ALBERT

Description: Background: Romidepsin is a bicyclic peptide that inhibits Class I and II HDACs. Piekarz et al noted responses to romidepsin in CTCL (ASCO, 2004). This pivotal phase II study sought to confirm the activity. Methods: This single arm, open label study enrolled CTCL (Stages 1B–1VA), including MF and Sézary syndrome (SS) patients (pts) from ∼40 sites in Europe, Russia, Ukraine, Georgia and the US. Pts with biopsy-proven CTCL (centrally reviewed) who failed ≥1 prior systemic therapy received romidepsin at 14 mg/m2 as a 4-hour IV infusion on Days 1, 8, and 15 q 28 days for up to 6 cycles but could continue if deriving benefit. Eligibility criteria included adequate organ function and ECOG PS ≤ 1. Exclusions included significant CV abnormality or treatment with QTc-prolonging or CYP3A4-inhibiting drugs. The primary endpoint is response rate measured by a combination of imaging, circulating malignant T-cell counts and a weighted scoring instrument to determine skin involvement (confirmed by photography). Target accrual of 64 evaluable pts (i.e. received 2 courses) has been reached and the study will close. Results: 92 pts were eligible with 68 evaluable for efficacy per protocol. Responses in evaluable pts are 1 CR, 3 CCRs, 20 PRs, 40 SD and 4 PD for an ORR of 35% (duration 2–21 months). Of pts who received ≥1 dose, the ORR is 26% (24/92) but includes 5 too early to be assessed. Median time to response is 8 weeks (range 4 – 20). Responses by stage at entry in evaluable pts, as available: Stage IB-IIA 7/23 (30%); Stage IIB-IVA 15/37 (41%). In pts with pruritus at baseline i.e. score of ≥ 30 mm on a 100 mm visual analogue scale (VAS), relief of ≥ 30 mm from baseline or a VAS score of 0 (no itching) for at least 2 cycles, was seen in 18/38 pts (47%). In those pts with severe pruritus (VAS score ≥70 mm), 14/24 (58%) experienced relief of itching. Adverse event (AE) data are available for 75 pts. AEs were reported in 54/75 (72%) of dosed pts but Grade (G) 3/4 events in only 12/75 (16%). Most frequent AEs are nausea/vomiting (G2) fatigue (G2/3), myelosuppression (G2/3), and asymptomatic ECG changes (transient mild QTc prolongation and nonspecific ST-T wave abnormalities). Thirteen pts withdrew due to AEs but there were no treatment-related deaths although 4 pts died of PD and 1 from right ventricular failure. Serious AEs considered possibly, probably or likely related to treatment were reported in 12 pts. Of these, 8 had ≥G3 events: tumor lysis, cardiac tamponade, sepsis, constipation, oral candidiasis, dermatitis, hyperglycemia/vomiting/nausea and bradyarrhythmia/atrial fibrillation. Conclusions: This study confirms the efficacy of romidepsin in treatment-refractory CTCL including relief of pruritus and an encouraging response rate with 4 CCR (1 pathology-confirmed). The low rate of discontinuation due to AEs and prolonged treatment duration of some patients illustrate that toxicity has been manageable.

Description: Introduction: MAVORIC was an open-label, multicenter, randomized phase 3 study evaluating the safety and efficacy of mogamulizumab (moga) compared to vorinostat (vori) in patients with mycosis fungoides (MF) or Sézary syndrome (SS) who had failed at least one prior course of systemic therapy (NCT01728805). Primary results have been reported (Kim et al. Lancet Oncol 2018) and were based on a data cutoff date of December 31, 2016. The primary endpoint was progression-free survival (PFS); patients in the moga treatment arm experienced significantly longer PFS compared to patients in the vori treatment arm (median 7.7 months vs 3.1 months; p

Description: cAMP-mediated signaling potentiates glucocorticoid-mediated apoptosis in lymphoid cells, but an effective means by which to take advantage of this observation in the treatment of lymphoid malignancies has not been identified. The PDE4 enzyme family regulates the catabolism of cAMP to AMP in a wide range of tissues. PDE4 inhibitors have recently been submitted for approval for use in asthma and COPD. In leukemic samples from 11 B-CLL patients, rolipram and RO20-1724, two structurally unrelated PDE4 inhibitors, synergized with either hydrocortisone or dexamethasone in inducing B-CLL but not T cell apoptosis. Dose titration studies demonstrated that addition of a PDE4 inhibitor augmented B-CLL apoptosis even when maximally effective doses of either glucocorticoid were utilized. In five patients so analyzed, 10 uM rolipram augmented the induction of apoptosis by 100 uM hydrocortisone by 40 +/− 18%. Using transient transfection of a GRE-luciferase construct with an Amaxa nucleofector technique, we determined that treatment with PDE4 inhibitors augmented glucocorticoid receptor (GR)-mediated GRE transactivation in primary B-CLL cells. Strikingly, inhibition of PKA with the cAMP antagonist Rp-8Br-cAMPS inhibited glucocorticoid-induced apoptosis by 86 +/− 14% in 6 patients so tested and GRE transactivation by 83% in 8 patients so tested. Similarly, treatment with Ht31 peptide, a 23 residue peptide derived from an AKAP that binds with 4.0 nM dissociation constant to PKA RII subunits, also reduced hydrocortisone-induced transactivation. These studies suggest that PKA activity is required for both the ability of glucocorticoids to induce apoptosis and GRE transactivation in B-CLL cells. CCRF-CEM cells, a well-studied model of glucocorticoid and cAMP-induced apoptosis, differed from B-CLL cells in that stimulation of adenylyl cyclase with the diterpene forskolin was required to increase both glucocorticoid-mediated apoptosis and GRE activation, while PDE4 inhibition had no effect. We isolated both dexamethasone-sensitive and dexamethasone-resistant CCRF-CEM clones for these studies and demonstrated that forskolin induced glucocorticoid sensitivity even in the initially dexamethasone resistant clone. 1,9 dideoxyforskolin, a forskolin analogue that does not activate adenylyl cyclase, failed to augment glucocorticoid sensitivity in CCRF-CEM cells. Given the marked discrepancy in the sensitivity of B-CLL cells and CCRF-CEM cells to PDE4 inhibitor-induced augmentation of glucocorticoid apoptosis and GRE transactivation, we next examined the cAMP response and PDE4 isoforms in these two cell types. Inhibition of PDE4 induced cAMP elevation in B-CLL but not CCRF-CEM cells, while forskolin augmented cAMP levels in CCRF-CEM but not B-CLL cells. While rolipram but not forskolin treatment up-regulated 63 and 68 kDa forms of PDE4B (most likely PDE4B2) in B-CLL, forskolin but not rolipram treatment up-regulated 67 and 72 kDa forms of PDE4D (most likely PDE4D1/D2) in CCRF-CEM cells. These studies suggest that PKA is required for and enhances glucocorticoid-induced apoptosis in B-CLL by modulating GR signal transduction and that inhibition of PDE4 in the absence of exogenous adenylyl cyclase activation is a clinically tenable means by which to achieve such PKA activation. Clinical trials that examine whether PDE4 inhibitors enhance the efficacy of glucocorticoid-containing chemotherapy regimens in B-CLL and other lymphoid malignancies are indicated.

Description: Abstract 2902 Treatment of primary chronic lymphocytic leukemia (CLL) cells with PDE4 inhibitors induces apoptosis while comparable treatment of primary human T and B cells from healthy donors does not. PDE4 inhibitor treatment also augments glucocorticoid-induced apoptosis in CLL cells. We now report that PDE4 inhibitor treatment enhances CLL apoptosis induced by DNA damage. Using drug combination analysis, treatment with etoposide and rolipram resulted in a greater than additive apoptotic effect than predicted by a Loewe additivity model at many dose combinations. In order to directly address the role of DNA damage and rule out effects on drug uptake and efflux, we next examined the ability of PDE4 inhibitors to modulate gamma-irradiation-induced apoptosis in CLL. While most patients demonstrated in vitro sensitivity to rolipram and gamma irradiation, a small subset of patients, including those known to be p53 mutant, that lacked a substantial response to ionizing radiation also lacked sensitivity to rolipram (p 〈 0.01). Those patients with intact sensitivity to radiation, demonstrated at least an additive, or greater-than-additive at some doses, effect on apoptosis when PDE4 inhibitor treatment was combined with gamma irradiation treatment (p 〈 0.05 at 1 Gy and 20 mM rolipram). As judged by comet assays, gamma radiation-induced DNA double stranded breaks were repaired within one hour of induction regardless of exposure to rolipram. As judged by Western analysis and flow cytometry, the kinetics of gamma irradiation-induced H2AX phosphorylation, a marker for DNA damage, were not altered by addition of rolipram in a manner that correlated with apoptosis. Finally, rolipram treatment did not further augment levels of p53, p21cip, or phospho-Chk2. These results suggest that PDE4 inhibitors did not alter double strand DNA break repair nor alter upstream radiation-induced p53-mediated signaling events. As PDE4 inhibitors are known to induce CLL apoptosis through a mitochondrial pathway, our current studies are focused on identifying the mechanism by which DNA damage and PDE4 inhibitor signaling pathways converge at the mitochondrion to enhance apoptosis. Regardless of the precise mechanism by which these supra-additive apoptotic effects occur, our study adds credence to the concept that PDE4 inhibitors may prove to be important sensitizing adjuvants in the treatment of human B cell malignancies. Disclosures: No relevant conflicts of interest to declare.

Description: cAMP analogues have long been known to induce apoptosis in specific lymphoid subsets and to augment the apoptotic effect of glucocorticoids. However, a clinically feasible means by which to take advantage of these effects for the treatment of lymphoid malignancies has not previously been identified. Inhibition of type 4 cAMP phosphodiesterases (PDE4) activates cAMP-mediated signaling in many cell types and several PDE4 inhibitors are currently in clinical trials for inflammatory illnesses such as asthma, COPD and psoriasis. We have previously reported that PDE4 inhibitors induce apoptosis in B-CLL and augment the apoptotic effects of glucocorticoids such as dexamethasone. However, the mechanism by which PDE4 inhibitors increase glucocorticoid-induced apoptosis has remained unclear. In gene chip studies, we find that the PDE4 inhibitor rolipram (10 uM) augments transcript levels of glucocorticoid receptor alpha (GRa). A rolipram-induced dose and time-dependent increase in GRa levels was confirmed both by real-time PCR and by Western analysis. In leukemic cells derived from eight B-CLL patients, GRa transcript levels rose over the first four hours to a mean of 4.8 +/− 0.2-fold above baseline and maintained such a fourfold increase for at least 24 hours. An analysis of GRa transcript half-life following actinomycin D treatment demonstrates that rolipram augments transcript levels in B-CLL cells by a transcriptional mechanism. Consistent with this, rolipram treatment augments GRa transcripts derived from promoters 1A and 1C to a greater degree than 1B. Remarkably, rolipram does not augment GRa transcript levels in normal T cells, B cells, monocytes or neutrophils, even in the presence of the adenylate cyclase activator forskolin. Similarly, no increase in GRa transcript levels was observed in leukemic T-CLL cells. As previously reported in B cell lines, treatment of B-CLL cells with dexamethasone reduced GRa transcript levels in a dose-dependent manner. Co-treatment with PDE4 inhibitors maintained GRa transcript levels above basal levels even at the highest dexamethasone concentration tested (1 uM). Finally, we have confirmed the ability of PDE4 inhibitors to augment dexamethasone-induced apoptosis using several PDE4 inhibitors currently in clinical trials for other indications. Our results suggest that co-treatment with PDE4 inhibitors and high-dose dexamethasone may increase leukemic cell GRa levels and augment the apoptotic efficacy of glucocorticoid therapy in B-CLL patients.

Description: Background: Romidepsin is a bicyclic peptide which inhibits Class I and II HDACs. An initial study by Piekarz et al noted frequent responses to romidepsin therapy in patients with CTCL (ASCO, 2004). The aim of the pivotal phase II study reported here is to confirm this clinical activity. Methods: This single arm, open label study is enrolling mycosis fungoides (Stages IB-IVA) or Sezary syndrome patients from 30 centers in the UK, Germany, Poland and the US. Patients with biopsy-proven CTCL (centrally reviewed) that have failed at least one prior systemic therapy receive up to 6 cycles of romidepsin at 14 mg/m2 as a 4-hour IV infusion on Days 1, 8 and 15 q 28 days but may continue therapy if PR or CR is achieved. Eligibility criteria include adequate organ function and ECOG PS less than or equal to 1. Exclusion criteria include significant cardiovascular abnormalities or treatment with QTc-prolonging or CYP3A4-inhibiting drugs. The primary endpoint is response rate as measured by a combination of imaging, circulating cell counts and a scoring instrument to determine average weighted skin involvement. Skin responses are confirmed by standardized photography. Where possible, correlative studies are performed including acetylation status, apoptotic markers and proteomic analyses. Target accrual is 64 evaluable patients. Results: 45 patients have received treatment with 31 evaluable for efficacy. Preliminary results of responses are 1 CCR, 11 PRs, 17 SD and 2 PD for an ORR of 39% (duration 3–12 months). One PR became a CCR after more than 6 courses of treatment. In responding patients, time to response ranges from 1–3 cycles. In those patients with pruritus, relief of at least 30 mm from baseline (on a 100 mm VAS) or a VAS score of 0 (no itching) for at least 2 cycles, was seen in 14/26 patients (54%). Seven (7) patients withdrew with PD and 13 for other reasons. Most frequent toxicities are nausea/vomiting, fatigue, myelosuppression and asymptomatic ECG changes. 5 patients have withdrawn for toxicity and there have been no treatment-related deaths. Conclusions: This study confirms the previously reported efficacy of romidepsin in treatment-refractory CTCL which includes relief of pruritus and a high response rate including one cCR. The low rate of treatment discontinuation due to side-effects and prolonged treatment duration of some patients illustrate that toxicity has been manageable. Accrual continues.

Description: Abstract 1774 A growing body of literature supports the concept that at least a subset of chronic lymphocytic leukemia (CLL) B cell-receptors (BCRs) are reactive with antigens exposed on apoptotic cells. Work done in the autoimmunity field suggests that through their BCRs, autoreactive B cells can internalize RNA and DNA-containing autoantigens, thereby activating endosomal Toll-like receptor (TLR) 7 and TLR9, respectively, with subsequent TLR-mediated signaling, proliferation and cytokine secretion. cAMP signaling modulates inflammatory signaling in immune system cells and our prior studies have shown that PKA, EPAC and CREB-mediated cAMP signaling can be potently induced in CLL cells with inhibitors of the cyclic nucleotide phosphodiesterase (PDE) PDE4 family in the absence of additional exogenous stimulators of adenylate cyclase. We therefore examined the ability of PDE4 inhibitor-mediated cAMP signaling to regulate TLR7 and 9-mediated signaling in CLL cells. Treatment of CLL cells with the TLR7 and 9 agonists R848 and CpG-B oligonucleotide, respectively, induced IRAK1 degradation and activation of three signaling pathways known to be downstream of TLR7 and 9: the transcription factors NFkB and IRF5 as well as the MAP kinase JNK. The prototypic PDE4 inhibitor rolipram inhibited R848-induced TLR7 and CpG-B-induced TLR9 signaling in CLL cells as judged by Western analysis and immunofluorescent studies of NFkB and IRF5 nuclear translocation as well as JNK phosphorylation. Rolipram also blocked R848 and CpG-B-induced CLL proliferation and TNF secretion. In contrast, rolipram augmented R848 and CpG-B-induced CLL IL-10 synthesis, in keeping with prior studies documenting cAMP response elements in the IL-10 promoter. To test whether RNA and/or DNA antigens exposed in apoptotic cells might induce proliferation in CLL cells through BCR-mediated internalization and subsequent activation of TLR7 and TLR9, we irradiated CLL cells and added them in a graded fashion to live autologous CLL cells. Such exposure to irradiated cells undergoing apoptosis drove CLL proliferation in a manner that was sensitive to TLR7 and TLR9 antagonists, IRAK4 kinase inhibitors and the PDE4 inhibitor rolipram. Our work supports the concept that BCR and TLR-driven responses to apoptotic RNA and DNA-containing complexes may drive proliferation in CLL cells and that PDE4 inhibitors and other agents that target TLR signaling may prove to be effective therapeutic agents in this disease. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction Fostamatinib is a first in its class oral inhibitor of spleen tyrosine kinase (Syk) pathway for treatment of adults with immune thrombocytopenia (ITP) with insufficient response to previous treatment. Choice of treatment for relapsed ITP varies greatly according to clinician and patient preference. It is common for patients to switch between available thrombopoietin (TPO) agonists and now fostamatinib. Titration of these agents is often cumbersome and labor intensive; romiplostim in particular requires weekly visits with lab draws and consumes nurse, pharmacy and provider effort. Here we present real world experience with fostamatinib use in an academic medical center. Methods. We retrospectively identified four patients who were prescribed fostamatinib within the past nine months at Boston Medical Center Health System. All patients had a diagnosis of chronic ITP and were previously treated with corticosteroids, intravenous immunoglobulin (IVIG), and rituximab. With respect to previous TPO receptor use, two of four patients had received both eltrombopag and romiplostim. Patients were started on fostamatinib at a dose of 100 mg by mouth twice daily and titrated up to 150 mg by mouth twice daily if platelet counts were 50K at 4 weeks and one patient had a platelet count

Description: Background: CTCL is a primarily indolent, heterogeneous group of non-Hodgkin lymphomas that arise in the skin but can progress to systemic disease (blood, lymph nodes, viscera). For patients who require systemic treatment, nonchemotherapeutic agents are currently preferred, and multiagent chemotherapies are typically reserved for patients with disease that is particularly aggressive or relapsed/refractory to multiple prior systemic therapies. Durable clinical responses are difficult to achieve, and selection of the best treatment following chemotherapy is unclear. Romidepsin is a potent, bicyclic class 1 selective HDAC inhibitor approved by the US Food Drug Administration for treatment of patients with CTCL who had received ≥ 1 prior systemic therapy as well as patients with peripheral T-cell lymphoma who have received ≥ 1 prior therapy. In the pivotal phase 2 study for the treatment of relapsed/refractory CTCL (GPI-04-0001), romidepsin resulted in rapid and durable responses, with an objective response rate (ORR) of 34% (33/96), including 6% (6/96) with complete response (CR), and median duration of response (DOR) of 15 months. Reduction in pruritus (a common and often debilitating symptom of CTCL) with romidepsin treatment was seen in both clinical responders and nonresponders. Here, we present data for patients with prior systemic chemotherapy from GPI-04-0001. Methods: Adult patients with stage IB-IVA CTCL, including mycosis fungoides and Sézary syndrome, in whom ≥ 1 prior systemic therapy had failed received romidepsin 14 mg/m2as a 4-hour intravenous infusion on days 1, 8, and 15 every 28 days for up to 6 cycles; treatment could be extended for patients with stable disease or response. The primary endpoint was ORR (CR + partial response) using a rigorous composite endpoint based on the sum of changes in the skin, lymph nodes, and blood. DOR was a key secondary endpoint, and reduction in pruritus (by patient-assessed 100-mm visual analog scale [VAS]) was analyzed as an additional indicator of clinical benefit. Concomitant use of antipruritic medications (eg steroids, antihistamines) was not allowed. Responses were assessed at patient screening, on day 1 of each treatment cycle, at end-of-study visit, and every 2 months thereafter for patients off study without disease progression (PD). In this analysis, efficacy and safety of romidepsin in patients with CTCL and prior systemic chemotherapy is assessed. Results: Patients (N = 96) had received a median of 2 (range, 1-8) prior systemic therapies, and 73 of 96 patients (76%) had been previously treated with systemic chemotherapy. The most common prior single-agent chemotherapy and multiagent regimens were methotrexate, CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) and COP (CHOP without doxorubicin). Patients with all stages of CTCL (IB-IVA) had been previously treated with chemotherapy, including 10 of 15 patients with stage IB disease and 21 of 25 patients with skin disease only. The ORR in patients with prior chemotherapy was 34% (25/73), including all 6 patients who achieved CR (8%). The median time to response was 57 days, and the median DOR was 15 months, with the longest response ongoing at 19 months. Response rates to romidepsin for patients with 1, 2, 3, or 〉 3 total prior systemic therapies were 32% (8/25), 43% (6/14), 27% (4/15), and 37% (7/19), respectively. The mean best change in pruritus VAS for the 50 patients with prior chemotherapy and moderate to severe pruritus at baseline was −39 mm; 24 of 50 patients (48%) experienced clinically meaningful pruritus reduction, defined as a reduction of ≥ 30 mm for ≥ 2 consecutive treatment cycles. The most common (≥ 10%) treatment-emergent adverse events in patients with prior chemotherapy were nausea (52%), asthenic conditions (51%), anorexia (26%), vomiting (26%), pyrexia (22%), anemia (19%), thrombocytopenia (19%), diarrhea (15%) and headache (15%), and most events were grade 1/2. Conclusions: Patients in the pivotal study of romidepsin for the treatment of relapsed/refractory CTCL were heavily pretreated, and the majority—even those with early-stage disease—had received prior systemic chemotherapy. Romidepsin resulted in durable responses with manageable toxicity in patients with prior chemotherapy, supporting the use of romidepsin irrespective of the number of prior therapies. Disclosures Duvic: Celgene: Consultancy, Research Funding. Kim:Celgene : Advisory Board Other. Robak:Celgene: Research Funding; Gloucester Pharmaceuticals: Research Funding. McCulloch:Celgene, Inc. : Consultancy, Equity Ownership. Waksman:Brightech International, LLC: Consultancy. Whittaker:Millennium Pharmaceuticals: Advisory Board, Advisory Board Other, Consultancy, Honoraria, Research Funding; Actelion: Advisory Board Other, Consultancy.