ALBERT

Description: Triplet regimens combining an immunomodulatory agent, a proteasome inhibitor (PI), and a steroid are used to treat newly diagnosed and relapsed multiple myeloma (MM). Although ixazomib (Ix), an oral PI with single agent activity, can be combined with lenalidomide (LEN), patients (pts) with relapsed/refractory (R/R) MM are often LEN-refractory. Pomalidomide (POM) has single agent activity in LEN-refractory disease, and both POM and Ix also show activity in poor cytogenetic risk pts. Methods: Primary objectives: 1) determine the maximum tolerated dose (MTD) of Ix in combination with standard dose POM and dexamethasone (DEX), and 2) evaluate the anti-tumor activity of the triplet. The treatment regimen included two dose levels (3 mg and 4 mg) of Ix on days 1, 8, 15; POM 4 mg days 1-21; and DEX 40 mg days 1, 8, 15, 22, of a 28 day cycle. Eligibility: R/R MM after 〉1 prior therapy, LEN-refractory, and ≤ grade(gr) 1 peripheral neuropathy (PN). Pts were treated until progression or unacceptable toxicity. Design: Phase I study utilizing a standard 3+3 design; dose limiting toxicities (DLTs) defined during cycle 1. Results: 32 pts treated, 31 evaluable for toxicity and response. Pts received a median 4 cycles (range 1-13); median follow-up is 5.5 months (range 1.8-21.1). Six pts treated on DL1, 25 treated on DL2, the MTD/Phase II dose (P2D). Median age: 62 years (range 38-84); median time from diagnosis: 3.7 years (range 1.0-8.9); median number prior therapies: 3 (range 1-5); prior transplant: n = 23 (74%); double (LEN/Bortezomib[BOR]) or triple (LEN/BOR/Carfilzomib[CFZ]) refractory: 19 (61%). Phase I: DL1 expanded to n=6 after 1/3 pts experienced DLT (gr3 lung infection); no further DLT seen on DL 1 or 2. Adverse events (AEs) related to POM and/or Ix: ANC decrease Gr1/2 n=11 (35%), Gr3/4 n=10 (32%), platelet decrease Gr1/2 n=9 (29%), lymphocyte decrease Gr1/2 n=8 (26%), Gr3/4 n=11 (35%), PN Gr1/2 n=9 (29%), no Gr3/4. Response: Phase I and II, n=31 pts treated. ORR: 45% (6 VGPR, 8 PR); Clinical Benefit Rate (CBR): 81% (6 VGPR, 8 PR, 3 MR, 8 SD). In the pts with high risk cytogenetics (7[23%] 1q, 3[10%] 17p, 2[6%] t(4;14)) an ORR of 58% (3 VGPR, 4 PR) was seen, and the CBR was 83%. In the double or triple refractory pts, an ORR of 26% and CBR of 79% (1 VGPR, 4 PR, 3 MR, 7 SD) were observed. Conclusions: Ix/POM/DEX is a well-tolerated oral combination therapy, and responses were seen even at DL1 and in high risk patients, including those with poor-risk cytogenetics or advanced refractory disease. Disclosures Kapoor: Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Kumar:Millennium: Consultancy, Research Funding; AbbVie: Research Funding; Glycomimetics: Consultancy; Sanofi: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; BMS: Consultancy; Kesios: Consultancy; Onyx: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding. Lonial:Novartis: Consultancy; BMS: Consultancy; Janssen: Consultancy; Merck: Consultancy; Celgene: Consultancy; Onyx: Consultancy; Novartis: Consultancy; BMS: Consultancy; Celgene: Consultancy; Millenium: Consultancy; Janssen: Consultancy; Onyx: Consultancy. Nathwani:Carevive Systems, Inc.: Research Funding. Forman:Mustang Therpapeutics: Other: Construct licensed by City of Hope. Berdeja:Abbvie, Acetylon, Amgen, Bluebird, BMS, Calithera, Celgene, Constellation, Curis, Epizyme, Janssen, Karyopharm, Kesios, Novartis, Onyx, Takeda, Tragara: Research Funding.

Description: Background: T cells in CTCL are functionally exhausted and are characterized by the expression of immune inhibitory molecules such as PD1 and PD-L1 (Cancer Immunol Res 6; 2018). These findings justify the evaluation of immune checkpoint inhibition to reverse T cell exhaustion in CTCL. We initiated a phase 1/2 clinical trial of lenalidomide and durvalumab to determine the safety and efficacy of this regimen. Durvalumab is a human monoclonal antibody with high affinity and selectivity for PD-L1, targeting exhausted T cells and distinct cells within their environment. Lenalidomide, an oral immunomodulatory drug (IMiD) and analog of thalidomide, has previously shown activity in CTCL (Blood 123; 2014). Durvalumab may restore an anti-tumor immune response, and the combination of durvalumab and lenalidomide may enhance immune checkpoint blockade-induced immune responses. Associations between immune checkpoints, gene expression profile and the clinical efficacy of durvalumab/lenalidomide combination were evaluated. The primary objectives were to determine the recommended phase 2 dose of lenalidomide in combination with durvalumab and safety with primary endpoint of toxicity (using CTCAE 4.03). Secondary end points included objective response rate (ORR) and median duration. Relationships between gene expression profile (GEP), PD-L1 expression, and antitumor activity were exploratory end points. Methods: A Phase 1 portion (NCT03011814) is ongoing to evaluate the safety and tolerability of the durvalumab and lenalidomide combination. Pts are enrolled in sequential cohorts to receive durvalumab (fixed dose at 1500 mg) and dose escalation of lenalidomide (dose level 1 = 10 mg for all cycles; dose level 2 = 10 mg for cycle 1, 15 mg for all subsequent cycles; dose level 3 =10 mg for cycle 1, 15 mg for cycle 2, and 20 mg for all subsequent cycles) to characterize safety, efficacy and antitumor activity. Serial skin samples were collected to assess the impact on the tumor microenvironment and anti-tumor activity. Results: Ten pts. were evaluable for toxicities. Nine patients were evaluable for response with three patients at each dose level. 8 males/2 females, age 29-59 y, with refractory/advanced CTCL, clinical stages IB (1), IIA (3), IIB (4), IIIA (1), and aggressive epidermotropic CD8+ CTCL (1) and a median of prior systemic treatments of 3 (range, 2-4) have been enrolled. Median follow up time was 12 (range, 3-24+) months. No serious AEs or DLTs were observed during the DLT evaluation period (cycles 1-3). The most frequently reported AEs were fatigue (n=7), skin pain (n=4), chills (n=3), anemia (n=3), and leukopenia (4). One grade 3 maculopapular rash (possibly due to lenalidomide) was observed, all other treatment-related AEs were grade 1/2 in severity. Median cycles of treatment were 7 (range, 3-20+) months. Median duration of response was 4 (range, 1- 21+) months. Six pts achieved PR, while 3 pts maintained stable disease. Three pts remain on treatment. Expression panels of several checkpoints (PD1, PD-L1 & ICOS) (Cycle1 Day1 vs Cycle 2 Day15) were analyzed. Detectable levels of PD-L1 but low levels of ICOS are observed in responding pts vs. high PD-L1 and ICOS levels in non-responders. GEP highlights downregulation of TNF-alpha signaling via NFkB, IFN-gamma, and PI3-AKT-mTOR signaling pathways among other pathways. Conclusions: Durvalumab/lenalidomide has significant clinical activity in refractory/advanced CTCL, which will be formally evaluated in the Phase 2 portion. Responses were durable and ongoing, and treatment was well tolerated. Dose escalation is up to lenalidomide 20 mg daily. Our preliminary results from pts on trial demonstrated that immune signatures on skin biopsies at baseline may be predictive of response to checkpoint blockade and yield insights into mechanisms of therapeutic resistance. Disclosures Querfeld: Bioniz: Membership on an entity's Board of Directors or advisory committees, Other: Investigator; Soligenix: Other: Investigator; Celgene: Other: Investigator, Research Funding; City of Hope Cancer Center and Beckman Research Institute: Employment; Medivir: Consultancy; Trillium: Consultancy, Other: Investigator, Research Funding; miRagen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Investigator; Kyowa: Membership on an entity's Board of Directors or advisory committees, Other: Investigator; Eisai: Other: Investigator; Elorac: Other: Investigator, Research Funding; Helsinn: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Investigator. Palmer:Gilead Sciences: Consultancy. Zain:Spectrum: Consultancy; Seattle Genetics: Consultancy.

Description: The combination of venetoclax and hypomethylating agents (HMA) has demonstrated potent activity in acute myeloid leukemia (AML), both in newly diagnosed patients (pts) and those with relapsed/refractory (r/r) disease. We analyzed the association between response to therapy and leukemic somatic mutations, cytogenetics, and other pertinent patient- and leukemia-related features in a large series of newly diagnosed and r/r AML in adults treated with venetoclax in combination with HMA at City of Hope between October 2016 and May 2018. We identified 107 evaluable adults with AML treated with the combination of venetoclax and HMA. Sixty-one (57%) pts had r/r AML at the time of initiating treatment (median prior lines of therapy: 2; range: 1-10), while 46 (43%) were treated in the frontline setting. The median age of pts was 68 years (range: 19-86). AML was de novo in 57 (53%), therapy-related in 23 (21%) and secondary in 27 (25%) pts. Thirty-six (34%) pts had prior exposure to HMA, and 21 (20%) pts had relapsed following prior allogeneic hematopoietic cell transplantation (HCT). The majority of treated pts had unfavorable (52%) or intermediate-risk (39%) AML based on combined cytogenetics and molecular profiles. The most common detected somatic mutations (majority by next generation sequencing) were FLT3 (17%), followed by DNMT3A (15%), RAS and TET2 (each 14%), RUNX1 (13%), TP53 (12%), and IDH1/2 (11%). Most pts received decitabine in combination with venetoclax (N=97, 91%); only 10 (9%) pts received 5-azacitidine together with venetoclax. Complete remission (CR)/CR with incomplete hematologic recovery (CRi) was achieved in 57 (53%) pts after a median of 2 (range 1-4) cycles. For 36 pts who achieved CR/CRi and had available minimal residual disease (MRD) assessment by multicolor flow cytometry (MFC), 23 (64%) became MRD-. CR/CRi was higher in pts carrying favorable- or intermediate-risk AML compared to poor-risk AML (100% vs. 60% vs. 45%, P=0.029). CR/CRi was 48% in those with complex cytogenetics (N = 31), 45% in monosomal karyotype (N = 22), 36% in KMT2A gene rearrangement (N = 11), 74% in normal karyotype (N = 19), and 25% in inversion 3 (N =4). The CR/CRi rate was not significantly different between newly diagnosed or r/r AML (61% vs. 48%, P = 0.17), nor was there a difference associated with AML type (de novo vs. therapy-related vs. secondary, P= 0.26), patient age (〉 or ≤ 65 years) at time of therapy (P = 0.13), prior allogeneic HCT (P = 0.29), prior administration of HMA (P = 0.37) and the type or schedule (5- or 10-day decitabine) of HMA (P = 0.52). In multivariate analysis, only favorable- or intermediate-risk cytogenetics was associated with better CR/CRi (P = 0.036). CR/CRi was also comparable regardless of the presence or absence of various analyzed somatic AML mutations. However, in recursive partitioning analysis of detectable somatic mutations and response to therapy, the combined lack of RAS, TP53 and RUNX1 mutations was linked to an improved rate of CR/CRi. When AML cases were stratified into functional gene alteration subgroups (according to the TCGA data set), there was no significant difference in CR/CRi according to the presence or absence of certain functional genes/fusions. Median overall survival (OS) for all pts was 12.5 months and was 14.6 months for pts who achieved CR/CRi, in contrast to 4.6 months for non-responders (P

Description: INTRODUCTION: Pelareorep is the infusible form of human reovirus (RV). Our single-agent phase 1 RV trial in relapsed multiple myeloma (MM) showed that pelareorep treatment selectively infected MM cells, as viral RNA was found in myeloma cells and not the bone marrow (BM) stroma. However, we did not observe apoptosis. Our ongoing phase 1 trial, which combines the proteasome inhibitor carfilzomib with RV, has demonstrated RV infection, apoptosis, and clinical responses. We investigated the molecular mechanisms behind the role of a PI (carfilzomib) in this setting. RESULTS: In all MM cell lines we tested (n=4), independently from their sensitivity to RV infection (Stiff et al., Mol Cancer Ther, 2016), viral replication and apoptosis was impaired when MM cells were directly exposed to PIs (carfilzomib and bortezomib). When this experiment was repeated in the setting of the bone marrow cellular fraction or peripheral blood mononuclear cells (PBMCs), it had the opposite effect, as the addition of PI to RV increased RV replication and apoptosis in MM cells. When we washed PBMCs after overnight exposure to RV+PI or to either single agent, then added MM cells, we observed higher infection and apoptosis in cancer cells co-cultured with RV+PI compared to levels from PBMCs treated with each of the single agents, suggesting that PIs increase the ability of PBMCs to serve as a reservoir for infectious reovirus. Monocytes (CD14+) can engage in phagocytosis of reovirus (Berkeley et al., Cancer Immunol Res, 2018), and accordingly we found that RV genome and capsid protein production were detected in CD14+ cells, but not in CD14-depleted PBMCs, and increased upon PI treatment compared to that in RV-treated CD14+ cells. Given that the NF-κB complex is a key proinflammatory signaling pathway associated with the early innate-antiviral immune response, and because PIs can block the degradation of the NF-κB inhibitor IκBα upon phosphorylation, we investigated the effect of the specific IκBα inhibitor Bay-11 in RV viral replication. Our data show that either PI or Bay-11 can inhibit RV-induced IκBα phosphorylation and its subsequent degradation upon RV infection in CD14+ cells, an effect associated with higher capsid formation in RV-treated CD14+ cells in combination with PI or Bay-11, compared to levels from RV alone. Cytokine profiling in PBMCs and CD14+ cells treated with RV in combination with either PI or Bay-11 showed a significant decrease in IFN-α and IFN-β (IFNs) levels and a concomitant increase in RV replication, in contrast to levels from RV alone (p

Description: Introduction: 18Fluoro-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is one of the most widely used imaging techniques to detect multiple myeloma (MM). Intracellular FDG uptake depicts in vivo metabolic activity, which can be seen in both malignant and non-malignant cells, resulting in limited sensitivity and specificity. Our group showed preclinically that tracing MM dissemination using a CD38-directed human antibody, daratumumab, that is radioconjugated with copper-64 via the chelator DOTA (64Cu-DOTA-Dara), led to improved sensitivity and specificity over that of FDG (Caserta et al, Blood 2018). Herein, we report the results of a Phase 1 trial (NCT#03311828) designed to 1) assess the safety and feasibility of 64Cu-DOTA-Dara PET/CT and 2) to evaluate and characterize the ability of 64Cu-DOTA-Dara to accurately detect or exclude MM lesions compared with FDG PET/CT. Methods: Patients with biopsy-proven MM and/or a plasmacytoma received an FDG PET/CT scan within 60 days of enrollment. On Day 0, patients were infused with unlabeled ("cold") Dara at one of four dose levels (0 mg, 10 mg, 45 mg, 95 mg) to optimize biodistribution of radioconjugated 64Cu-DOTA-Dara, especially in the liver and the spleen. Within 6 hours of unlabeled Dara administration, patients received 64Cu-DOTA-Dara at a dose of 13.63-16.68 mCi (~5 mg). Whole-body PET scans were obtained at 24 hours and at 48 hours (the latter scan encompassing known tumors). 64Cu-DOTA-Dara standardized uptake values (SUV) were evaluated in MM lesions and normal organs, which were then compared with values from standard FDG PET/CT. Biopsies were performed on accessible discordant lesions. Results: A total of 10 Dara-naïve patients were imaged. Patients were treated with 0 (n=3), 10 (n=3), 45 (n=3), or 95 mg (n=1) of unlabeled Dara. Four patients had newly diagnosed disease, one had biochemical relapse, one had a recurrent plasmacytoma by MRI, and four had possible recurrence by standard PET/CT. No significant adverse events were observed from either cold or 64Cu-DOTA-Dara. With the exception of the one patient with a recurrent plasmacytoma, radiolabeled antibody was eliminated from systemic circulation in subjects analyzed at the first three dose levels within 30 min post injection. In the patient with a recurrent plasmacytoma, the radiolabeled antibody was elevated in the blood for over two days. One newly diagnosed patient had extensive disease by FDG PET and had a biopsy-proven target lesion in the sternum, which had an SUVmax of 14.7 on 64Cu-DOTA-Dara PET/CT vs. 3.3 onFDG PET/CT. A second biopsy from the same patient was taken from a discordant iliac crest lesion (positive for 64Cu-DOTA-Dara but negative for FDG PET/CT) that showed 20-30% MM cell infiltration. In another patient, an iliac crest lesion was 64Cu-DOTA-Dara positive and FDG-negative; biopsy revealed 6% plasmacytosis in the bone. A third patient had an FDG PET/CT positive pleural lesion with an SUVmax of 8.98 and negative on 64Cu-DOTA-Dara (Figure 1A). The lesion did not show recurrence upon biopsy. Furthermore, 64Cu-DOTA-Dara PET/CT yielded superior imaging of bone lesions in the calvarium (Figure 1B). Escalating doses of unlabeled Dara decreased liver and spleen uptake by 64Cu-DOTA-Dara. Conclusions: In this ongoing study, 64Cu-DOTA-Dara PET/CT imaging is to date safe and provides whole body imaging of MM. Further dose escalation of cold Dara (145 mg, 195 mg) is planned to optimize background interference. This modality has the potential to improve sensitivity and specificity over FDG PET/CT scanning in early-stage MM as well as in recurrent disease. Disclosures Krishnan: Celgene, Janssen, Sanofi, BMS: Consultancy; Sutro BioPharma, zPredicta: Consultancy; Amgen, Takeda: Speakers Bureau; Celgene, Z Predicta: Other: Stock Ownership; Takeda: Research Funding. Palmer:Gilead Sciences: Consultancy. Rosenzweig:Celgene, Takeda: Speakers Bureau. Wu:ImaginAb, Inc.: Consultancy, Other: Board Member.

Description: Introduction: Despite significant progress in the treatment of multiple myeloma (MM), the disease remains incurable and typically follows a pattern of multiple responses and relapses. In the relapsed/refractory MM setting (RRMM), outcomes for patients may be particularly discouraging. New treatments that are safe and effective are therefore of urgent need for this population. Since its FDA approval in 1998 for the treatment of rheumatoid arthritis, leflunomide has been used in over 300,000 patients worldwide. Leflunomide is hepatically cleared and has a favorable toxicity profile even when given over long periods. Its primary mechanism of action is inhibition of pyrimidine synthesis by targeting dihydroorotate dehydrogenase, thus achieving anti-proliferative effects on B and T lymphocytes. The anti-neoplastic potential of this agent has been studied in a number of pre-clinical tumor models. Leflunomide's immunoregulatory action may be related to functional inhibition of CD4+ effector T cells, including Th17 cells as well as dysregulation of T regulatory cells (Tregs). We found that leflunomide-treated C57BL/KaLwRij mice engrafted with 5TGM1 cells had more robust expansion of CD8+ cytotoxic T cells and subsequent decrease of CD4+ Tregs compared to untreated mice. We have also noted that leflunomide impairs growth of MM cells at least partly through inhibition of PIM kinases and c-Myc signaling. We present here final results from a phase 1 study of leflunomide in patients with RRMM. Methods: This single center, single agent, phase 1 dose-escalation trial was designed to determine the maximum tolerated dose of leflunomide in patients with RRMM. The trial implemented a modified rolling six phase 1 dose escalation design. The primary objectives were as follows: 1) to determine the maximum tolerated dose and recommended phase 2 dose of leflunomide; 2) to assess the safety and tolerably of leflunomide at each dose level by evaluation of toxicities. Leflunomide was administered at a loading dose of 100 mg daily for the first three days, then daily in 28-day cycles. The starting dose of daily leflunomide was 20 mg daily, with dose escalation in increments of 20 mg/day, up to 60 mg/day. Dose de-escalation in decrements of 10mg/day was planned. Results: A total of 12 patients have been enrolled starting in December 2015 and treated. The median age is 68 (range 48 - 85), and the median number of prior therapies is 5 (range: 3 - 14). Nine patients had prior autologous stem cell transplant. Double refractory (lenalidomide/bortezomib) disease was noted in 9 patients. High-risk cytogenetics were observed in 5 patients including 2 patients with del17p. All 12 subjects were evaluable for toxicity. One subject was not evaluable for response because of non-compliance. Of the eleven patients evaluable for response, the median number of cycles was 3 (range 1- 15). The median follow up was 177 days (range: 42 - 602). Three patients were treated on DL 1 (20 mg) and three on DL3 (40 mg) without incidence of DLT. At DL5 (60 mg), one patient had a DLT with grade III elevation of alanine aminotransferase; an additional three patients were enrolled at this dose level without further DLTs. One out of 12 subjects remains on treatment, 8 patients were removed from study due to disease progression, two due to adverse events (bacteremia at 60 mg, possibly related to study drug and angioedema at 40 mg, not related to study drug) and one from noncompliance. The most common toxicities were hematologic. There were 4 patients with grade 1 or 2 neutropenia on the 20 and 40 mg dose levels and 1 patient with grade 4 lymphopenia on the 40 mg dose. Except for the DLT, all non-hematologic toxicities were ≤ grade 2. Response: Although not all patients were treated at the 60 mg dose, a clinical benefit rate of 90% has been seen, with 9/10 achieving stable disease (SD). The median duration of SD among 9 patients thus far is 56 days (range: 27-401). In the five evaluable patients with high risk cytogenetics, four of them achieved a clinical benefit. Two subjects had SD lasting nearly one year or longer. In this small cohort, no association between dose and benefit was observed. Conclusion: Leflunomide is a safe and well-tolerated oral option for patients with RRMM, with a clinical benefit from single agent dosing. On the basis of our preclinical work showing synergistic inhibition of MM using leflunomide, pomalidomide, and dexamethasone, we plan clinical testing of this drug combination. Disclosures Rosenzweig: Celgene: Speakers Bureau. Krishnan:Janssen: Consultancy, Speakers Bureau; Sutro: Speakers Bureau; Onyx: Speakers Bureau; Takeda: Speakers Bureau; Celgene: Consultancy, Equity Ownership, Speakers Bureau. Forman:Mustang Therapeutics: Other: Licensing Agreement, Patents & Royalties, Research Funding.

Description: Introduction Acute myeloid leukemia (AML) is a highly aggressive form of leukemia with poor long-term survival. Our clinical development of a targeted radiation treatment for relapsed/refractory AML disease led to an impressive two-year overall survival (OS) rate of 41% (Stein et al., 2019) in contrast to