Citations

Abstract T is a Farnesyltransferase inhibitor with clinical activity in elderly adults with newly diagnosed AML who are not candidates for TCC. For adults ≥ age 65 with poor-risk AML, T 600 mg BID for 21 out of every 28–63 days induces complete remissions (CR) in 15%, median duration 7.3 mos, median survival 18 mos. In vitro, T+E exhibits synergistic anti-AML effects. In an attempt to increase CR rates in elderly AML pts, we are conducting a Phase I trial of oral T+E, with escalating doses of both drugs and 14 vs. 21 days of T every 28–63 days (median time to beginning cycle 2 is Day 31, range 29–43). To date, 60 adults ≥ age 70 (median 77, range 71–91) have been treated at 10 dose levels of T (300, 400 or 600 mg BID, 14 or 21 days) + E (100, 150 or 200 mg daily days 1–3 and 8–10) and have received 145 cycles (median 3, range 1–7). A total of 35 (58%) have had secondary AML and 31 (52%) have had adverse cytogenetics. Marrow blast percent was median 55% (range 20–96%), with 75% >30,000 blasts. Nonhematologic toxicities include oropharyngeal mucositis (15% ≥ grade 2), CNS (overall 30%, with 80% of those ≤ grade 2), renal (6%), hyperbilirubinemia (6%), rash (20%) and fatigue (20%). Toxicities occurred across all T+E dose levels tested to date. Documented infections occurred in 16 (27%) pts during cycle 1 and 22/145 (14%) cycles. Twenty six pts (43%) required hospitalization during cycle 1 for median 7 days (range 2–28). Overall hospitalization rate for all cycles was 28% (41/145). Ten pts (17%) died on study: 6 during cycle 1 (4 infection, 1 emphysema, 1 cerebrovascular) and 4 during cycles 2–4 (3 acute myocardial infarctions, 1 ventricular arrhythmia). For 56 evaluable pts, 12 (21%) have achieved CR and 11(20%) have achieved partial remission/hematologic improvement (PR/HI). All pts achieving CR have done so within 2 cycles (9/12 after cycle 1). Eight of 30 pts (27%) receiving T ≥ 400 mg BID have achieved CR. Median age of CR pts is 79 (range 71–86), 8 (67%) have secondary AML, and 5 (42%) have complex cytogenetics. CR durations to date range from 2+ to 13.5+ mos, with median 7+ months. Three of 12 have relapsed at 3, 10, and 11 mos, 2 have been retreated with T+E, and both have achieved 2nd CRs. In sum, the oral regimen of T+E is tolerable and feasible on an outpatient basis for elderly adults with newly diagnosed AML who are not candidates for TCC, with the suggestion of improvement of CR rates over T alone.

Abstract Background: Responses to the novel HDAC inhibitor romidepsin were observed in patients (pts) with T-cell lymphoma in a phase 1 NCI trial. Aims: To evaluate the efficacy and tolerability of romidepsin in the treatment of advanced cutaneous T-cell lymphoma (CTCL). As an exploratory endpoint, to examine the molecular effects of romidepsin in both CTCL and peripheral T-cell lymphoma (PTCL). Methods: This Phase 2, open-label, multi-arm, multicenter study enrolled 71 CTCL pts from the NCI and 9 extramural sites. PTCL pts were also enrolled. Clinical results for pts with CTCL and biomarker analyses for both PTCL and CTCL are presented here; clinical results for the PTCL pts are presented elsewhere. This study is now closed to accrual. Pts with recurrent CTCL (Stages IA-IVB) received romidepsin at 14 mg/m2 as a 4-hr infusion on days 1, 8 and 15 q 28 days. Responses were assessed using a composite endpoint that evaluated overall changes in skin (modified Physicians Global Assessment), lymph nodes, extranodal visceral lesions and abnormal circulating T-cells. Molecular endpoints evaluated in NCI pts were: histone acetylation in peripheral blood mononuclear cells (PBMCs); MDR-1 gene expression in PBMCs and in biopsy samples; and blood fetal hemoglobin levels. Results: 71 pts (48 men and 23 women) with a mean age of 56 yrs (range 28–84) were enrolled and received romidepsin; 63 pts received ≥2 cycles of therapy. Mean number of prior therapies was 3.4 (range 1–10). Objective disease response rates (ORR) are presented in the table. Overall disease control (CR+PR+SD90) was 62% in all pts and 70% in pts who received ≥2 cycles. Target skin lesions were followed and changes were generally similar to overall skin changes. Median duration of response (DOR) was 11 months (mo) and the maximum DOR as of data cut-off was 5.5+ yrs. The most frequent drug-related AEs (all grades, all cycles) were generally mild, including nausea (82%; 4% ≥grade 3), fatigue (73%; 14% ≥ grade 3), electrocardiogram T-wave amplitude decreased (69%, 0% ≥grade 3); hemoglobin decreased (59%, 9% ≥grade 3), and platelet count decreased (59%; 13% ≥grade 3). Six pts died within 30 days of study drug administration: 2 after salvage chemotherapy, 1 with ARDS due to PD, 2 with infection, and 1 of unknown cause; 2 of these deaths were considered possibly related to treatment. An increase in all biomarkers measured was observed, although not in all pts. Correlation between global histone H3 acetylation (AcH3) at the 24-hr time point and Cmax, AUC, and clearance was observed (r = 0.37, 0.36, and −0.44, respectively, p = 0.03). Pts with major responses were more likely to have higher levels of AcH3 at 24 hr. Conclusions: This study demonstrates tolerability and durable clinical benefit (ORR of 35% and median DOR of 11 mo in all pts) of romidepsin in pts with recurrent CTCL. Significant responses were observed at all stages of disease, including an ORR of 32% in all pts with stage ≥IIB and 20% in all pts with stage IV. Time to response was rapid, within 2 mo in most pts, and responses were durable, >6 mo in most pts. Molecular analyses confirmed that romidepsin inhibits its target deacetylases in pts. Increases were not observed in all pts, perhaps reflecting, in part, variable drug exposure or variable response to HDAC inhibition. Correlation of global acetylation with PK parameters suggests that increased drug exposure results in increased global acetylation. All Pts N=71 Pts ≥ 2 cycles N=63 ORR (CR+PR), n (%) 25 (35%) 25 (40%) PR, n (%) 21 (30%) 21 (33%) CR, n (%) 4 (6%) 4 (6%) SD90, n(%) 19 (27%) 19 (30%) Overall disease control (CR+PR+ SD90) 44 (62%) 44 (70%) DOR 11 (1+ mo, 5.5+ yrs) 11 (1+ mo, 5.5+ yrs) OR for pts with stage ≥ IIB, n (%) 20/62 (32%) 20/55 (36%) SD90= stable disease for ≥90 days

Abstract Background: The histone deacetylase (HDAC) inhibitors are a class of epigenetic agents undergoing clinical testing. HDAC inhibitors modulate expression of genes involved in cell cycle regulation, leading to induction of differentiation or apoptosis. Romidepsin, a novel, HDAC inhibitor, has previously demonstrated activity as a single agent in patients (pts) with T-cell lymphoma in a phase 1 NCI study. Aims: To evaluate the efficacy and tolerability of romidepsin in the treatment of advanced PTCL and as an exploratory endpoint, to examine the molecular effects of romidepsin in both PTCL and cutaneous T-cell lymphoma (CTCL). Methods: This Phase 2, open-label, multi-arm, multicenter study enrolled 43 PTCL pts from the NCI and 9 extramural sites. CTCL pts were also enrolled in this study. The clinical results for pts with PTCL are presented here; the clinical results for the pts with CTCL and the biomarker analyses for both PTCL and CTCL are presented elsewhere. This study is now closed to accrual. Pts with relapsed or refractory PTCL or primary cutaneous anaplastic large cell lymphoma were eligible. Pts received romidepsin 14 mg/m2 as a 4-hr infusion on days 1, 8 and 15 every 28 days. Responses were assessed using elements of the IWG criteria and RECIST, as appropriate, for pts with lymph node involvement and extranodal disease. Results: 43 pts (23[53%] men and 20 [47%] women) with a mean age of 58.1 (range: 27 to 84) years were treated with romidepsin. 31 pts received ≥ 2 cycles of therapy. Mean number of prior therapies was 3.9 (range 1 to 12). Objective disease response rates (ORR) are summarized in the table. The mean number of cycles of treatment was 6.8 (range 1–37) and the overall median duration of response was 8.3 months (range 1.6 months to 4.8+ yrs) for all pts. The median duration of response for the 7 pts who achieved CR was 8.5 months (range 4.6 months to 4.8+yrs). The most frequent drug-related AEs (all grades, all cycles) were generally mild and included: nausea (86%; 0% ≥grade 3), fatigue (79%; 0% ≥grade 3), decreased platelets (70%; 7% ≥grade 3), and decreased AGC (63%; 5% ≥grade 3). One death, in a pt with significant cardiovascular disease who had achieved a CR, was considered possibly related to treatment. Conclusions: This study demonstrates tolerability and durable clinical benefit (ORR of 39% and median duration of response of 8.3 months) of romidepsin in pts with recurrent or refractory PTCL. Based on these promising results, a Phase 2B protocol investigating romidepsin in pts with progressive or relapsed PTCL is ongoing at multiple international centers. All Pts N=43 Pts ≥ 2 cycles N=31 ORR (CR+PR), n (%) 17 (39%) 17 (55%) PR, n (%) 10 (23%) 10 (32%) CR, n (%) 7 (16%) 7 (23%)

By sequencing autozygous human populations, we identified a healthy adult woman with lifelong complete knockout of HAO1 (expected ~1 in 30 million outbred people). HAO1 (glycolate oxidase) silencing is the mechanism of lumasiran, an investigational RNA interference therapeutic for primary hyperoxaluria type 1. Her plasma glycolate levels were 12 times, and urinary glycolate 6 times, the upper limit of normal observed in healthy reference individuals (n = 67). Plasma metabolomics and lipidomics (1871 biochemicals) revealed 18 markedly elevated biochemicals (>5 sd outliers versus n = 25 controls) suggesting additional HAO1 effects. Comparison with lumasiran preclinical and clinical trial data suggested she has <2% residual glycolate oxidase activity. Cell line p.Leu333SerfsTer4 expression showed markedly reduced HAO1 protein levels and cellular protein mis-localisation. In this woman, lifelong HAO1 knockout is safe and without clinical phenotype, de-risking a therapeutic approach and informing therapeutic mechanisms. Unlocking evidence from the diversity of human genetic variation can facilitate drug development.

Abstract Abstract 1508 Background: Tipifarnib is an orally bioavailable farnesyltransferase inhibitor with well-established antileukemic activity in a minority of unselected patients with AML. Seeking to identify patients most likely to have tipifarnib-responsive AML, we applied a PCR-based quantitative 2 gene expression signature ratio (RASGRP1:APTX), which had been tested and validated retrospectively as a predictor of response and survival in previous large studies of tipifarnib, as a molecular screening tool for selection of patients to this pilot trial. Objectives: 1) primary: to determine the complete response (CR +CRi) rate in AML patients prospectively selected for tipifarnib treatment on the basis of a 2-gene signature (RASGRP1:APTX ratio) in bone marrow aspirates. 2) secondary: to assess safety, overall survival, and immunophenotypic expression of RASGRP1 on baseline bone marrow blasts for correlation with PCR-based detection. Methods: This was a multicenter, open-label, phase 2 study. Key eligibility criteria included 1) patients with previously untreated AML, age ≥65 years and deemed unsuitable for or refusing traditional induction chemotherapy, and 2) RASGRP1: APTX ratio of ≥5.0 (measured in bone marrow aspirate) based upon qRT-PCR. Other inclusion criteria included: ECOG PS 0–2, adequate end-organ function, and WBC < 30,000/microliter. Treatment consisted of Tipifarnib 300 mg BID × 21 days, with 7 days off. Dose escalation to 600 mg BID following cycle 1 was permitted for patients who had stable disease (SD) after cycle 1. Patients who achieved CR/CRi or PR after 2 cycles were eligible to continue treatment for up to 6 cycles maximum. Results: A total of 62 patients were consented to the trial. Of these, 21 (34%) were eligible based upon the required 2-gene ratio. Assay results were reported within 72 hours for all patients. Median age was 75 years. Fourteen (67%) patients had adverse karyotype and 14 (67%) had secondary AML (including 7 patients who received prior therapy for MDS). Three patients were replaced during cycle 1, due to withdrawal of consent or early unrelated death, such that 18 patients were considered evaluable for response. Median RASGRP1:APTX was 14.8. Two patients (11%) achieved CR and 6 (33%) additional patients had both SD and achievement of ≥50% reduction in bone marrow blasts by completion of cycle 2. Two of these 6 patients also had ≥50% increase in peripheral blood neutrophils or platelets. All 8 patients with CR or SD received at least 2 cycles of therapy. There was no correlation between baseline RASGRP1:APTX ratio and response. Overall, tipifarnib was well tolerated. Early death (≤ 30 days) was observed in only 1 patient (5%). The most common therapy-related non-hematologic toxicities (mainly grade 1–2) included: anorexia (33%), nausea (33%), fatigue (28%), febrile neutropenia (23%) and diarrhea (23%). Due to the trial not meeting its primary endpoint of at least 3 CR/CRi after 2 cycles, accrual to the trial was suspended. Conclusion: Monotherapy with tipifarnib in preselected elderly patients with AML and a RASGRP1:APTX ratio of ≥5 was associated with significant antileukemic activity and good tolerance. Although the primary endpoints during the first stage of the trial were not met, this study demonstrated the ability to rapidly and efficiently execute a biomarker-driven trial in an aggressive malignancy. Given the observed antileukemic activity in this selected population, along with a favorable toxicity and bioavailability profile for chronic dosing, further study of tipifarnib with less rigid endpoints than CR/CRi is warranted. Updated survival and RASGRP1 protein expression data will also be presented. Disclosures: Off Label Use: Tipifarnib in AML. Knoblauch:Johnson & Johnson: Employment. Karkera:Johnson & Johnson: Employment.

Abstract T is a farnesyltransferase inhibitor with clinical activity in elderly adults with newly diagnosed AML who are not candidates for TCC. For adults age ≥ 65 with poor-risk AML, T 600 mg BID for 21 out of 28–63 days induced complete remissions (CR) in 14%, median duration 7.3 mos, median survival 18.3 mos (Lancet JE, et al, Blood109:1387–1394,2007). In vitro, T+E exhibits synergistic anti-AML activity. In an attempt to increase CR rates in elderly AML pts, we conducted a Phase I trial of oral T+E, with escalation of both drugs and 14 vs. 21 days of T every 28–63 days (median 31 days, range 29–50). T+E resulted in a 25% CR rate (21/84 pts), duration 2 – 26+ mos, with best rates achieved with T dose ≥ 400 mg BID for 14 days (Karp JE, et al, Blood108:130a,2006). In the context of this trial, we have conducted longitudinal laboratory studies of changes in DNA damage and apoptosis in AML marrow blasts obtained from 84 patients prior to T+E (Day 0) and on Day 8 of T+E. Blasts were enriched by Ficoll density gradient separation and fixed in 70% ethanol. Persistent, unrepaired DNA damage was quantified by flow cytometry of cells stained with antibody to phosphorylated histone H2AX (γH2AX). Apoptosis was measured by flow cytometry of propidium iodide-stained cells with sub2n DNA content as observed in cell cycle distribution. To date, we have analyzed changes in in vivo γH2AX from 10 pts (4 CR, 6 stable disease or no response, SD/NR). CR pts had a 2-fold increase (range 1.91–2.22) in DNA damage induced by Day 8 of T+E relative to Day 0 values, while patients with SD/NR had no such increase (0–1.06) in DNA damage. Similarly, the apoptotic fraction of the cell cycle distributions of CR patients increase by 2-fold (range 1.2–5.3) for Day 8 marrow blasts. In contrast, changes in apoptosis were widely divergent for SD/NR patients (range 0.2–7.0). Taken together, these preliminary studies on AML marrow blasts obtained prior to and during T+E therapy suggest a possible linkage among induction of DNA damage, apoptotic response, and clinical outcome. Full analysis of all acquired specimens is ongoing.

Abstract Abstract 47 Background In adults with newly diagnosed, poor-risk AML we previously demonstrated that induction therapy with Flavopiridol in combination with Ara-C and Mitoxantrone (FLAM,) in a timed-sequential manner, yields complete remission (CR) rates of 67% and median disease-free survival (DFS) of 13.6 months. These data suggest that FLAM might improve outcomes relative to standard “7+3” in newly diagnosed AML with poor-risk features. Thus, we are conducting a phase II randomized trial comparing the CR rates with FLAM vs. 7+3 induction for all newly diagnosed adult patients with AML with intermediate and poor-risk features. We also previously identified a population of CD34+CD38− cells with intermediate aldehyde dehydrogenase (ALDH) activity that appears to represent a leukemic stem cell (LSC) population. We are examining the effects of FLAM vs. 7+3 in eradicating this LSC population and determining if persistence of LSC's predicts for relapse. Objectives The primary objective is to compare the rate of CR after 1 cycle of FLAM vs. 1 cycle of 7+3. The secondary objectives are to compare toxicities, survival rates, and presence or absence of minimal residual disease (MRD) after both induction regimens. Methods All newly diagnosed adult patients aged 18–70 without favorable risk features were randomized in a 2:1 fashion between FLAM and 7+3 at 90 mg/m2 of Daunorubicin. To achieve balanced randomization, patients were stratified by age, secondary AML and leukocyte count. CD34+ cell subsets were analyzed by flow cytometry for CD38 expression and ALDH activity by Aldefluor. The trial is ongoing. Results To date, 62 patients are evaluable for the primary end point. Demographics and results are depicted in table 1. Patient characteristics were similar in both arms, although there were more patients with poor risk features in the FLAM arm than 7+3. Overall grade > 3 toxicity was similar between both arms. However, there were 3 cases of grade > 3 tumor lysis syndrome (TLS) with FLAM, with 1 death, vs. 0 with 7+3. There were also 3 deaths with FLAM before day 60 vs. 0 with 7+3. CR rate with FLAM was 68% (28/41), with 1 cycle of 7+3 was 48% (10/21) (p = 0.17), and with 2 cycles (7+3 + 5+2) was 52% (11/21). CR rates based on specific risk factors are depicted in table 2. There was a trend toward improved CR rates in patients with adverse genetics with FLAM (p = 0.17). Putative AML LSC's were distinguished from normal hematopoietic stem cells based on ALDH activity. The persistence of putative LSC's in patients after therapy was highly predictive of subsequent clinical relapse. Conclusions Based on the current CR rate of 68%, FLAM holds promise as a therapeutic option for patients with newly diagnosed AML with intermediate and poor risk features. In this preliminary analysis, there is a suggestion that FLAM leads to higher CR rates in patients with adverse genetics than 7+3. Additionally, the detection of MRD consisting of a residual putative LSC population strongly portended subsequent relapse, even in patients without evidence of leukemia. Disclosures: Off Label Use: Flavopiridol (Alvocidib) is an anti-leukemia agent.