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99 result(s) for "Eflornithine - therapeutic use"
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Nifurtimox-eflornithine combination therapy for second-stage African Trypanosoma brucei gambiense trypanosomiasis: a multicentre, randomised, phase III, non-inferiority trial
Human African trypanosomiasis (HAT; sleeping sickness) caused by Trypanosoma brucei gambiense is a fatal disease. Current treatment options for patients with second-stage disease are toxic, ineffective, or impractical. We assessed the efficacy and safety of nifurtimox-eflornithine combination therapy (NECT) for second-stage disease compared with the standard eflornithine regimen. A multicentre, randomised, open-label, active control, phase III, non-inferiority trial was done at four HAT treatment centres in the Republic of the Congo and the Democratic Republic of the Congo. Patients aged 15 years or older with confirmed second-stage T b gambiense infection were randomly assigned by computer-generated randomisation sequence to receive intravenous eflornithine (400 mg/kg per day, every 6 h; n=144) for 14 days or intravenous eflornithine (400 mg/kg per day, every 12 h) for 7 days with oral nifurtimox (15 mg/kg per day, every 8 h) for 10 days (NECT; n=143). The primary endpoint was cure (defined as absence of trypanosomes in body fluids and a leucocyte count ≤20 cells per μL) 18 months after treatment. Efficacy analyses were done in the intention-to-treat (ITT), modified ITT, and per-protocol (PP) populations. The non-inferiority margin for the difference in cure rates was defined as 10%. This study is registered with ClinicalTrials.gov, number NCT00146627. One patient from the eflornithine group absconded after receiving the first dose, without any type of assessment done, and was excluded from all analyses. In the ITT population, 131 (91·6%) of 143 patients assigned to eflornithine and 138 (96·5%) of 143 patients assigned to NECT were cured at 18 months (difference −4·9%, one-sided 95% CI −0·3; p<0·0001). In the PP population, 122 (91·7%) of 133 patients in the eflornithine group and 129 (97·7%) of 132 in the NECT group were cured at 18 months (difference −6·0%, one-sided 95% CI −1·5; p<0·0001). Drug-related adverse events were frequent in both groups; 41 (28·7%) patients in the eflornithine group and 20 (14·0%) in the NECT group had major (grade 3 or 4) reactions, which resulted in temporary treatment interruption in nine and one patients, respectively. The most common major adverse events were fever (n=18), seizures (n=6), and infections (n=5) in the eflornithine group, and fever (n=7), seizures (n=6), and confusion (n=2) in the NECT group. There were four deaths, which were regarded as related to study drug (eflornithine, n=3; NECT, n=1). The efficacy of NECT is non-inferior to that of eflornithine monotherapy. Since this combination treatment also presents safety advantages, is easier to administer (ie, infusion every 12 h for 7 days vs every 6 h for 14 days), and potentially protective against the emergence of resistant parasites, it is suitable for first-line use in HAT control programmes. Médecins Sans Frontières (Dutch section), Médecins Sans Frontières International, and the Drugs for Neglected Diseases Initiative.
Nifurtimox-Eflornithine Combination Therapy for Second-Stage Trypanosoma brucei gambiense Sleeping Sickness: A Randomized Clinical Trial in Congo
Background. Human African trypanosomiasis caused by Trypanosoma brucei gambiense is a fatal disease. Current treatment options for patients with second-stage disease are either highly toxic or impracticable in field conditions. We compared the efficacy and safety of the nifurtimox-eflornithine drug combination with the standard eflornithine regimen for the treatment of second-stage disease. Methods. A randomized, open-label, active-control, phase III clinical trial comparing 2 arms was conducted at the Sleeping Sickness Treatment Center, which was run by Médecins Sans Frontiéres, in Nkayi, Bouenza Province, Republic of Congo. Patients were screened for inclusion and randomly assigned to receive eflornithine alone (400 mg/kg per day given intravenously every 6 h for 14 days) or eflornithine (400 mg/kg per day given intravenously every 12 h for 7 days) plus nifurtimox (15 mg/kg per day given orally every 8 h for 10 days). Patients were observed for 18 months. The study's outcomes were cure and adverse events attributable to treatment. Results. A total of 103 patients with second-stage disease were enrolled. Cure rates were 94.1% for the eflornithine group and 96.2% for the nifurtimox-eflornithine group. Drug reactions were frequent in both arms, and severe reactions affected 25.5% of patients in the eflornithine group and 9.6% of those in the nifurtimox-eflornithine group, resulting in 2 and 1 treatment suspensions, respectively. There was 1 death in the eflornithine arm and no deaths in the nifurtimox-eflornithine arm. Conclusions. The nifurtimox-eflornithine combination appears to be a promising first-line therapy for second-stage sleeping sickness. If our findings are corroborated by ongoing findings from additional sites (a multicenter extension of this study), the new nifurtimox-eflornithine combination therapy will mark a major and multifaceted advance over current therapies.
Efficacy and safety of eflornithine (CPP-1X)/sulindac combination therapy versus each as monotherapy in patients with familial adenomatous polyposis (FAP): design and rationale of a randomized, double-blind, Phase III trial
Background Molecular studies suggest inhibition of colorectal mucosal polyamines (PAs) may be a promising approach to prevent colorectal cancer (CRC). Inhibition of ornithine decarboxylase (ODC) using low-dose eflornithine (DFMO, CPP-1X), combined with maximal PA export using low-dose sulindac, results in greatly reduced levels of normal mucosal PAs. In a clinical trial, this combination (compared with placebo) reduced the 3-year incidence of subsequent high-risk adenomas by >90 %. Familial Adenomatous Polyposis (FAP) is characterized by marked up-regulation of ODC in normal intestinal epithelial and adenoma tissue, and therefore PA reduction might be a potential strategy to control progression of FAP-related intestinal polyposis. CPP FAP-310, a randomized, double-blind, Phase III trial was designed to examine the safety and efficacy of sulindac and DFMO (alone or in combination) for preventing a clinically relevant FAP-related progression event in individuals with FAP. Methods Eligible adults with FAP will be randomized to: CPP-1X 750 mg and sulindac 150 mg, CPP-1X placebo and sulindac 150 mg, or CPP-1X 750 mg and sulindac placebo once daily for 24 months. Patients will be stratified based on time-to-event prognosis into one of the three treatment arms: best (ie, longest time to first FAP-related event [rectal/pouch polyposis]), intermediate (duodenal polyposis) and worst (pre-colectomy). Stage-specific, “delayed time to” FAP-related events are the primary endpoints. Change in polyp burden (upper and/or lower intestine) is a key secondary endpoint. Discussion The trial is ongoing. As of February 1, 2016, 214 individuals have been screened; 138 eligible subjects have been randomized to three treatment groups at 15 North American sites and 6 European sites. By disease strata, 26, 80 and 32 patients are included for assessment of polyp burden in the rectum/pouch, duodenal polyposis and pre-colectomy groups, respectively. Median age is 40 years; 59 % are men. The most common reasons for screening failure include minimal polyp burden ( n  = 22), withdrawal of consent ( n  = 9) and extensive polyposis requiring immediate surgical intervention ( n  = 9). Enrollment is ongoing. Trial registration This trial is registered at ClinicalTrials.gov ( NCT01483144 ; November 21, 2011) and the EU Clinical Trials Register( EudraCT 2012-000427-41 ; May 15, 2014).
Dual targeting of polyamine synthesis and uptake in diffuse intrinsic pontine gliomas
Diffuse intrinsic pontine glioma (DIPG) is an incurable malignant childhood brain tumor, with no active systemic therapies and a 5-year survival of less than 1%. Polyamines are small organic polycations that are essential for DNA replication, translation and cell proliferation. Ornithine decarboxylase 1 (ODC1), the rate-limiting enzyme in polyamine synthesis, is irreversibly inhibited by difluoromethylornithine (DFMO). Herein we show that polyamine synthesis is upregulated in DIPG, leading to sensitivity to DFMO. DIPG cells compensate for ODC1 inhibition by upregulation of the polyamine transporter SLC3A2. Treatment with the polyamine transporter inhibitor AMXT 1501 reduces uptake of polyamines in DIPG cells, and co-administration of AMXT 1501 and DFMO leads to potent in vitro activity, and significant extension of survival in three aggressive DIPG orthotopic animal models. Collectively, these results demonstrate the potential of dual targeting of polyamine synthesis and uptake as a therapeutic strategy for incurable DIPG. Diffuse intrinsic pontine glioma (DIPG) is an almost incurable malignant childhood brain tumor. Here, the authors show that the polyamine synthetic pathway is activated in DIPG and that the dual targeting of polyamine synthesis and uptake results in prolonged survival in animal models.
New WHO guidelines for treatment of gambiense human African trypanosomiasis including fexinidazole: substantial changes for clinical practice
Human African trypanosomiasis caused by Trypanosoma brucei gambiense is a parasitic infection that usually progresses to coma and death unless treated. WHO has updated its guidelines for the treatment of this infection on the basis of independent literature reviews and using the Grading of Recommendations Assessment, Development and Evaluation methodology. The first-line treatment options, pentamidine and nifurtimox–eflornithine combination therapy, have been expanded to include fexinidazole, an oral monotherapy given a positive opinion from the European Medicines Agency. Fexinidazole is recommended for individuals who are aged 6 years and older with a bodyweight of 20 kg or more, who have first-stage or second-stage gambiense human African trypanosomiasis and a cerebrospinal fluid leucocyte count less than 100 per μL. Nifurtimox–eflornithine combination therapy remains recommended for patients with 100 leucocytes per μL or more. Without clinical suspicion of severe second-stage disease, lumbar puncture can be avoided and fexinidazole can be given. Fexinidazole should only be administered under supervision of trained health staff. Because these recommendations are expected to change clinical practice considerably, health professionals should consult the detailed WHO guidelines. These guidelines will be updated as evidence accrues.
A Phase I Trial of DFMO Targeting Polyamine Addiction in Patients with Relapsed/Refractory Neuroblastoma
Neuroblastoma (NB) is the most common cancer in infancy and most frequent cause of death from extracranial solid tumors in children. Ornithine decarboxylase (ODC) expression is an independent indicator of poor prognosis in NB patients. This study investigated safety, response, pharmacokinetics, genetic and metabolic factors associated with ODC in a clinical trial of the ODC inhibitor difluoromethylornithine (DFMO) ± etoposide for patients with relapsed or refractory NB. Twenty-one patients participated in a phase I study of daily oral DFMO alone for three weeks, followed by additional three-week cycles of DFMO plus daily oral etoposide. No dose limiting toxicities (DLTs) were identified in patients taking doses of DFMO between 500-1500 mg/m2 orally twice a day. DFMO pharmacokinetics, single nucleotide polymorphisms (SNPs) in the ODC gene and urinary levels of substrates for the tissue polyamine exporter were measured. Urinary polyamine levels varied among patients at baseline. Patients with the minor T-allele at rs2302616 of the ODC gene had higher baseline levels (p=0.02) of, and larger decreases in, total urinary polyamines during the first cycle of DFMO therapy (p=0.003) and had median progression free survival (PFS) that was over three times longer, compared to patients with the major G allele at this locus although this last result was not statistically significant (p=0.07). Six of 18 evaluable patients were progression free during the trial period with three patients continuing progression free at 663, 1559 and 1573 days after initiating treatment. Median progression-free survival was less among patients having increased urinary polyamines, especially diacetylspermine, although this result was not statistically significant (p=0.056). DFMO doses of 500-1500 mg/m2/day are safe and well tolerated in children with relapsed NB. Children with the minor T allele at rs2302616 of the ODC gene with relapsed or refractory NB had higher levels of urinary polyamine markers and responded better to therapy containing DFMO, compared to those with the major G allele at this locus. These findings suggest that this patient subset may display dependence on polyamines and be uniquely susceptible to therapies targeting this pathway. Clinicaltrials.gov NCT#01059071.
Eflornithine plus Sulindac for Prevention of Progression in Familial Adenomatous Polyposis
In randomized trial involving 171 adults with familial adenomatous polyposis, the incidence of disease progression was not significantly lower with combination therapy with eflornithine (an inhibitor of ornithine decarboxylase) and sulindac (an NSAID) than with either drug alone.
Approval of DFMO for high-risk neuroblastoma patients demonstrates a step of success to target MYC pathway
The “undruggable” MYC oncoproteins are deregulated in 70% human cancers. The approval of DFMO, an irreversible inhibitor of ornithine oxidase (ODC1) that is a direct transcriptional target of MYC, demonstrates that patients can benefit from targeting MYC activity via an indirect approach. However, the mechanism of action of DFMO needs further studies to understand how it works in post-immunotherapy neuroblastomas. Efforts to develop a more potent and safer drug to block MYC function will continue despite challenges.
Difluoromethylornithine rebalances aberrant polyamine ratios in Snyder–Robinson syndrome
Snyder–Robinson syndrome (SRS) results from mutations in spermine synthase (SMS), which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonia, and seizures. Symptom management is the only treatment. Reduced SMS activity causes spermidine accumulation while spermine levels are reduced. The resulting exaggerated spermidine:spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this imbalance as a therapeutic strategy for SRS. Here we report the repurposing of 2‐difluoromethylornithine (DFMO), an FDA‐approved inhibitor of polyamine biosynthesis, in rebalancing spermidine:spermine ratios in SRS patient cells. Mechanistic in vitro studies demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of spermidine into spermine in hypomorphic SMS cells and induces uptake of exogenous spermine, altogether reducing the aberrant ratios. In a Drosophila SRS model characterized by reduced lifespan, DFMO improves longevity. As nearly all SRS patient mutations are hypomorphic, these studies form a strong foundation for translational studies with significant therapeutic potential. Synopsis Snyder–Robinson syndrome (SRS) is a debilitating, disorder of polyamine metabolism caused by a genetic deficiency in spermine synthase (SMS). This deficiency is characterized by an elevated ratio between two polyamines – spermidine and spermine (SPD/SPM). There is no cure. Difluoromethylornithine (DFMO) reduces the skewed ratio in SRS patient‐derived cell lines, and this effect is facilitated by exogenous SPM (a common dietary component) or a SPM mimetic. The mechanism of action of DFMO in SRS cells includes stimulating conversion of SPD to SPM via the hypomorphic SMS variant and improving polyamine uptake. Sensitivity of the response to DFMO is SMS variant specific. Oral DFMO extends lifespan in a Drosophila model of SRS. Repurposing of DFMO is a promising treatment strategy targeting the molecular changes underlying the SRS phenotype. Graphical Abstract Snyder–Robinson syndrome (SRS) is a debilitating, disorder of polyamine metabolism caused by a genetic deficiency in spermine synthase (SMS). This deficiency is characterized by an elevated ratio between two polyamines – spermidine and spermine (SPD/SPM). There is no cure.
Rationale for, and design of, a clinical trial targeting polyamine metabolism for colon cancer chemoprevention
Polyamine metabolic genes are downstream targets of several genes commonly mutated in colon adenomas and cancers. Inhibitors of ornithine decarboxylase, such as difluoromethylornithine (DFMO), and agents that stimulate polyamine acetylation and export, such as non-steroidal anti-inflammatory drugs (NSAIDS), act at least additively to arrest growth in human cell models and suppress intestinal carcinogenesis in mice. These preclinical studies provided the rationale for colon cancer prevention trials in humans. A Phase IIb clinical study comparing the combination of DFMO and the NSAID sulindac versus placebo was conducted. Endpoints were colorectal tissue polyamine and prostaglandin E2 contents and overall toxicity to participants. Participants in the Phase IIb study served as a vanguard for a randomized, placebo-controlled prospective Phase III trial of the combination of DFMO and sulindac with the primary study endpoint the prevention of colon polyps. Seventy percent of participants will have completed the three years of treatment in December 2006.