ALBERT

Description: 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.

Description: In vitro studies have suggested that AML cells are sensitive to treatment with the mammalian target of rapamycin (mTOR) inhibitor, rapamycin. In particular, mTOR inhibition is known to enhance the sensitivity of primary AML cells and AML stem cells to etoposide based chemotherapy leading to inhibition of leukemic SRC activity in NOD/SCID mice. To determine the feasibility of applying this approach in vivo, we performed a Phase I dose escalation study of the mTOR inhibitor sirolimus (rapamycin) with a combination chemotherapy induction regimen in adults with relapsed or refractory non-M3 AML. The purpose of this trial was to determine the safety and dose limiting toxicities of sirolimus and chemotherapy in this patient population. Patients received a loading dose of oral sirolimus on day 1 followed 24 hours later by daily doses of oral sirolimus on days 2–7 plus MEC (mitoxantrone 8 mg/m2/day IV, etoposide 100 mg/m2/day IV, and cytarabine 1000 mg/m2/day IV) on days 1–5. Five sirolimus dose levels were explored by a standard 3+3 design. Sirolimus was studied at loading doses from 3–15 mg and daily doses from 1–5 mg/d. Clinical response was assessed by bone marrow biopsy upon hematologic recovery or day 42, whichever occurred first. 23 adults (14 women, 9 men) of median age 58 (range 22 to 65) with relapsed, refractory, or secondary AML were treated with sirolimus and MEC. Five subjects had antecedent hematologic disorders or prior leukemogenic chemotherapy, 18 had relapsed or refractory disease. Sirolimus was well tolerated and did not increase non-hematologic toxicity of MEC chemotherapy. Asymptomatic, reversible liver transaminase or bilirubin elevations occurred in 4 patients, two of which were 〉 grade 2. One patient with a history of prior cytarabine cerebellar toxicity (unknown at the time of study entry) developed reversible cerebellar ataxia. Three patients died of complications related to bacterial infections during chemotherapy-induced aplasia. Dose limiting toxicity was prolonged myelosuppression at the highest planned dose level and was responsible for one treatment-related death due to infectious complications from unresolved aplasia on study day 119. For the first four dose levels the median time to ANC recovery 〉500/uL among evaluable patients was 27 days (range16–38). Pharmacokinetic data showed that doses of 3 mg and higher consistently achieved rapamycin levels considered therapeutic in solid organ transplantation (4–9.2 ug/L). Bone marrow studies in 2/2 evaluable patients on dose level 4 (12 mg loading dose and 4 mg per day sirolimus) showed inhibition of p70S6 kinase phosphorylation consistent with effective inhibition of mTOR at this dose level. Complete remissions occurred in four patients, all treated for first relapse. Two patients subsequently proceeded to allogeneic transplantation. These results indicate that the combination of mTOR inhibition and chemotherapy is feasible in human AML and establish an appropriate dose for phase II studies to be 12mg loading dose followed by 4 mg daily. Patient recruitment at this dose is ongoing. Confirmation of the efficacy of this regimen, which targets signal transduction in leukemic 〈 stem cells, is planned in a randomized phase II trial at the cooperative group level.

Description: Introduction: FL is generally responsive to conventional-dose chemotherapy but long term disease-free survival (DFS) is uncommon. High-dose chemo-radiotherapy followed by ASCT has the potential to induce remission in this disease but the long-term benefit of this modality remains to be determined. Methods: Between 1990 and 2003, we transplanted 52 pts originally diagnosed with low-grade FL (31 grade 1, 21 grade 2). Twenty-five (48%) had biopsy-proven large cell transformation (FL grade 3 or diffuse large cell lymphoma) before ASCT. The median number of prior therapies was 2 (range: 1 to 7). Prior to ASCT, 45 pts (87%) were responsive to salvage therapy with 20 pts (38%) in CR. Five pts (10%) had chemo-resistant disease at the time of ASCT. High-dose regimens included BCNU-cyclophosphamide-etoposide (31%), melphalan/TBI (27%), and cyclophosphamide/TBI (25%). Thirty-eight pts (73%) received peripheral stem cells (PSCT) and 14 pts (27%) received autologous bone marrow (BM) with 4-hydroxyperoxycyclophosphamide (4-hc) purging in 9 cases (17%). The median age was 49 yrs (range: 29–65). Results: There was 1 treatment-related death during the first 100 days. After ASCT, 36 pts (69%) achieved a CR, 2 (4%) had a PR, and 7 (13%) had stable disease. Among those in CR, 20 (56%) had a CR pre-ASCT, 14 (41%) had a lesser response, and 1 (3%) was chemo-resistant. Median follow-up (f/u) of survivors was 5.3 yrs (range: 1.7 months to 12.4 yrs). The median overall survival (OS) has not yet been reached. The median event-free survival (EFS) is 3.4 yrs (range: 1.7 months to 12.4 yrs). Among complete responders, more than 50% are disease free at last follow-up (range 1.7 months to 12.1 yrs). Variables favorably affecting EFS and OS are age 〈 60 yrs (p = 0.007, 0.015 respectively), achievement of a CR after ASCT (p = 0.002, 0.001), absence of transformation (p = 0.038, 0.017), BM vs. PSCT (p = 0.042, 0.086), and 4-hc BM purging (p = 0.044, 0.059). Number of prior regimens, response prior to ASCT, type of preparative regimen, and addition of TBI, were not significantly associated with EFS, DFS, or OS. In multivariable analysis, achievement of CR after ASCT and age 〈 60 yrs are the only significant predictors of EFS and OS. Adjusted for age, 53% of pts with a CR after ASCT are alive and event-free at last f/u (range: 2.4 months to 12.4 yrs) (Figure 1). In contrast, the median EFS among pts without a CR is 0.5 yrs (range: 1.7 months to 5.3 yrs). Conclusion: ASCT is a reasonable therapeutic approach to FL, resulting in long term EFS for some pts, even with relapsed, refractory and/or transformed disease. In our experience, significant predictors of EFS and OS after ASCT are complete response and age

Description: Introduction: The optimal clinical setting and cell product characteristics for chimeric antigen receptor (CAR) T cell therapy in multiple myeloma (MM) are uncertain. In CLL patients treated with anti-CD19 CAR T cells (CART19), prevalence of an early memory (early-mem) T cell phenotype (CD27+ CD45RO- CD8+) at time of leukapheresis was predictive of clinical response independently of other patient- or disease-specific factors and was associated with enhanced capacity for in vitro T cell expansion and CD19-responsive activation (Fraietta et al. Nat Med 2018). T cell fitness is therefore a major determinant of response to CAR T cell therapy. In an accompanying abstract (Cohen et al.), we report that higher percentage of early-mem T cells and CD4/CD8 ratio within the leukapheresis product are associated with favorable clinical response to anti-BCMA CAR T cells (CART-BCMA) in relapsed/refractory MM. Here, we compare leukapheresis samples from MM patients obtained at completion of induction therapy (post-ind) with those obtained in relapsed/refractory (rel/ref) patients for frequency of early-mem T cells, CD4/CD8 ratio, and in vitro T cell expansion. Methods: Cryopreserved leukapheresis samples were analyzed for the percentage of early-mem T cells and CD4/CD8 ratio by flow cytometry and in vitro expansion kinetics during anti-CD3/anti-CD28 bead stimulation. Post-ind samples were obtained between 2007 and 2014 from previously reported MM trials in which ex-vivo-expanded autologous T cells were infused post-ASCT to facilitate immune reconstitution (NCT01245673, NCT01426828, NCT00046852); rel/ref samples were from MM patients treated in a phase-one study of CART-BCMA (NCT02546167). Results: The post-ind cohort includes 38 patients with median age 55y (range 41-68) and prior exposure to lenalidomide (22), bortezomib (21), dexamethasone (38), cyclophosphamide (8), vincristine (2), thalidomide (8), and doxorubicin (4); median time from first systemic therapy to leukapheresis was 152 days (range 53-1886) with a median of 1 prior line of therapy (range 1-4). The rel/ref cohort included 25 patients with median age 58y (range 44-75), median 7 prior lines of therapy (range 3-13), and previously exposed to lenalidomide (25), bortezomib (25), pomalidomide (23), carfilzomib/oprozomib (24), daratumumab (19), cyclophosphamide (25), autologous SCT (23), allogeneic SCT (1), and anti-PD1 (7). Median marrow plasma cell content at leukapheresis was lower in the post-ind cohort (12.5%, range 0-80, n=37) compared to the rel/ref cohort (65%, range 0-95%). Percentage of early-mem T cells was higher in the post-ind vs rel/ref cohort (median 43.9% vs 29.0%, p=0.001, left figure). Likewise, CD4/CD8 ratio was higher in the post-ind vs rel/ref cohort (median 2.6 vs 0.87, p2 lines of therapy prior to apheresis (n=3) compared to the rest of the cohort (n=35). Conclusion: In MM patients, frequency of the early-mem T cell phenotype, a functionally validated biomarker of fitness for CAR T cell manufacturing, was significantly higher in leukapheresis products obtained after induction therapy compared to the relapsed/refractory setting, as was CD4/CD8 ratio and magnitude of in vitro T cell expansion. This result suggests that CAR T cells for MM would yield better clinical responses at early points in the disease course, at periods of relatively low disease burden and before exposure to multiple lines of therapy. Figure. Figure. Disclosures Garfall: Novartis: Research Funding; Kite Pharma: Consultancy; Amgen: Research Funding; Bioinvent: Research Funding. Cohen:GlaxoSmithKline: Consultancy, Research Funding; Kite Pharma: Consultancy; Oncopeptides: Consultancy; Celgene: Consultancy; Novartis: Research Funding; Poseida Therapeutics, Inc.: Research Funding; Bristol Meyers Squibb: Consultancy, Research Funding; Janssen: Consultancy; Seattle Genetics: Consultancy. Fraietta:Novartis: Patents & Royalties: WO/2015/157252, WO/2016/164580, WO/2017/049166. Davis:Novartis Institutes for Biomedical Research, Inc.: Patents & Royalties. Levine:CRC Oncology: Consultancy; Brammer Bio: Consultancy; Cure Genetics: Consultancy; Incysus: Consultancy; Novartis: Consultancy, Patents & Royalties, Research Funding; Tmunity Therapeutics: Equity Ownership, Research Funding. Siegel:Novartis: Research Funding. Stadtmauer:Janssen: Consultancy; Amgen: Consultancy; Takeda: Consultancy; Celgene: Consultancy; AbbVie, Inc: Research Funding. Vogl:Karyopharm Therapeutics: Consultancy. Milone:Novartis: Patents & Royalties. June:Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Immune Design: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding; Celldex: Consultancy, Membership on an entity's Board of Directors or advisory committees; Immune Design: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding. Melenhorst:Novartis: Patents & Royalties, Research Funding; Incyte: Research Funding; Tmunity: Research Funding; Shanghai UNICAR Therapy, Inc: Consultancy; CASI Pharmaceuticals: Consultancy.

Description: Neurologic toxicity has been observed with anti-CD19 chimeric antigen receptor (CAR) T cells and the anti-CD19 BiTE blinatumomab. Both focal (e.g., cranial nerve palsy) and global (e.g., generalized seizures) abnormalities have been reported, often associated with systemic cytokine release syndrome (CRS) but also observed after recovery from or in absence of CRS. CART-BCMA consists of expanded autologous T cells transduced with a 4-1BB:CD3-zeta-based CAR specific for B Cell Maturation Antigen. Here, we report clinical features and management of a severe neurotoxicity observed on a phase 1 trial of CART-BCMA for multiple myeloma (MM) (NCT02546167). The subject is a 55-year-old female with high-risk IgA lambda MM. At time of CART-BCMA infusion, her MM manifestations included cytopenias and plasmacytomas of the pleura and paravertebral muscles. Bone marrow (BM) was 〉95% BCMA+ plasma cells. Pre-treatment brain MRI showed pachymeningeal thickening and enhancement over the left cerebral convexity, possibly due to extension of calvarial MM lesions. There was no evidence of CNS MM on a neurologist's exam or by CSF cytology. The subject received 2x108 CART-BCMA cells, 40% of the planned dose, over two consecutive days, without lymphodepleting chemotherapy; a third planned infusion was held due to fevers. Over the next 4 days, fevers persisted, hypoxia and delirium developed, and cytopenias worsened. Brain MRI and lumbar puncture on day 4 showed no new abnormalities. Evaluation for infection was negative. These symptoms coincided with rise in serum IL-6 (nl range

Description: Abstract 74 Background: Carfilzomib, a novel proteasome inhibitor (PI), and pomalidomide, an immunomodulatory agent (IMiD), have both demonstrated promising activity as single agents or in combination with dexamethasone in relapsed/refractory multiple myeloma. IMiD+PI combinations including lenalidomide, bortezomib, dexamethasone and lenalidomide, carfilzomib, dexamethasone have had high response rates and good tolerability. We aimed to combine carfilzomib and pomalidomide with dexamethasone (Car-Pom-d) for the first time and hypothesized that this regimen would be highly active in patients with relapsed/refractory multiple myeloma. Here, we report the first findings from the Phase I dose-escalation and expansion portions of the first phase I/II trial of Car-Pom-d in patients with relapsed/refractory multiple myeloma (NCT01464034). Methods: The primary objectives were to determine the maximum tolerated dose (MTD) and the safety/tolerability of Car-Pom-d. Secondary objectives included determination of overall response rate, time to progression, progression free survival, and time to next therapy. All patients had to be refractory to prior lenalidomide, and must have been relapsed/refractory to their most recent therapy. Treatment consisted of 28-day cycles of oral pomalidomide once daily on days 1–21, intravenous (IV) carfilzomib over 30 minutes on days 1, 2, 8, 9, 15, and 16, and oral or IV dexamethasone 40 mg on days 1, 8, 15, and 22. Dose-escalation of carfilzomib started with 27mg/m2 carfilzomib/4mg pomalidomide/40 mg dexamethasone using a standard 3+3 schema based on dose-limiting toxicities (DLTs) occurring in cycle 1. Carfilzomib was initiated at 20 mg/m2for Cycle 1, days 1–2 at all dose levels. Investigators were permitted to adjust the dose of dexamethasone at any point based on their discretion. Adverse events (AEs) were graded by NCI-CTCAE v4. Response was assessed by the modified International Uniform Response Criteria. Results: In the Phase I dose-escalation portion of the trial, a total of 12 patients were enrolled from 6 centers. The median age was 61 years (range 44–78), 67% were male. The median number of prior regimens was 6 (range 2–15), and median time from diagnosis was 5.1 years. Four (33%) patients had prior stem cell transplant, 11 (92%) had prior bortezomib, and all were lenalidomide-refractory. Cytogenetic abnormalities included 5 patients with del(17p), 2 patients with t(4;14), and 1 patient each with del(13), t(11;14), and t(14;16). In these first 12 patients, drug-related AEs occurring in 〉20% of patients included fatigue (42%), anemia (33%), pneumonia (33%), dyspnea (25%), and thrombocytopenia (25%). Six (50%) patients experienced grade ≥3 AEs including 2 incidence each of neutropenia and febrile neutropenia. The MTD was established as the starting dose level (carfilzomib 20/27 mg/m2, pomalidomide 4mg, dexamethasone 40 mg). At this dose, 1 of 6 patients experienced a protocol-defined DLT of febrile neutropenia. At dose level 2 (carfilzomib 20/36 mg/m2, pomalidomide 4 mg, dexamethasone 40 mg), 2 of 6 patients experienced DLTs, consisting of grade 4 thrombocytopenia and grade 3 rash. All 12 patients were response evaluable with 2 very good partial response (VGPR), 4 partial response (PR), 2 minor response (MR), 2 stable disease (SD), and 2 progressive disease (PD) for a ≥ MR rate of 67%. The 6 month progression free survival was 70% (95% CI: 37 to 90%). Of the 5 patients with del(17p), 1 achieved VGPR, 2 achieved PR, 1 achieved SD. We then enrolled an expansion cohort of 20 patients from 8 centers resulting in a total study population of 32 patients, with 25 still receiving treatment. Three patients have died, all from progressive multiple myeloma. Early response assessments in 27 out of 32 patients show 2 VGPR, 7 PR, 6 MR, 8 SD, and 4 PD for a ≥MR rate of 56%. Conclusions: The Car-Pom-d regimen is well tolerated and achieves a high response rate in a heavily pre-treated, lenalidomide-refractory population with prior bortezomib exposure. Importantly, we have seen responses in patients with poor risk cytogenetics, specifically del (17p). We are beginning enrollment in a larger phase 2 cohort, and updated safety and efficacy data for all patients will be presented at the meeting. Disclosures: Shah: Celgene: Consultancy; Onyx: Consultancy; Novartis: Consultancy; Array: Consultancy. Stadtmauer:Celgene: Consultancy, Speakers Bureau; Millennium: Consultancy, Speakers Bureau. Abonour:Celgene: Honoraria, Speakers Bureau; Millenium: Honoraria, Speakers Bureau. Cohen:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Bensinger:Onyx: Research Funding; Celgene: Consultancy, Research Funding, Speakers Bureau. Gasparetto:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kaufman:Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy. Lentzsch:Celgene: Consultancy, Research Funding. Vogl:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium/Takeda: Consultancy, Research Funding; Otsuka: Consultancy; Acetylon: Research Funding. Orlowski:Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Research Funding. Durie:Onyx: Consultancy; Celgene: Consultancy; Millenium: Consultancy; Amgen: Consultancy.