Effects of Patisiran, an RNA Interference Therapeutic, on Cardiac Parameters in Patients With Hereditary Transthyretin-Mediated Amyloidosis.

BACKGROUND: Hereditary transthyretin-mediated (hATTR) amyloidosis is a rapidly progressive, multisystem disease that presents with cardiomyopathy or polyneuropathy. The APOLLO study assessed the efficacy and tolerability of patisiran in patients with hATTR amyloidosis. The effects of patisiran on cardiac structure and function in a prespecified subpopulation of patients with evidence of cardiac amyloid involvement at baseline were assessed. METHODS: APOLLO was an international, randomized, double-blind, placebo-controlled phase 3 trial in patients with hATTR amyloidosis. Patients were randomized 2:1 to receive 0.3 mg/kg patisiran or placebo via intravenous infusion once every 3 weeks for 18 months. The prespecified cardiac subpopulation comprised patients with a baseline left ventricular wall thickness ≥13 mm and no history of hypertension or aortic valve disease. Prespecified exploratory cardiac end points included mean left ventricular wall thickness, global longitudinal strain, and N-terminal prohormone of brain natriuretic peptide. Cardiac parameters in the overall APOLLO patient population were also evaluated. A composite end point of cardiac hospitalizations and all-cause mortality was assessed in a post hoc analysis. RESULTS: In the cardiac subpopulation (n=126; 56% of total population), patisiran reduced mean left ventricular wall thickness (least-squares mean difference ± SEM: -0.9±0.4 mm, P=0.017), interventricular septal wall thickness, posterior wall thickness, and relative wall thickness at month 18 compared with placebo. Patisiran also led to increased end-diastolic volume (8.3±3.9 mL, P=0.036), decreased global longitudinal strain (-1.4±0.6%, P=0.015), and increased cardiac output (0.38±0.19 L/min, P=0.044) compared with placebo at month 18. Patisiran lowered N-terminal prohormone of brain natriuretic peptide at 9 and 18 months (at 18 months, ratio of fold-change patisiran/placebo 0.45, P<0.001). A consistent effect on N-terminal prohormone of brain natriuretic peptide at 18 months was observed in the overall APOLLO patient population (n=225). Median follow-up duration was 18.7 months. The exposure-adjusted rates of cardiac hospitalizations and all-cause death were 18.7 and 10.1 per 100 patient-years in the placebo and patisiran groups, respectively (Andersen-Gill hazard ratio, 0.54; 95% CI, 0.28-1.01). CONCLUSIONS: Patisiran decreased mean left ventricular wall thickness, global longitudinal strain, N-terminal prohormone of brain natriuretic peptide, and adverse cardiac outcomes compared with placebo at month 18, suggesting that patisiran may halt or reverse the progression of the cardiac manifestations of hATTR amyloidosis. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01960348.

Phase 3 Multicenter Study of Revusiran in Patients with Hereditary Transthyretin-Mediated (hATTR) Amyloidosis with Cardiomyopathy (ENDEAVOUR).

PURPOSE: The Phase 3 ENDEAVOUR study evaluated revusiran, an investigational RNA interference therapeutic targeting hepatic transthyretin (TTR) production, for treating cardiomyopathy caused by hereditary transthyretin-mediated (hATTR) amyloidosis. METHODS: Patients with hATTR amyloidosis with cardiomyopathy were randomized 2:1 to receive subcutaneous daily revusiran 500 mg (n = 140) or placebo (n = 66) for 5 days over a week followed by weekly doses. Co-primary endpoints were 6-min walk test distance and serum TTR reduction. RESULTS: Revusiran treatment was stopped after a median of 6.71 months; the study Sponsor prematurely discontinued dosing due to an observed mortality imbalance between treatment arms. Eighteen (12.9%) patients on revusiran and 2 (3.0%) on placebo died during the on-treatment period. Most deaths in both treatment arms were adjudicated as cardiovascular due to heart failure (HF), consistent with the natural history of the disease. A post hoc safety investigation of patients treated with revusiran found that, at baseline, a greater proportion of those who died were ≥ 75 years and showed clinical evidence of more advanced HF compared with those who were alive throughout treatment. Revusiran pharmacokinetic exposures and TTR lowering did not show meaningful differences between patients who died and who were alive. Revusiran did not deleteriously affect echocardiographic parameters, cardiac biomarkers, or frequency of cardiovascular and HF hospitalization events. CONCLUSIONS: Causes for the observed mortality imbalance associated with revusiran were thoroughly investigated and no clear causative mechanism could be identified. Although the results suggest similar progression of cardiac parameters in both treatment arms, a role for revusiran cannot be excluded. CLINICAL TRIAL REGISTRATION: NCT02319005.

Correction to: Phase 3 Multicenter Study of Revusiran in Patients with Hereditary Transthyretin-Mediated (hATTR) Amyloidosis with Cardiomyopathy (ENDEAVOUR).

The original article contained incorrect terminology for one of the cardiac measures; throughout the manuscript and supplementary information 'intraventricular septum wall thickness' should have been given as 'interventricular septum wall thickness'. Corrections should also be noted for Tables 1 and 4: in the Table 1 legend 'Low risk - Neither above at baseline' should read 'Low risk - Neither above threshold at baseline'; in Table 4, the rows 'Mild: eGFR > 60 to < 90 ml/min/1.73 m2' and 'Moderate: eGFR > 30 to < 60 ml/min/1.73 m2' should read 'Mild: eGFR ≥ 60 to < 90 ml/min/1.73 m2' and 'Moderate: eGFR ≥ 30 to < 60 ml/min/1.73 m2', respectively. The original article also contained a mistake in the text of the Pharmacokinetics sub-section of Results; 'There were no apparent differences in revusiran Cmax between patients with mild (eGFR: 30 and < 60 ml/min/1.73 m2) or moderate (eGFR: 60 to < 90 ml/min/1.73 m2) renal impairment when compared with patients with normal (eGFR: ≥ 90 ml/min/1.73 m2) renal function at Weeks 0, 26, and 52 (p > 0.20) (Supplementary Fig. 6)' should read 'There were no apparent differences in revusiran Cmax between patients with mild (eGFR: ≥ 60 to < 90 ml/min/1.73 m2) or moderate (eGFR: ≥ 30 and < 60 ml/min/1.73 m2) renal impairment when compared with patients with normal (eGFR: ≥ 90 ml/min/1.73 m2) renal function at Weeks 0, 26, and 52 (p > 0.20) (Supplementary Fig. 6)'.

Clinical Proof of Concept for a Novel Hepatocyte-Targeting GalNAc-siRNA Conjugate.

Advancement of RNAi-based therapeutics depends on effective delivery to the site of protein synthesis. Although intravenously administered, multi-component delivery vehicles have enabled small interfering RNA (siRNA) delivery and progression into clinical development, advances of single-component, systemic siRNA delivery have been challenging. In pre-clinical models, attachment of a triantennary N-acetylgalactosamine (GalNAc) ligand to an siRNA mediates hepatocyte uptake via the asialoglycoprotein receptor enabling RNAi-mediated gene silencing. In this phase 1 study, we assessed translation of this delivery approach by evaluating the safety, tolerability, pharmacokinetics, and pharmacodynamics of a GalNAc-siRNA conjugate, revusiran, targeting transthyretin (TTR). Subjects received a placebo or ascending doses of revusiran subcutaneously ranging from 1.25-10 mg/kg in the single and 2.5-10 mg/kg in the multiple ascending dose phases. Revusiran was generally well tolerated, with transient, mild to moderate injection site reactions the most common treatment-emergent adverse events. Doses of 2.5-10 mg/kg revusiran elicited a significant reduction of serum TTR versus the placebo (p < 0.01), with mean TTR reductions of approximately 90% observed with multiple dosing. These results demonstrate translation of this novel delivery platform, enabling clinical development of subcutaneously administered GalNAc-siRNAs for liver-based diseases.

Serial scanning with technetium pyrophosphate (99mTc-PYP) in advanced ATTR cardiac amyloidosis.

BACKGROUND: Development of noninvasive imaging modalities to quantify amyloid burden over time is an unmet clinical need. Technetium pyrophosphate (99mTc-PYP) scintigraphy is a simple and widely available radiotracer useful to differentiate transthyretin from light-chain amyloidosis in patients with advanced cardiac amyloidosis. We examined the utility of serial 99mTc-PYP scanning to quantify amyloid burden over time in TTR cardiac amyloidosis (ATTR-CA). METHODS AND RESULTS: Twenty subjects with ATTR-CA (10 wild type, 10 mutant) underwent serial 99mTc-PYP planar cardiac imaging. Cardiac retention was assessed both semiquantitatively (visual score 0, no uptake to 3, uptake greater than bone) and quantitatively (region of interest drawn over the heart, copied, and mirrored over the contralateral chest) to calculate a heart-to-contralateral (H/CL) ratio. Index scan mean visual score and H/CL were 3.0 ± 0.2 and 1.79 ± 0.2, respectively, and after an average 1.5 ± 0.5 years follow-up, did not differ, 3.0 ± 0.2, P = .33 and 1.76 ± 0.2, P = .44. H/CL change was minimal, 0.03 ± 0.17, did not correlate with time between scans, r = 0.19, P = .43, and was observed despite obvious clinical progression (increase in troponin ≥ 0.1 ng/mL, BNP ≥ 400 pg/mL, NYHA class, and/or death). CONCLUSIONS: Serial 99mTc-PYP scanning in subjects with advanced ATTR-CA does not show significant changes over an average 1.5 years of follow-up despite obvious clinical progression.

Effect of an RNA interference drug on the synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) and the concentration of serum LDL cholesterol in healthy volunteers: a randomised, single-blind, placebo-controlled, phase 1 trial.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to LDL receptors, leading to their degradation. Genetics studies have shown that loss-of-function mutations in PCSK9 result in reduced plasma LDL cholesterol and decreased risk of coronary heart disease. We aimed to investigate the safety and efficacy of ALN-PCS, a small interfering RNA that inhibits PCSK9 synthesis, in healthy volunteers with raised cholesterol who were not on lipid-lowering treatment. METHODS: We did a randomised, single-blind, placebo-controlled, phase 1 dose-escalation study in healthy adult volunteers with serum LDL cholesterol of 3·00 mmol/L or higher. Participants were randomly assigned in a 3:1 ratio by computer algorithm to receive one dose of intravenous ALN-PCS (with doses ranging from 0·015 to 0·400 mg/kg) or placebo. The primary endpoint was safety and tolerability of ALN-PCS. Secondary endpoints were the pharmacokinetic characteristics of ALN-PCS and its pharmacodynamic effects on PCSK9 and LDL cholesterol. Study participants were masked to treatment assignment. Analysis was per protocol and we used ANCOVA to analyse pharmacodynamic endpoint data. This trial is registered with ClinicalTrials.gov, number NCT01437059. FINDINGS: Of 32 participants, 24 were randomly allocated to receive a single dose of ALN-PCS (0·015 mg/kg [n=3], 0·045 mg/kg [n=3], 0·090 mg/kg [n=3], 0·150 mg/kg [n=3], 0·250 mg/kg [n=6], or 0·400 mg/kg [n=6]) and eight to placebo. The proportions of patients affected by treatment-emergent adverse events were similar in the ALN-PCS and placebo groups (19 [79%] vs seven [88%]). ALN-PCS was rapidly distributed, with peak concentration and area under the curve (0 to last measurement) increasing in a roughly dose-proportional way across the dose range tested. In the group given 0·400 mg/kg of ALN-PCS, treatment resulted in a mean 70% reduction in circulating PCSK9 plasma protein (p<0·0001) and a mean 40% reduction in LDL cholesterol from baseline relative to placebo (p<0·0001). INTERPRETATION: Our results suggest that inhibition of PCSK9 synthesis by RNA interference (RNAi) provides a potentially safe mechanism to reduce LDL cholesterol concentration in healthy individuals with raised cholesterol. These results support the further assessment of ALN-PCS in patients with hypercholesterolaemia, including those being treated with statins. This study is the first to show an RNAi drug being used to affect a clinically validated endpoint (ie, LDL cholesterol) in human beings. FUNDING: Alnylam Pharmaceuticals.

Single-Dose Pharmacokinetics and Pharmacodynamics of Transthyretin Targeting N-acetylgalactosamine-Small Interfering Ribonucleic Acid Conjugate, Vutrisiran, in Healthy Subjects.

Vutrisiran (ALN-TTRsc02) is a liver-directed, investigational, small interfering ribonucleic acid drug for the treatment of transthyretin (TTR)-mediated amyloidosis. This phase I, randomized, single-blind, placebo-controlled, single ascending dose study evaluated the pharmacodynamics, pharmacokinetics, and safety profile of subcutaneously administered vutrisiran (5-300 mg) in healthy subjects (n = 80). Vutrisiran treatment achieved potent and sustained TTR reduction in a dose-dependent manner, with mean maximum TTR reduction of 57-97%, maintained for ≥ 90 days post dose. Vutrisiran was rapidly absorbed (peak plasma concentration 3-5 hours post dose), had a short plasma half-life (4.2-7.5 hours), and plasma concentrations increased in a dose-proportional manner. Pharmacodynamic and pharmacokinetic results were similar in Japanese and non-Japanese subjects. Vutrisiran had an acceptable safety profile; the most common treatment-related adverse event was mild, transient injection site reactions in four (6.7%) vutrisiran-treated subjects. The favorable pharmacokinetic, pharmacodynamic, and safety results observed here support vutrisiran's continued clinical development.

DISCOVERY: prevalence of transthyretin (TTR) mutations in a US-centric patient population suspected of having cardiac amyloidosis.

BACKGROUND: Hereditary transthyretin-mediated amyloidosis (hATTR amyloidosis) is a multisystem disease that presents with polyneuropathy and/or cardiomyopathy. METHODS: DISCOVERY, a multicenter screening study, enrolled patients with clinically suspected cardiac amyloidosis to determine the frequency of transthyretin (TTR) mutations and assess disease characteristics. RESULTS: Of 1007 patients, the majority were from the US (84%), Black/African American (56%), male (63%), and with a mean (standard deviation) age of 65 (13) years. Among 1001 patients with genotyping results, 74 (7%) had a pathogenic TTR mutation (71/836 [8%] from the US). Val122Ile was the most common mutation, found in 11% of Black/African American patients overall; Black/African American ethnicity was an independent predictor of having a pathogenic TTR mutation. Additional independent predictors of such mutations in the total population and Black/African American group were interventricular septum thickness, low electrocardiogram voltage, and age. CONCLUSIONS: Pathogenic TTR mutations occurred in 8% of US patients with suspected cardiac amyloidosis. Most mutations were Val122Ile, almost exclusively found in Black/African American patients. Disease often remains undetected until advanced and difficult to treat, therefore, clinicians should assess at-risk patients for hATTR amyloidosis as early as possible.

msbB deletion confers acute sensitivity to CO2 in Salmonella enterica serovar Typhimurium that can be suppressed by a loss-of-function mutation in zwf.

BACKGROUND: Pathogens tolerate stress conditions that include low pH, oxidative stress, high salt and high temperature in order to survive inside and outside their hosts. Lipopolysaccharide (LPS), which forms the outer-leaflet of the outer membrane in Gram-negative bacteria, acts as a permeability barrier. The lipid A moiety of LPS anchors it to the outer membrane bilayer. The MsbB enzyme myristoylates the lipid A precursor and loss of this enzyme, in Salmonella, is correlated with reduced virulence and severe growth defects that can both be compensated with extragenic suppressor mutations. RESULTS: We report here that msbB (or msbB somA) Salmonella are highly sensitive to physiological CO2 (5%), resulting in a 3-log reduction in plating efficiency. Under these conditions, msbB Salmonella form long filaments, bulge and lyse. These bacteria are also sensitive to acidic pH and high osmolarity. Although CO2 acidifies LB broth media, buffering LB to pH 7.5 did not restore growth of msbB mutants in CO2, indicating that the CO2-induced growth defects are not due to the effect of CO2 on the pH of the media. A transposon insertion in the glucose metabolism gene zwf compensates for the CO2 sensitivity of msbB Salmonella. The msbB zwf mutants grow on agar, or in broth, in the presence of 5% CO2. In addition, msbB zwf strains show improved growth in low pH or high osmolarity media compared to the single msbB mutant. CONCLUSION: These results demonstrate that msbB confers acute sensitivity to CO2, acidic pH, and high osmolarity. Disruption of zwf in msbB mutants restores growth in 5% CO2 and results in improved growth in acidic media or in media with high osmolarity. These results add to a growing list of phenotypes caused by msbB and mutations that suppress specific growth defects.

Phase I trial of VNP40101M (Cloretazine) in children with recurrent brain tumors: a pediatric brain tumor consortium study.

PURPOSE: VNP40101M (Cloretazine), a novel DNA alkylating agent, was evaluated in a phase I study in children with recurrent brain tumors. EXPERIMENTAL DESIGN: VNP40101M was given i.v. daily for 5 consecutive days every 6 weeks for up to eight cycles. Dose escalation was done independently in patients stratified based on intensity of prior therapy (moderately pretreated, stratum I; heavily pretreated, stratum II). Correlative studies included pharmacokinetics and measurement of O(6)-alkylguanine-DNA alkyl transferase levels in peripheral blood mononuclear cells before and after treatment. RESULTS: Forty-one eligible patients (stratum I, 19; stratum II, 22) were enrolled on this study. The dose-limiting toxicity in 35 evaluable patients was myelosuppression, which occurred in 4 of 16 patients in stratum I and 3 of 19 patients in stratum II. Pharmacokinetic studies showed a median terminal half-life of 30 min (range, 14-39.5). The maximum tolerated dose in stratum I and II were 45 and 30 mg/m(2)/d daily for 5 days every 6 weeks, respectively. Peripheral blood mononuclear cells alkylguanine alkyl transferase levels did not decrease significantly after VNP40101M treatment. Central imaging review confirmed that three patients had stable disease for a median of 45 weeks (range, 37-61+) after therapy. CONCLUSIONS: The recommended dose of VNP40101M for phase II studies in children with brain tumors is 45 mg/m(2)/d in moderately pretreated and 30 mg/m(2)/d in heavily pretreated patients when administered for 5 consecutive days every 6 weeks.

Association of Patisiran, an RNA Interference Therapeutic, With Regional Left Ventricular Myocardial Strain in Hereditary Transthyretin Amyloidosis: The APOLLO Study.

Importance: Patients with cardiac amyloidosis demonstrate reduced myocardial strain with associated sparing of the cardiac apex. In the APOLLO randomized clinical trial, patisiran, an RNA interference therapeutic that inhibits transthyretin synthesis, improved left ventricular (LV) global longitudinal strain (LV GLS) compared with placebo in patients with hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy and evidence of cardiac involvement. Objective: To evaluate the treatment association of patisiran with regional LV myocardial strain in cardiac manifestation in hATTR amyloidosis. Design, Setting, and Participants: This exploratory analysis of APOLLO, a randomized, double-blind, placebo-controlled, phase 3, multicenter international clinical trial that was conducted from December 2013 to January 2016, included patients with hATTR amyloidosis with polyneuropathy who were randomized 2:1 to receive patisiran or placebo. The prespecified cardiac subpopulation (126 of 225 [56%]) comprised patients with a baseline LV wall thickness of 13 mm or more and no history of hypertension or aortic valve disease. This post hoc data analysis was performed between September 2018 and January 2019. Intervention: Placebo or patisiran, 0.3 mg/kg, via intravenous infusion once every 3 weeks for 18 months. Main Outcomes and Measures: The association of patisiran with LV regional longitudinal strain at 18 months. Results: Of the 126 patients included in the prespecified cardiac subpopulation, 36 patients (28.6%) received placebo (median [interquartile range] age, 62 [57-72] years) and 90 patients (71.4%) received patisiran (median [interquartile range] age, 60 [54-66] years); 98 (77.8%) were men, 28 (22.2%) were from North America, and 43 (34.1%) were from Western Europe. At baseline, LV GLS was impaired and regional longitudinal strains were lowest in the basal segments with apical sparing. There were no differences in regional longitudinal strains between the treatment groups at baseline. Patisiran improved the absolute GLS (least-squares mean [SE] difference, 1.4% [0.6%]; 95% CI, 0.3%-2.5%; P = .02) compared with placebo at 18 months, with the greatest differential increase observed in the basal region (overall least-squares mean [SE] difference, 2.1% [0.8%]; 95% CI, 0.6%-3.6%; P = .006) and no significant differences in the mid and apical regions among groups. Conclusions and Relevance: Patisiran prevented the deterioration of LV GLS over 18 months, driven primarily by attenuating disease progression in the basal region, suggesting that basal longitudinal strain may be a more sensitive marker of treatment associations with the cardiac manifestation in hATTR amyloidosis and that basal region may be influenced by disease-modifying therapies more than other ventricular regions. Trial Registration: ClinicalTrials.gov identifier: NCT01960348.

A phase II study of cloretazine (VNP40101M), a novel sulfonylhydrazine alkylating agent, in patients with very high risk relapsed acute myeloid leukemia.

Cloretazine (VNP40101M) is a sulfonylhydrazine alkylating agent with significant anti-leukemia activity. A multicenter phase II study of cloretazine was conducted in patients with first relapse of acute myeloid leukemia (AML) following an initial complete remission (CR) of less than 12 months. Cloretazine was given as a single intravenous infusion at a dose of 600 mg/m(2). Fifty-three patients (median age 62 years (18-84), 41 of 44 (93%) evaluable with intermediate or high risk cytogenetics, 32 (60%) with initial CR durations < or =6 months) were treated on study. Two patients (4%) achieved a second CR. Five (9%) patients died within 30 days of receiving cloretazine therapy. Median overall survival (2.3 months) in the study cohort was directly comparable to that of 233 matched patients treated with other single agents. The study cloretazine regimen had minimal activity in a very high risk subset of patients with relapsed AML.

Phase I study of cloretazine (VNP40101M), a novel sulfonylhydrazine alkylating agent, combined with cytarabine in patients with refractory leukemia.

PURPOSE: Cloretazine (VNP40101M) is a novel sulfonylhydrazine alkylating agent with significant antileukemia activity. A phase I study of cloretazine combined with cytarabine (1-beta-d-arabinofuranosylcytosine, ara-C) was conducted in patients with refractory disease. DESIGN: Ara-C was given i.v. at a fixed dose of 1.5 gm/m(2)/d by continuous infusion for 4 days (patients ages <65 years at time of diagnosis) or 3 days (patients ages > or =65 years). Cloretazine was given i.v. over 15 to 60 minutes on day 2 at a starting dose of 200 mg/m(2), with escalation in 100 mg/m(2) increments in cohorts of three to six patients until a maximum tolerated dose was established. The DNA repair enzyme O(6)-alkylguanine DNA alkyltransferase (AGT) was measured at baseline. RESULTS: Forty patients, including 32 with acute myeloid leukemia, received 47 courses of treatment. Complete responses were seen at cloretazine dose levels of > or =400 mg/m(2) in 10 of 37 (27%) evaluable patients, and in this patient subset, AGT activity was significantly lower in patients that responded to treatment than in patients who did not (P < or = 0.027). Dose-limiting toxicities (gastrointestinal and myelosuppression) were seen with 500 and 600 mg/m(2) of cloretazine combined with the 4-day ara-C schedule but not seen with the 3-day schedule. CONCLUSION: The recommended cloretazine dose schedule for future studies is 600 mg/m(2) combined with 1.5 gm/m(2)/d continuous infusion of ara-C for 3 days. The cloretazine and ara-C regimen has significant antileukemic activity. AGT activity may be a predictor of response to cloretazine.

ALN-RSV01 for prevention of bronchiolitis obliterans syndrome after respiratory syncytial virus infection in lung transplant recipients.

BACKGROUND: Respiratory syncytial virus (RSV) infection in lung transplant (LTx) patients is associated with an increased incidence of bronchiolitis obliterans syndrome (BOS). ALN-RSV01 is a small interfering RNA targeting RSV replication that was shown in an earlier Phase 2a trial to be safe and to reduce the incidence of BOS when compared with placebo. METHODS: We performed a Phase 2b randomized, double-blind, placebo-controlled trial in RSV-infected LTx patients to examine the impact of ALN-RSV01 on the incidence of new or progressive BOS. Subjects were randomized (1:1) to receive aerosolized ALN-RSV01 or placebo daily for 5 days. RESULTS: Of 3,985 symptomatic patients screened, 218 were RSV-positive locally, of whom 87 were randomized to receive ALN-RSV01 or placebo (modified intention-to-treat [mITT] cohort). RSV infection was confirmed by central laboratory in 77 patients (ALN-RSV01, n = 44; placebo, n = 33), which comprised the primary analysis cohort (central mITT [mITTc]). ALN-RSV01 was found to be safe and well-tolerated. At Day 180, in ALN-RSV01-treated patients, compared with placebo, in the mITTc cohort there was a trend toward a decrease in new or progressive BOS (13.6% vs 30.3%, p = 0.058), which was significant in the per-protocol cohort (p = 0.025). Treatment effect was enhanced when ALN-RSV01 was started <5 days from symptom onset, and was observed even without ribavirin treatment. There was no significant impact on viral parameters or symptom scores. CONCLUSIONS: These results confirm findings of the earlier Phase 2a trial and provide further support that ALN-RSV01 reduces the risk of BOS after RSV in LTx recipients.

Phase I study of temozolomide and laromustine (VNP40101M) in patients with relapsed or refractory leukemia.

PURPOSE: Although alkylators are known to be effective against some myeloid leukemias, resistance is often mediated via O6-alkylguanine-DNA alkyltransferase (AGT). Temozolomide's inhibition of AGT may sensitize leukemia cells to the novel alkylator laromustine. We conducted a phase I translational study to evaluate the toxicities and estimate the maximum tolerated dose (MTD) of laromustine when administered with temozolomide (TMZ) in patients with hematologic malignancies. PATIENTS AND METHODS: TMZ was delivered twice daily for 5 doses followed by a single infusion of laromustine. The target TMZ dose was the dose that would reliably result in > 90% AGT depletion. Once the target TMZ dose was identified, the laromustine dose was escalated. A total of 35 patients with relapsed/refractory leukemia were treated. RESULTS: Treatment with TMZ 300 mg for 5 doses resulted in > 90% depletion of AGT levels in 5 of 6 patients. The MTD of the combination was established at TMZ 1500 mg and laromustine 300 mg/m2. Three of the 7 patients assayed from cohort 1 achieved > 90% depletion of AGT activity (range, 77%-100% depletion; median, 88%). Five of 6 patients enrolled in cohort 2 achieved > 90% depletion of AGT activity (range, 92%-100% depletion; median, 93.5%). This established that the 300-mg dose of TMZ (1500 mg total) would be maintained in subsequent cohorts. The majority of adverse events were primarily hematologic, with infectious and pulmonary complications also noted. Three (9%) of the patients with previous refractory disease achieved a complete remission, and 5 (14%) of the patients achieved a morphologic, leukemia-free, but persistent hypocellular bone marrow status. CONCLUSION: Laromustine in combination with TMZ is tolerable and manageable at doses that predictably suppress AGT. Reliable TMZ-induced inhibition of AGT was observed in doses that are clinically tolerable. Evidence of antitumor effect was observed with this combination, suggesting that further efficacy studies should be performed.

Single-agent laromustine, a novel alkylating agent, has significant activity in older patients with previously untreated poor-risk acute myeloid leukemia.

PURPOSE An international phase II study of laromustine (VNP40101M), a sulfonylhydrazine alkylating agent, was conducted in patients age 60 years or older with previously untreated poor-risk acute myeloid leukemia (AML). PATIENTS AND METHODS Laromustine 600 mg/m(2) was administered as a single 60-minute intravenous infusion. Patients were age 70 years or older or 60 years or older with at least one additional risk factor-unfavorable AML karyotype, Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2, and/or cardiac, pulmonary, or hepatic comorbidities. Results Eighty-five patients (median age, 72 years; range, 60 to 87 years) were treated. Poor-risk features included age 70 years or older, 78%; adverse karyotype, 47%; PS of 2, 41%; pulmonary disease, 77%; cardiac disease, 73%; and hepatic disease, 3%. Ninety-six percent of patients had at least two risk factors, and 39% had at least four risk factors. The overall response rate (ORR) was 32%, with 20 patients (23%) achieving complete response (CR) and seven (8%) achieving CR with incomplete platelet recovery (CRp). ORR was 20% in patients with adverse cytogenetics; 32% in those age 70 years or older; 32% in those with PS of 2; 32% in patients with baseline pulmonary dysfunction; 34% in patients with baseline cardiac dysfunction; and 27% in 33 patients with at least four risk factors. Twelve (14%) patients died within 30 days of receiving laromustine therapy. Median overall survival was 3.2 months, with a 1-year survival of 21%; the median duration of survival for those who achieved CR/CRp was 12.4 months, with a 1-year survival of 52%. CONCLUSION Laromustine has significant single-agent activity in elderly patients with poor-risk AML. Adverse events are predominantly myelosuppressive or respiratory. Response rates are consistent across a spectrum of poor-risk features.

Cloretazine (VNP40101M), a novel sulfonylhydrazine alkylating agent, in patients age 60 years or older with previously untreated acute myeloid leukemia.

PURPOSE: Cloretazine (VNP40101M) is a sulfonylhydrazine alkylating agent with significant antileukemia activity. A multicenter phase II study of cloretazine was conducted in patients 60 years of age or older with previously untreated acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS). PATIENTS AND METHODS: Cloretazine 600 mg/m2 was administered as a single intravenous infusion. Patients were stratified by age, performance score, cytogenetic risk category, type of AML, and comorbidity. RESULTS: One hundred four patients, median age 72 years (range, 60 to 84 years), were treated on study. Performance status was 2 in 31 patients (30%) and no patient had a favorable karyotype. Forty-seven patients (45%) had cardiac disease, 25 patients (24%) had hepatic disease, and 19 patients (18%) had pulmonary disease, defined as per the Hematopoietic Cell Transplantation-Specific Comorbidity Index, at study entry. The overall response rate was 32%, with 29 patients (28%) achieving complete response (CR) and four patients (4%) achieving CR with incomplete platelet recovery. Response rates in 44 de novo AML patients, 45 secondary AML patients, and 15 high-risk MDS patients were 50%, 11%, and 40%, respectively. Response by cytogenetic risk category was 39% in 56 patients with intermediate cytogenetic risk and 24% in 46 patients with unfavorable cytogenetic risk. Nineteen (18%) patients died within 30 days of receiving cloretazine therapy. Median overall survival was 94 days, with a 1-year survival of 14%; the median duration of survival was 147 days, with a 1-year survival of 28% for those who achieved CR. CONCLUSION: Cloretazine has significant activity and modest extramedullary toxicity in elderly patients with AML or high-risk MDS. Response rates remain consistent despite increasing age and comorbidity.

Transmembrane domain modulates sorting of membrane proteins in Toxoplasma gondii.

Overlapping mechanisms that function simultaneously in the intracellular sorting of mammalian membrane proteins often confound delineation of individual sorting pathways. By analyzing sorting in the evolutionarily simpler organism Toxoplasma gondii, we demonstrate a role for transmembrane domain (TMD) length in modulating the signal-dependent segregation of membrane proteins to distinct intracellular organelles. The dense granule localization of the single pass transmembrane protein GRA4 could be completely rerouted to the Golgi and cell surface simply by replacement of its TMD with that from either vesicular stomatitis virus G or the low density lipoprotein (LDL) receptor. Mutational and biochemical analyses suggested that this effect was not caused by any specific sequence motif or strength of membrane association of the GRA4 TMD. Instead, a property imparted by the vesicular stomatitis virus G or LDL receptor TMDs, both of which are longer than the GRA4 TMD, appeared to be a decisive factor. Indeed, shortening the LDL receptor TMD to a length similar to that of GRA4 resulted in dense granule localization, whereas lengthening the GRA4 TMD resulted in rerouting to the Golgi. From these data, we conclude that although the TMD may not necessarily be a sole determinant in membrane protein sorting, its properties can markedly modulate the utilization of more conventional signal-mediated sorting pathways.