and TNFa at 17x), we administered TNFa and IL-6 antagonists entanercept and toc. This resulted in resolution of fever and hypotension within 12hr and a rapid wean from ventilator support to room air. These interventions had no apparent impact on CART19 cell expansion or efficacy: peak of CAR T cells (2539 CAR+ cells/uL; 77% of CD3 cells by flow) occurred on D11, and D23 bone marrow showed CR with negative MRD, compared to her initial on-study marrow which showed 65% blasts. Although she had no history of CNS ALL, spinal fluid showed detectable CART19 cells (21 lymphs/mcL; 78% CAR+). At 4mo post infusion, this pt remains in CR, with 17 CART19 cells/uL in the blood and 31% CAR+ CD3 cells in the marrow. Clinical assessment of subsequent responding patients shows all had evidence of MAS/HLH including dramatic elevations of ferritin and histologic evidence of HLH. Peak ferritin levels range from 44,000 to 605,000, preceding and continuing with peak T cell proliferation. Other consistent findings include rapid onset hepatosplenomegaly unrelated to disease and moderate DIC. Subsequently, 3 CLL patients have also been treated with toc, also with prompt and striking resolution of high fevers, hypotension and hypoxia. 1 received toc on D10 and achieved a CR accompanied by CART19 expansion. 1 had rapid resolution of CRS following toc administration on day 9 and follow up for response is too short. A 3rd CLL pt received toc on D3 for early fevers and had no CART-19 proliferation and no response. To model the timing of cytokine blockade, xenografts using bioluminescent primary pediatric ALL were established and then treated with extra cells from the clinical manufacture. The CART19 cells proliferated and resulted in prolonged survival. Cytokine blockade prior to T cell infusion with toc and/or etanercept abrogated disease control with less in vivo proliferation of infused CART19 cells, confirming the result seen in the one pt given early toc (D3). The optimal time and threshold to trigger cytokine blockade is currently being tested in these models. CART19 T cells can produce massive in-vivo expansion, long-term persistence, and anti-tumor efficacy, but can also induce significant CRS with features suggestive of MAS/HLH that responds rapidly to cytokine blockade. Given prior to initiation of significant CART19 proliferation, blockade of TNFa and/or IL-6 may interfere with proliferation and effector function, but if given at a point where cell proliferation is underway, toc may ameliorate the symptoms that we have observed correlate with robust clinical responses. Disclosures: Off Label Use: tocilizumab for cell therapy toxicity. Levine:University of Pennsylvania: financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight Patents & Royalties; TxCell: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kalos:University of Pennsylvania: Patents & Royalties. June:Novartis: Research Funding, institution owned patents have been licensed by Novartis, institution owned patents have been licensed by Novartis Patents & Royalties.

Abstract 352 Background: Autologous stem cell transplantation (ASCT) for MM leads to complete responses in ∼20–40% of patients but rare cures. Patients with rapid recovery of T cells post ASCT may have improved outcomes suggesting possible immune mediated tumor control. We have shown that adoptive T-cell transfers after ASCT for MM using vaccine-primed and ex-vivo costimulated autologous T-cells in combination with pre- and post-transplant immunizations using a tumor antigen vaccine (+ GM-CSF and montanide) led to vaccine-directed T-cell responses in about 1/3 of patients and enhanced recovery of polyclonal T and B cell counts and function. We hypothesized that addition of Poly-ICLC (Hiltonol®) – a TLR-3 agonistic vaccine adjuvant could increase tumor antigen vaccine responses through better priming and boosting. Methods: We report interim results of a Phase II clinical trial (NCT01245673) evaluating safety and activity of autologous T cells primed in-vivo with a MAGE-A3 multipeptide vaccine (Orphan Drug Designation: GL-0817) mixed with GM-CSF and Poly-ICLC (Hiltonol®) +/− montanide. Inclusion criteria included measurable disease or high-risk cytogenetics. MAGE-A3 is expressed in ∼50% MM cases and more frequently in relapsed/extramedullary/proliferative disease. The MAGE-A3 vaccine has 2 HLA-A2-restricted class I peptides and 1 promiscuous class II peptide linked to an HIV-1-TAT membrane translocation sequence (Trojan peptide) to enhance peptide presentation. Vaccine-primed T cells were collected by leukapheresis, costimulated and expanded ex-vivo using anti-CD3/anti-CD28 mAb conjugated beads. T-cells were infused at day +2 after ASCT followed by booster immunizations at days 14, 42, 90, 120 and 150 post-transplant. Lenalidomide maintenance was started at day +100. Patients were evaluated for MM responses in accordance with IMWG criteria at days 60, 100, 180 post-transplant and Q3 months thereafter. T-cell and B-cell responses to the vaccine were evaluated by IFN-g or IL-2 cytokine production (all patients), dextramer binding to CD8 cells (HLA-A2 positive patients) and ELISA antibody assays at days 14, 60, 100 and 180 post-transplant. Results: 25 patients were transplanted on study. At a median followup of 6 months (range 2–18 months), 24 patients are surviving while 1 patient relapsed at about day +60 and died. Four additional patients have relapsed at 7,9,18 and 18 months post-transplant, yielding a 1-year Kaplan-Meier EFS of 77%. Of the 16 patients evaluable for response at day 100, 7/16 (44%) had CR/nCR using the study enrollment (post-induction) myeloma markers as a baseline while at day 180, 7/13 (53%) had CR/nCR. T-cell infusions were well-tolerated with no probable/definite grade 3 or higher toxicities. Vaccinations were associated with > 50 mm injection site reactions (redness, induration or both) after 1 or more immunizations in the majority of patients. Two patients developed large and prolonged inflammatory reactions which evolved into sterile abscesses. These resolved over 2–3 months with conservative management but as a result montanide was eliminated from the vaccine formulation for patients 11–25. Thereafter vaccine reactogenicity was decreased with no additional sterile abscesses. Of 16 patients tested for immune responses to date, 2 patients were unevaluable due to poor sample viability. Dextramer staining demonstrated MAGE-A3-specific CD8 T-cells in 4/4 (100%) of evaluable HLA-A2+ patients. Cytokine production in response to MAGE-A3 stimulation was seen in 11/14 (79%) patients; responses usually peaked at day 100 or day 180. Robust MAGE-A3 antibody responses were detected in 7/9 patients who received montanide in the vaccine formulation but in 0/7 patients who did not. Conclusions: Combination immunotherapy using a MAGE-A3 multipeptide tumor antigen vaccine plus vaccine-primed and costimulated autologous T-cells after ASCT for MM is well-tolerated and associated with encouraging early clinical responses. The addition of Poly-ICLC (Hiltonol®) to the vaccine formulation was associated with a high frequency of post-ASCT T-cell functional responses. The combination of Poly-ICLC +GM-CSF + Montanide led to robust injection site reactions that were occasionally severe and prolonged. Elimination of the montanide reduced injection site reactogenicity but may also have compromised the B-cell responses to the tumor antigen vaccine. Disclosures: Rapoport: Gliknik, Inc: Research Funding. Stadtmauer:Celgene: Consultancy, Speakers Bureau; Millenium: Consultancy, Speakers Bureau. Vogl:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium/Takeda: Consultancy, Research Funding; Otsuka: Consultancy; Acetylon: Research Funding. Strome:Gliknik, Inc: Equity Ownership, Patents & Royalties, Research Funding. Salazar:Oncovir, Inc: Employment. Levine:TxCell: Consultancy, Membership on an entity's Board of Directors or advisory committees; University of Pennsylvania: financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight, financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight Patents & Royalties. June:Novartis: Research Funding, entitled to receive royalties from patents licensed to Novartis, entitled to receive royalties from patents licensed to Novartis Patents & Royalties.

Abstract 717 Background: Chimeric antigen receptors (CARs) combine the antigen recognition domain of an antibody with intracellular signaling domains into a single chimeric protein. CD19 is an ideal target for CARs since expression is restricted to normal and malignant B cells. Inclusion of the CD137 (4-1BB) signaling domain results in potent antitumor activity and in vivo persistence of anti-CD19 CARs in mice. We reported anti-tumor activity of CAR-modified autologous T cells targeted to CD19 (CART19 cells) in 3 patients (pts) with CLL with relatively short follow up (Porter, et al NEJM 2011; Kalos et al Sci Trans Med 2011). We now report on outcomes and longer follow up from 10 pts treated with CART19 cells. Methods: Autologous T cells collected by leukapheresis were transduced with a lentivirus encoding anti-CD19 scFv linked to 4-1BB and CD3-z signaling domains. Gene-modified T cells were expanded and activated ex-vivo by exposure to anti-CD3/CD28 beads. Pts had CLL or ALL with persistent disease after at least 2 previous treatments. Results: 10 pts have received CART19 cells; 9 adults median age 65 yrs (range 51–78) were treated for relapsed, refractory CLL and one 7 yr old was treated for relapsed refractory ALL. CLL pts had received a median of 5 prior regimens (range 2–10) and all had active disease at the time of infusion. 3/9 CLL patients had deletion of the p53 gene. The ALL pt had chemorefractory relapse, having received chemotherapy 6 weeks prior to infusion. All CLL pts received lymphodepleting chemotherapy 4–6 days before infusions (FC, PC or bendamustine, while the ALL pt had an ALC grade 2. CART19 homed to the marrow in the CLL pts and marrow and CSF for the ALL patient with detectable CART19 cells in the CSF (21 lymphs/uL, 78% CAR+) day 23 after infusion. 4/9 evaluable pts achieved CR. (3 CLL, 1 ALL). 2 CLL pts had a PR lasting 3 and 5 months, and 3 pts did not respond. In the 4 pts who achieved CR, maximal expanded cells in the blood were detected at an average of 27 fold higher than the infused dose (range 21–40-fold) with maximal in-vivo expansion between day 10 and 31 post infusion. No patient with CR has relapsed. All pts who responded developed a cytokine release syndrome (CRS) manifested by fever, and variable degrees of nausea, anorexia, and transient hypotension and hypoxia. In responding CLL pts the maximal fold elevation from baseline for IFN-γ was 89–298x, IL-6 6–40x, and IL2R 5– 25x, while no significant elevation in systemic levels of TNFα or IL2 were observed. For the ALL pt, maximal elevations from baseline were: IFNγ: 6040x; IL-6: 988x; IL2R: 56x, while significant elevations in TNFα (17x) and IL2 (163x) were also observed. The timing for maximum cytokine elevation differed but in all cases correlated with peak T cell expansion in the PBMC. 5 pts with CRS required treatment; patient 03 was treated with high dose steroids with resolution of symptoms but only achieved a PR. While steroid treatment had a variable effect on the CRS, we noted that these symptoms were temporally associated with significant elevations in serum IL-6. Accordingly, 4 of these pts were treated with the IL6-receptor antagonist tocilizumab on day 3–10 with prompt resolution of fevers, hypotension and hypoxia. 3 of these patients are evaluable for response and 2 achieved a CR. For the pts in CR, CART19 expression in the blood was documented by flow cytometry at the most recent follow up for each patient: 24 mo (pt 01), 22 mo (pt 02), 3 mo (pt 100), and 2 mo (pt 09). Conclusions: Autologous T cells genetically engineered to express an anti-CD19 scFv coupled to 4-1BB/CD3-z signaling domains can undergo robust in-vivo expansion, persist for at least up to 2 yrs, and can be associated with a significant CRS that responds to anti-cytokine therapy. CART19 cells can induce potent and sustained responses (6/9 responses, 4 CR) for patients with advanced, refractory and high risk CLL and relapsed refractory ALL. Disclosures: Porter: Novatis: Patents & Royalties; Celgene: Honoraria; Genentech: Employment; Pfizer: Research Funding. Off Label Use: The use of CART19 cells to treat CD19+ malignancy and the use of tocilizumab to treat cytokine activation syndrome related to CART19 cells. Kalos:University of Pennsylvania: Employment, Patents & Royalties. Levine:TxCell: Consultancy, Membership on an entity's Board of Directors or advisory committees; University of Pennsylvania: financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight Patents & Royalties. June:Novartis: Research Funding, entitled to receive royalties from patents licensed to Novartis, entitled to receive royalties from patents licensed to Novartis Patents & Royalties.

TPS160 Background: IMCgp100 is a novel biologic comprising a soluble T cell receptor (TCR) fused to an antibody fragment (scFv) being developed for the treatment of metastatic melanoma. The TCR component binds to the melanoma associated antigen (Ag) gp100 which is overexpressed and presented by HLA A2 on melanoma cells. The scFv component activates T cells in physical contact with the target via CD3. Thus, IMCgp100 is expected to bind melanoma cells and stimulate the immune system to attack the target tissue via cytotoxic lymphocyte killing and via stimulation of accessory immune mechanisms.The purpose of this trial is to assess the pharmacodynamic effects of a single intratumoral dose of IMCgp100 on the tumour microenvironment and to establish what local concentration of drug is required for optimal effect. Such data will aid in future trial design and facilitate clinical development. Methods: This 2 stage exploratory study will assess the effects of 2 different doses of IMCgp100 in subjects with advance...

Abstract 784 BACKGROUND: Previously, we showed that adoptive transfer of in vivo vaccine-primed and ex vivo (anti-CD3/anti-CD28) costimulated autologous T cells (ex-T) at day +12 after transplant increased CD4 & CD8 levels at day +42 and augmented vaccine-specific immune responses in pts with myeloma (MM)[Nat Med 2005; 11: 1230-7]. DESIGN: We conducted a phase I/II 2-arm clinical trial in which 54 pts with advanced MM received autografts after high-dose melphalan followed by infusions of ex-T at day +2 after transplant. Pts also received pretransplant and posttransplant immunizations using a pneumococcal conjugate vaccine (PCV) only (ARM B; n = 26) or the PCV plus an HLA-A2 restricted multipeptide tumor antigen vaccine (3 hTERT peptides + 1 survivin peptide + 1 CMV peptide) for HLA-A2+ patients (ARM A; n = 28). After adoptive transfer of 4.26 × 10e10 costimulated T cells (range 1.59-5.0), the median CD3, CD4 and CD8 counts were 4198, 1545 and 2858 cells per microliter at day +14 post-transplant and 16% of pts developed significant autologous GVHD [Clin Cancer Res 2009;15: 4499 – 507]. Here we first report clinical outcomes from this trial and describe several novel observations about immune reconstitution after day +2 T-cell transfers. CLINICAL RESULTS: For the 54 total transplant pts, the median age was 55 (range 37-68), 28 (52%) were male and 21 (39%) were AA while 32 (59%) were Caucasian and 1 (2%) was Asian. 66% had IgG and 28% had IgA paraproteins while 6% excreted light chains only; 41% had abnormal cytogenetics. With a median followup of 1 year (0.25 - 2.5 years) 50 pts (93%) are alive and 31 (57%) remain event-free (EFS). The projected median EFS is 15 mos with no difference between ARMS A and B. Based on the Cox regression analysis, EFS did not correlate significantly to gender, race nor absolute lymphocyte counts (ALC). However, age correlated inversely to EFS with older pts exhibiting a lower EFS (coefficient = -0.0667, p-value = 0.0398). MM responses at day +60 and day +100 did not correlate to EFS, but the response at day +180 did correlate to EFS (p IMMUNOLOGICAL RESULTS: Preliminary results indicated that 6 of 15 pts (40%) in ARM A had positive tetramer responses to hTERT and/or survivin peptides at one or more timepoints after immunization, defined as tetramer staining by flow cytometry > 0.1% (and > 3-fold increase). Based on analysis of the first 36 patients, the mean sum of the antibody responses to 4 of the 7 serotypes of the pneumococcal conjugate vaccine (PCV; serotypes 6B, 14, 19F, 23F) were 83.55 mcg/ml at day +100 and 74.13 mcg/ml at day +180, highly protective levels, compared to 5.17 mcg/ml at enrollment. We also observed several novel features of immune system recovery after early T-cell transfers. Compared to an historical cohort of 103 MM pts who were autografted without ex-T, post-transplant quantitative IgG, IgA and IgM levels at day +180 (and days +60/+100 for IgG and IgA) were significantly higher in the pts who received day +2 T-cell transfers (IgG: 1525 mg/dl vs 1137 mg/dl, p= 0.014; IgA: 264 mg/dl vs 76 mg/dl, p = 0.0029; IgM: 58 mg/dl vs 39 mg/dl, p = 0.029). Furthermore, when IgG recovery was examined for the IgA MM pts only, the IgG level at day +180 was significantly higher in the ex-T trial (mean IgG = 810 mg/dl vs 611 mg/dl, p = 0.0478). Conversely, when IgA recovery was examined for the IgG MM pts only, the IgA level was significantly higher in the ex-T trial at days +60 (mean IgA = 129.82 mg/dl vs 71.70 mg/dl, p = 0.0036), day +100 (mean IgA = 114.43 mg/dl vs 59.44 mg/dl, p = 0.0075) and day +180 (mean IgA = 98.38 mg/dl vs 48.74 mg/dl, p = 0.0037). Remarkably, a pattern of CD8 T-cell “reprogramming” was also observed after day +2 T-cell transfers such that the % of CD8+/CD45RA+ T-cells at day +60 post-transplant was 75% vs 36% in a cohort of MM transplant pts who did not receive ex-T (p< 0.0001). In addition, the log ratio of Teffector/Tregulatory cells was significantly higher among the patients who received early T-cell transfers (2.57 vs. 1.93, p = 0.0066). CONCLUSIONS: Early adoptive transfers of anti-CD3/anti-CD28 costimulated autologous T-cells significantly enhanced post-transplant humoral and cellular immune reconstitution, a pattern which may be associated with better myeloma control and protection from infection. These data may have important implications for efforts to induce clinically significant immune responses to cancer vaccines in the transplant setting. Disclosures: Vonderheide: University of Pennsylvania and Dana Farber Cancer Institute: Patents & Royalties. June:University of Pennsylvania: Patents & Royalties.

Abstract 797 Introduction: Epidemics of influenza A virus strains have been associated with a mortality rate of 0.1% and hospitalization of approximately 200,000 people per year in the United States. The recent pandemic of swine-origin H1N1 has further emphasized the need to protect the population. Patients with multiple myeloma (MM) are particularly vulnerable to flu infection from altered humoral and cellular immunity from the disease as well as from the immunosuppressive chemotherapies, corticosteroids and radiation frequently used for treatment. In particular, high dose melphalan and ASCT, a common and efficacious treatment as part of first-line or salvage therapy for MM, is associated with post-ASCT immune suppression by virtue of low T-cell numbers, poor T-cell function and immune paresis. Despite anti-infection vaccination after ASCT, pneumococcal pneumonia and influenza are common. In an attempt to improve this outcome we previously showed that adoptive transfer of in-vivo PCV vaccine-primed and ex-vivo (anti-CD3/anti-CD28) co-stimulated autologous T cells (aT-cells) early (within 14 days) post-ASCT increased CD4 and CD8 T cell counts and induced pneumococcal conjugate vaccine-directed T and B-cell responses [Rapoport et al, Nature Medicine, 2005]. Patients who did not receive pre-collection vaccination did not show this response despite infusion of co-stimulated T-cells and post-ASCT vaccination. In the current clinical trial we investigated whether pre-harvest flu vaccination would result in a similar improvement in immunity. Methods: We performed a randomized open-label single center study of two influenza vaccine schedules for patients with high-risk MM responding after conventional induction therapy. Of 21 patients enrolled, 11 were randomly assigned to Group X and received pre- and d+14 post-transplant flu vaccine with the commercially available influenza vaccine (Fluzone) produced by Aventis Pasteur. The 10 patients in Group Y received only post-transplant vaccination. All patients received T-cell harvest, high dose melphalan and ASCT and aT-cell infusion. Immunological assessment (T-cell and B-cell subsets, T-cell repertoire, T-ELISPOT, CFSE-CBC, antibody HAI, B-ELISPOT) was conducted d+60, 100 and 180. The primary study endpoint is the immune response to influenza as measured by the serotype-specific influenza antibody response on day 100 using a standard hemagglutination inhibition assay (HAI) optimized for the vaccine administered each year. Results: The median age was 55 (range 37-68), 13 M, 8 F, 18 Caucasian, 2 African American, 1 Hispanic, IgG 57%, IgA 33%, light chain 10%. With a median follow-up of 1 year, 86% (18/21) patients are alive with 48% (10/21) alive in remission. No difference in these parameters was seen between both Groups. HAI titers, however were higher at all three time points (d+60, 100, 180) for Group X when compared to Group Y both for H3N2 (p= 0.04) and for H1N1 (p=0.07). HAI titers for Group Y remained near baseline throughout all time points while Group X peaked day 60 and remained elevated day 180. Analysis of other immune assessment is ongoing and will be presented. Conclusion: Preliminary analysis of this randomized trial of flu vaccine schedule for MM patients undergoing ASCT suggests superior flu immune reconstitution when vaccine is administered to prime autologous T-cells prior ASCT and aT-cell infusion. This result adds to our observation that an approach of vaccine priming and co-stimulated autologous T-cell infusion after high dose melphalan and ASCT for MM augments an otherwise poor response in this patient population to pneumococcal and influenza vaccination. Investigation of this approach as a platform for anti-myeloma immune therapy is ongoing. Disclosures: June: University of Pennsylvania: Patents & Royalties.

Retrospective studies suggest that rapid lymphocyte recovery following autologous stem cell transplants (SCT) may be associated with better outcomes. Previously we showed that adoptive transfer of in-vivo vaccine-primed and ex-vivo (anti-CD3/anti-CD28) costimulated autologous T cells (ex-T) at about day 14 post-transplant increased CD4 and CD8 T cell counts at day 42 post-transplant and induced pneumococcal conjugate vaccine-directed T and B-cell responses [Rapoport et al, Nature Medicine, 2005]. In 2 current studies, we are further investigating the impact of ex-vivo costimulated autologous T cells on vaccine responses after SCT. In the first study, we are investigating whether a similar strategy of pre- and post-transplant immunizations along with an early infusion of vaccine-primed ex-T can induce responses to a putative tumor vaccine composed of 4 HLA-A2-restricted peptides derived from survivin and hTERT in pts undergoing SCT for myeloma. In the second (randomized) trial, the impact of early ex-T on immune recovery and vaccine reponses is being tested in pediatric neuroblastoma pts. Compared to the previous study, two methodologic changes were made: The target number of T cells infused was raised 5-fold to 5 x 1010 (109/kg) T cells were infused on day + 2 to take greater advantage of homeostatic expansion mechanisms. Patients were monitored for delayed hematopoietic recovery because of this switch to early ex-T and the fact that survivin and hTERT are also expressed in hematopoietic stem cells. At the time of submission, 16 adult and 30 pediatric patients have been enrolled on these trials of whom 11 and 21, respectively, are evaluable for post-transplant hematopoietic and T-cell recovery. On the myeloma trial, the mean # of T cells infused was 3.95 x 1010 with 96% viability and a CD4/CD8 ratio of 1.8:1. At day 14 post-transplant, the median CD4 count was 1951/mcl (range 651–7668) and the median CD8 count was 4117/mcl (range 1499–39,354). The median # days to achieve an absolute neutrophil count (ANC) > 500 was 12 (range 11–14) and the median # days to achieve a PLT count >20,000/mcl was 13 days (range 0–28). Similarly, in the pediatric cohort, median CD4 and CD8 counts at day 30 were 1500 and 2100/mcl, respectively, compared to 22 and 14 in a group of pts who did not receive d+2 ex-T, with no impact on engraftment. 1 adult and 3 pediatric pts also developed an “engraftment syndrome” characterized by GHVD-like features with or without fever. The adult pt with day 14 CD4 and CD8 counts of 2,724 and 11,571 cells/mcl had clinical and histologic features of (autologous) gut GVHD. 3 pediatric pts developed pruritic rashes clinically and pathologically indistiguishable from GVHD within 14 d of ex-T infusion, with fever seen in 1. In the adult and 1 pediatric pt, steroid treatment led to complete resolution of symptoms. These combined data sets demonstrate that robust CD4 and CD8 T cells counts can be achieved as early as day 14 post-SCT when adults or children receive ex-T at day +2 post-SCT without exogenous IL-2 or other cytokine support. It appears that a subset of patients develop a T cell “engraftment syndrome” similar to autologous GVHD. The mechanisms responsible for this rapid immune cell recovery are currently under investigation.