Reducing acetylated tau is neuroprotective in brain injury.

Traumatic brain injury (TBI) is the largest non-genetic, non-aging related risk factor for Alzheimer's disease (AD). We report here that TBI induces tau acetylation (ac-tau) at sites acetylated also in human AD brain. This is mediated by S-nitrosylated-GAPDH, which simultaneously inactivates Sirtuin1 deacetylase and activates p300/CBP acetyltransferase, increasing neuronal ac-tau. Subsequent tau mislocalization causes neurodegeneration and neurobehavioral impairment, and ac-tau accumulates in the blood. Blocking GAPDH S-nitrosylation, inhibiting p300/CBP, or stimulating Sirtuin1 all protect mice from neurodegeneration, neurobehavioral impairment, and blood and brain accumulation of ac-tau after TBI. Ac-tau is thus a therapeutic target and potential blood biomarker of TBI that may represent pathologic convergence between TBI and AD. Increased ac-tau in human AD brain is further augmented in AD patients with history of TBI, and patients receiving the p300/CBP inhibitors salsalate or diflunisal exhibit decreased incidence of AD and clinically diagnosed TBI.

Hereditary Transthyretin Amyloidosis and the Impact of Classic and New Treatments on Kidney Function: A Review.

Hereditary transthyretin amyloidosis (ATTRv) is a rare, progressive, and life-threatening disease caused by misfolded transthyretin (TTR) proteins that aggregate as abnormal amyloid fibrils and accumulate throughout the body. The kidney is one of the main organs affected in amyloid light chain (AL) amyloidosis and ATTRv amyloidosis. The most common clinical presentation is proteinuria, which consists mainly of albumin; this is the first step in the natural history of ATTRv nephropathy. Not all TTR mutations are equal in terms of ATTRv kidney involvement. Kidney involvement in ATTRv itself is difficult to define, given the numerous associated confounding factors. There are several treatments available to treat ATTRv, including orthotopic liver transplant (OLT), which is the classic treatment for ATTRv. However, we should be careful regarding the use of calcineurin inhibitors in the setting of OLT because these can be nephrotoxic. New treatments for amyloidosis may have an impact on kidney function, including drugs that target specific pathways involved in the disease. Tafamidis and diflunisal, which are TTR stabilizers, patisiran (RNA interference agent), and inotersen (antisense oligonucleotide inhibitor) have been shown to reduce TTR amyloid. Tafamidis and patisiran are medications that have reduced the progression of kidney disease in amyloidosis, but inotersen and diflunisal may damage kidney function.

Two Small Molecule Drugs with Topical Applications, Diflunisal and Naphazoline, and Their Potentially Toxic Photodegradants: Analysis by Chemical and Biological Methods.

Because of their topical application in patients and meaningful UV/VIS absorptive properties, the degradation and potential toxicity under irradiation of diflunisal (DIF) and naphazoline (NAF) were studied. In addition, the impact of pH on their photostability was examined, showing the highest degradation of acidic DIF at pH 1 and 13 and the highest degradation of basic NAF at pH below 7. An LC-UV analysis and chemical tests showed the first-order kinetics for their degradation and generation of reactive oxygen species (ROS). A UPLC-HRMS/MS analysis allowed us to identify four degradants of DIF (from DD-1 to DD-4) and six degradants of NAF (from ND-1 to ND-6). When Toxtree software was used, a high class III of toxicity was observed for DD-2, DD-3, and DD-4, and for all the NAF degradants. Furthermore, the ND-2 product, i.e., 2-[(1-methylnaphthalen-2-yl)methyl]-4,5-dihydro-1H-imidazole, was shown to present medium mutagenic and high tumorigenic effects according to OSIRIS Property Explorer. In addition, two in vitro tests on BALB/c 3T3 mouse fibroblasts showed a phototoxic effect of DIF and NAF at the lowest concentrations tested, i.e., 5 µg/mL. Thus, our present results could be useful to design further phototoxicity studies for DIF and NAF to minimize the risk of phototoxicity due to their photodegradation.

The use of diflunisal for transthyretin cardiac amyloidosis: a review.

Transthyretin cardiac amyloidosis (ATTR-CM) is caused by the accumulation of misfolded transthyretin (TTR) protein in the myocardium. Diflunisal, an agent that stabilizes TTR, has been used as an off-label therapeutic for ATTR-CM. Given limited data surrounding the use of diflunisal, a systematic review of the literature is warranted. We searched the PubMed, MEDLINE, and Embase databases for studies that reported on the use of diflunisal therapy for patients with ATTR-CM. We included English language studies which assessed the effect of diflunisal in adult patients with ATTR-CM who received diflunisal as primary treatment and reported clinical outcomes with emphasis on studies that noted the safety and efficacy of diflunisal in cardiac manifestations of ATTR amyloidosis. We excluded studies which did not use diflunisal therapy or used diflunisal therapy for non-cardiac manifestations of TTR amyloidosis. We also excluded case reports, abstracts, oral presentations, and studies with fewer than 10 subjects. Our search yielded 316 records, and we included 6 studies reporting on 400 patients. Non-comparative single-arm small non-randomized trials for diflunisal comprised 4 of the included studies. The 2 studies that compared diflunisal versus no treatment found improvements in TTR concentration, left atrial volume index, cardiac troponin I, and global longitudinal strain. Overall, diflunisal use was associated with decreased mortality and number of orthotopic heart transplant in ATTR-CM patients. Although a smaller number of patients had to stop treatment due to gastrointestinal side effects and transient renal dysfunction, there were no severe reactions reported in the studies included in our review. This systematic review supports the use of diflunisal for ATTR-CM. Additional long-term analyses and randomized clinical trials are needed to confirm these results.

Treatment With Diflunisal in Domino Liver Transplant Recipients With Acquired Amyloid Neuropathy.

Objectives: To analyze the efficacy and tolerability of diflunisal for the treatment of acquired amyloid neuropathy in domino liver transplant recipients. Methods: We performed a retrospective longitudinal study of prospectively collected data for all domino liver transplant recipients with acquired amyloid neuropathy who received diflunisal at our hospital. Neurological deterioration was defined as an score increase of ≥2 points from baseline on the Neurological Impairment Scale/Neurological Impairment Scale-Lower Limbs. Results: Twelve patients who had received compassionate use treatment with diflunisal were identified, of whom seven had follow-up data for ≥12 months. Five patients (71.4%) presented with neurological deterioration on the Neurological Impairment Scale after 12 months (p = 0.0382). The main adverse effects were cardiovascular and renal, leading to diflunisal being stopped in five patients and the dose being reduced in two patients. Conclusion: Our study suggests that most domino liver transplant recipients with acquired amyloid neuropathy will develop neurological deterioration by 12 months of treatment with diflunisal. This therapy was also associated with a high incidence of adverse effects and low treatment retention. The low efficacy and low tolerability of diflunisal treatment encourage the search for new therapeutic options.

A composite adsorbent of graphene quantum dots, mesoporous carbon, and molecularly imprinted polymer to extract nonsteroidal anti-inflammatory drugs in milk.

A composite magnetic adsorbent was developed by embedding graphene quantum dots (GQDs), silica-modified magnetite (Fe3O4-SiO2), and mesoporous carbon (MPC) into a molecularly imprinted polymer (GQDs/Fe3O4-SiO2/MPC/MIP). The adsorbent was applied to extract nonsteroidal anti-inflammatory drugs (NSAIDs) in milk. The MIP was formed via a sol-gel copolymerization using flurbiprofen, diflunisal, and mefenamic acid as template molecules, 3-aminopropyltriethoxysilane as a monomer, and tetraethyl orthosilicate as a cross-linker. GQDs and MPC enhanced affinity binding between NSAIDs and the adsorbent through π-π stacking, hydrogen bonding, and hydrophobic interaction. The Fe3O4-SiO2 nanoparticles embedded in the composite adsorbent enabled its rapid isolation from the sample solution. The extracted NSAIDs were quantified by high-performance liquid chromatography and exhibited good linearity from 1.0 to 100.0 µg L-1 for flurbiprofen and 0.5 to 100.0 µg L-1 for diflunisal and mefenamic acid, respectively. The limits of detection ranged from 0.5 to 1.0 µg L-1. Recoveries of NSAIDs from spiked milk samples ranged from 81.4 to 93.7%, with RSDs below 7%. The reproducibility of the fabricated adsorbent was good and in the optimal conditions, the developed adsorbent could be used for up to six extraction-desorption cycles.

Role of Microstructure in Drug Release from Chitosan Amorphous Solid Dispersions.

The unexpected dissolution behaviour of amorphous diflunisal-chitosan solid dispersions (kneading method) with respect to the crystalline co-evaporated systems is the starting point of this research. This work is an in-depth study of the diflunisal release behaviour from either chitosan or carboxymethylchitosan dispersions. The microstructure is not usually considered when designing this type of products; however, it is essential to understand the process of solvent penetration and subsequent drug release through a polymeric system, as has been evidenced in this study. In accordance with the kinetic data analysed, it is possible to conclude that the porous structure, conditioned by the sample preparation method, can be considered the main factor involved in diflunisal release. The low mean pore size (1-2 µm), low porosity, and high tortuosity of the amorphous kneaded products are responsible for the slow drug release in comparison with the crystalline coevaporated systems, which exhibit larger pore size (8-10 µm) and lower tortuosity. Nevertheless, all diflunisal-carboxymethylchitosan products show similar porous microstructure and overlapping dissolution profiles. The drug release mechanisms obtained can also be related to the porous structure. Fickian diffusion was the main mechanism involved in drug release from chitosan, whereas an important contribution of erosion was detected for carboxymethylchitosan systems, probably due to its high solubility.

Diflunisal targets the HMGB1/CXCL12 heterocomplex and blocks immune cell recruitment.

Extracellular HMGB1 triggers inflammation following infection or injury and supports tumorigenesis in inflammation-related malignancies. HMGB1 has several redox states: reduced HMGB1 recruits inflammatory cells to injured tissues forming a heterocomplex with CXCL12 and signaling via its receptor CXCR4; disulfide-containing HMGB1 binds to TLR4 and promotes inflammatory responses. Here we show that diflunisal, an aspirin-like nonsteroidal anti-inflammatory drug (NSAID) that has been in clinical use for decades, specifically inhibits in vitro and in vivo the chemotactic activity of HMGB1 at nanomolar concentrations, at least in part by binding directly to both HMGB1 and CXCL12 and disrupting their heterocomplex. Importantly, diflunisal does not inhibit TLR4-dependent responses. Our findings clarify the mode of action of diflunisal and open the way to the rational design of functionally specific anti-inflammatory drugs.

A novel quality by design approach for development and validation of a green reversed-phase HPLC method with fluorescence detection for the simultaneous determination of lesinurad, febuxostat, and diflunisal: Application to human plasma.

A novel and eco-friendly reversed-phase HPLC method with fluorescence detection was developed for simultaneous estimation of two co-administered antigout drugs (lesinurad and febuxostat) with diflunisal as a nonsteroidal anti-inflammatory drug. Unlike routine methodology, the developed method was optimized using analytical quality by design approach. A full factorial design was applied to optimize the effect of variable factors on chromatographic responses. The chromatographic separation was performed using isocratic elution on the Hypersil BDS C18 column at 40°C. The mobile phase consisted of acetonitrile:potassium phosphate buffer (30.0 mM; pH 5.5, 32.2:67.8% v/v) pumped at a flow rate of 1.0 mL/min and injection volume of 20.0 µL was employed. The proposed method was able to separate the ternary mixture in <10 min. The calibration curves of diflunisal, lesinurad, and febuxostat were linear over concentration ranges of 50.0-500.0, 50.0-700.0, and 20.0-700.0 ng/mL, respectively. Recovery percentages ranging from 98.1 to 101.3% with % relative standard deviation of <2% were obtained upon spiking to human plasma samples, indicating high bioanalytical applicability. Furthermore, the method was found to be excellent green when it was assessed according to Green Analytical Procedure Index and analytical Eco-Scale guidelines.

The Ultrastructure of Tissue Damage by Amyloid Fibrils.

Amyloidosis is a group of diseases that includes Alzheimer's disease, prion diseases, transthyretin (ATTR) amyloidosis, and immunoglobulin light chain (AL) amyloidosis. The mechanism of organ dysfunction resulting from amyloidosis has been a topic of debate. This review focuses on the ultrastructure of tissue damage resulting from amyloid deposition and therapeutic insights based on the pathophysiology of amyloidosis. Studies of nerve biopsy or cardiac autopsy specimens from patients with ATTR and AL amyloidoses show atrophy of cells near amyloid fibril aggregates. In addition to the stress or toxicity attributable to amyloid fibrils themselves, the toxicity of non-fibrillar states of amyloidogenic proteins, particularly oligomers, may also participate in the mechanisms of tissue damage. The obscuration of the basement and cytoplasmic membranes of cells near amyloid fibrils attributable to an affinity of components constituting these membranes to those of amyloid fibrils may also play an important role in tissue damage. Possible major therapeutic strategies based on pathophysiology of amyloidosis consist of the following: (1) reducing or preventing the production of causative proteins; (2) preventing the causative proteins from participating in the process of amyloid fibril formation; and/or (3) eliminating already-deposited amyloid fibrils. As the development of novel disease-modifying therapies such as short interfering RNA, antisense oligonucleotide, and monoclonal antibodies is remarkable, early diagnosis and appropriate selection of treatment is becoming more and more important for patients with amyloidosis.

Concurrent Local Delivery of Diflunisal Limits Bone Destruction but Fails To Improve Systemic Vancomycin Efficacy during Staphylococcus aureus Osteomyelitis.

Staphylococcus aureus osteomyelitis is a debilitating infection of bone. Treatment of osteomyelitis is impaired by the propensity of invading bacteria to induce pathological bone remodeling that may limit antibiotic penetration to the infectious focus. The nonsteroidal anti-inflammatory drug diflunisal was previously identified as an osteoprotective adjunctive therapy for osteomyelitis, based on the ability of this compound to inhibit S. aureus quorum sensing and subsequent quorum-dependent toxin production. When delivered locally during experimental osteomyelitis, diflunisal significantly limits bone destruction without affecting bacterial burdens. However, because diflunisal's "quorum-quenching" activity could theoretically increase antibiotic recalcitrance, it is critically important to evaluate this adjunctive therapy in the context of standard-of-care antibiotics. The objective of this study is to evaluate the efficacy of vancomycin to treat osteomyelitis during local diflunisal treatment. We first determined that systemic vancomycin effectively reduces bacterial burdens in a murine model of osteomyelitis and identified a dosing regimen that decreases bacterial burdens without eradicating infection. Using this dosing scheme, we found that vancomycin activity is unaffected by the presence of diflunisal in vitro and in vivo Similarly, locally delivered diflunisal still potently inhibits osteoblast cytotoxicity in vitro and bone destruction in vivo in the presence of subtherapeutic vancomycin. However, we also found that the resorbable polyester urethane (PUR) foams used to deliver diflunisal serve as a nidus for infection. Taken together, these data demonstrate that diflunisal does not significantly impact standard-of-care antibiotic therapy for S. aureus osteomyelitis, but they also highlight potential pitfalls encountered with local drug delivery.

Stabilization of Cardiac Function With Diflunisal in Transthyretin (ATTR) Cardiac Amyloidosis.

BACKGROUND: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an underappreciated cause of heart failure that results from misfolded TTR (prealbumin) protein. Diflunisal is an approved non-steroidal anti-inflammatory drug that stabilizes TTR, with limited data available regarding effects on cardiac structure and function. METHODS AND RESULTS: ATTR-CM patients (n=81, 41% treated with 250 mg twice-daily diflunisal by clinical practice) were retrospectively identified with baseline and follow-up (median interval 1 year) serum biomarker and echocardiographic data compared, including global longitudinal strain (GLS). Chi-squared and Wilcoxon tests assessed differences between subjects, divided by treatment group, and univariable and multivariable linear regression was performed. At baseline, patients treated with diflunisal were younger (68 vs 77 years, P = .0001), with lower B-type natriuretic peptide (BNP; 249 vs 545 pg/mL, P = .009) and serum creatinine (1.1 vs 1.2 mg/dL, P = .04), but similar TTR concentration (P = .31), cardiac troponin I (P = .06), and GLS (P = .67). At follow-up, diflunisal untreated versus treated patients showed differences in TTR concentration (19 vs 33 mg/dL, P = .01) and favorable differences in left atrial volume index (+4.6 vs -1.4 mL/m2, P = .002) and cardiac troponin I (+0.03 vs -0.01 ng/mL, P = .01) for the entire cohort. Among the subset with wild-type ATTR (n=53), diflunisal treatment was associated with differences in GLS (+1.2% untreated vs +0.1% treated, P = .03). Changes in wall thickness (P = .2), left ventricular ejection fraction (P = .71), and BNP (P = .42) were similar between groups. CONCLUSIONS: In ATTR-CM, diflunisal treatment resulted in measurable differences in some parameters of cardiac structure and function after only 1 year of administration. Further longer-term analysis is warranted.

Synthesis, Molecular Docking and Anticancer Activity of Diflunisal Derivatives as Cyclooxygenase Enzyme Inhibitors.

Cyclooxygenase enzymes play a vital role in inflammatory pathways in the human body. Apart from their relation with inflammation, the additional involvement of COX-2 enzyme with cancer activity was recently discovered. In some cancer types the level of COX-2 enzyme is increased indicating that this enzyme could be a suitable target for cancer therapy. Based on these findings, we have synthesized some new diflunisal thiosemicarbazides and 1,2,4-triazoles and tested them against androgen-independent prostate adenocarcinoma (PC-3), colon carcinoma (HCT-116), human breast cancer (T47D), breast carcinoma (MCF7) and human embryonic kidney (HEK-293) cell lines. Specifically, the diflunisal and thiosemicarbazide functionality are combined during the synthesis of original compounds anticipating a potency enhancement. Compounds 6, 10, 15 and 16 did not show cytotoxic effects for the HEK293 cell line. Among them, compounds 15 and 16 demonstrated anticancer activity for the breast cancer cell line T47D, whereas compounds 6 and 10 which are thiosemicarbazide derivatives displayed anti-tumourigenic activity against the PC-3 cell line, consistent with the literature. However, no activity was observed for the HCT-116 cancer cell line with the tested thiosemicarbazide derivatives. Only compound 16 displayed activity against the HCT-116 cell line. Therefore, it was speculated that the diflunisal and thiosemicarbazide functionalities potentiate anticancer activity on prostate cancer and the thiosemicarbazide functionality decreases the anticancer activity of diflunisal on colon cancer cell lines. In order to gain insight into the anticancer activity and COX-2 inhibition, molecular docking studies were carried out for COX-1 and COX-2 enzymes utilizing the newly synthesized compounds 15, and 16. Both 15 and 16 showed high selectivity and affinity toward COX-2 isozyme over COX-1, which is in agreement with the experimental results.

Characterization of a Francisella tularensis-Caenorhabditis elegans Pathosystem for the Evaluation of Therapeutic Compounds.

Francisella tularensis is a highly infectious Gram-negative intracellular pathogen that causes tularemia. Because of its potential as a bioterrorism agent, there is a need for new therapeutic agents. We therefore developed a whole-animal Caenorhabditis elegans-F. tularensis pathosystem for high-throughput screening to identify and characterize potential therapeutic compounds. We found that the C. elegans p38 mitogen-activate protein (MAP) kinase cascade is involved in the immune response to F. tularensis, and we developed a robust F. tularensis-mediated C. elegans killing assay with a Z' factor consistently of >0.5, which was then utilized to screen a library of FDA-approved compounds that included 1,760 small molecules. In addition to clinically used antibiotics, five FDA-approved drugs were also identified as potential hits, including the anti-inflammatory drug diflunisal that showed anti-F. tularensis activity in vitro Moreover, the nonsteroidal anti-inflammatory drug (NSAID) diflunisal, at 4× MIC, blocked the replication of an F. tularensis live vaccine strain (LVS) in primary human macrophages and nonphagocytic cells. Diflunisal was nontoxic to human erythrocytes and HepG2 human liver cells at concentrations of ≥32 µg/ml. Finally, diflunisal exhibited synergetic activity with the antibiotic ciprofloxacin in both a checkerboard assay and a macrophage infection assay. In conclusion, the liquid C. elegans-F. tularensis LVS assay described here allows screening for anti-F. tularensis compounds and suggests that diflunisal could potentially be repurposed for the management of tularemia.

Formulation, characterisation and in vivo evaluation of lipid-based nanocarrier for topical delivery of diflunisal.

Diflunisal (DIF) is non-steroidal anti-inflammatory drug used in the treatment of rheumatoid arthritis, osteoarthritis. The current engrossment was aimed at formulation and assessment of DIF-loaded solid lipid nanoparticles (SLNs) for topical/dermal application. SLNs formulated by hot homogenisation method based on microemulsification technique were spherical with a mean size of 124.0 ± 2.07 nm; PDI 0.294 ± 0.15. The cumulative amount permeated/area was 109.99 ± 0.008 µg/cm(2), along with permeation flux (6.30 ± 0.09 µg/cm(2)/h) and skin retention (11.74 ± 0.155 µg/cm(2)) across mice skin. The SLNs of DIF showed significant decrease in fluid volume, granuloma tissue weight, leukocyte count/mm(3) after application of SLN formulation in mice air pouch model. Similarly, in mice ear oedema and rat paw oedema model, there was 2.30 and 1.29 time increase in percentage inhibition of oedema after SLN formulation application, respectively, as compared with conventional cream. Hence, the SLNs of DIF may prove to be a potential nanocarrier to effectively treat the local inflammatory conditions associated with arthritis.

An insight on human skin penetration of diflunisal: lipogel versus hydrogel microemulsion.

Diflunisal is a NSAID used in acute and long term management of pain and inflammation associated with osteoarthritis, rheumatoid arthritis and symptoms of primary dysmenorrhea. However, its oral use is associated with side effects such as peptic ulceration, dyspepsia, gastrointestinal disturbances and bleeding. The aim of this work was to develop lecithin organogels (LO) transdermal delivery system for diflunisal and to study its human skin penetration ability in comparison with an optimized microemulsion-based hydrogel. Ternary phase diagrams were constructed using butyl lactate as an organic solvent and two commercial grades of lecithin. The formation of gel phase was lecithin concentration dependent with Phosholipion 85 G being capable of forming organogels at lower lecithin concentration than Lipoid S75. The gels prepared using butyl lactate were able to tolerate higher amounts of water than could be incorporated in the lipogels prepared with other organic solvents. All the investigated gels possessed acceptable physical properties and were able to deliver diflunisal through human skin. The lipogels delivered higher total drug amount through the skin than the hydrogel. The composition of lecithin seemed to have some effect on the skin permeability enhancement ability of the lipogel. Lecithin containing higher amount of phosphatidyl ethanolamine could provide better transdermal delivery. The elaborated lecithin organogels are potential carriers that create a good opportunity for transdermal delivery of diflunisal overcoming the side effects associating its oral route.

Pharmaceutical cocrystals of diflunisal and diclofenac with theophylline.

Pharmaceutical cocrystals of nonsteroidal anti-inflammatory drugs diflunisal (DIF) and diclofenac (DIC) with theophylline (THP) were obtained, and their crystal structures were determined. In both of the crystal structures, molecules form a hydrogen bonded supramolecular unit consisting of a centrosymmetric dimer of THP and two molecules of active pharmaceutical ingredient (API). Crystal lattice energy calculations showed that the packing energy gain of the [DIC + THP] cocrystal is derived mainly from the dispersion energy, which dominates the structures of the cocrystals. The enthalpies of cocrystal formation were estimated by solution calorimetry, and their thermal stability was studied by differential scanning calorimetry. The cocrystals showed an enhancement of apparent solubility compared to the corresponding pure APIs, while the intrinsic dissolution rates are comparable. Both cocrystals demonstrated physical stability upon storing at different relative humidity.

Recent progress in the understanding and treatment of transthyretin amyloidosis.

WHAT IS KNOWN AND OBJECTIVE: Transthyretin (TTR) is a representative amyloidogenic protein in humans. Rate-limiting tetramer dissociation and rapid monomer misfolding and misassembly of variant TTR result in autosomal dominant familial amyloidosis. Analogous misfolding of wild-type TTR results in senile systemic amyloidosis (SSA) presenting as sporadic amyloid disease in the elderly. The objective of this review is to summarize recent progress in our understanding and treatment of TTR amyloidosis. METHODS: Literature searches were conducted on the topics of transthyretin, familial amyloid polyneuropathy and clinical trials, using PubMed, the United States clinical trials directory, pharmaceutical company websites and news reports. The information was collected, evaluated for relevance and quality, critically assessed and summarized. RESULTS AND DISCUSSION: The current standard first-line treatment of familial TTR amyloidosis is liver transplantation. However, large numbers of patients are not suitable transplant candidates. Recently, the clinical effects of TTR tetramer stabilizers, tafamidis and diflunisal, were demonstrated in randomized clinical trials, and tafamidis has been approved for the treatment of FAP in European countries and Japan. In addition, gene therapies with antisense oligonucleotides and small interfering RNAs are promising strategies to ameliorate TTR amyloidoses and are currently in clinical trials. WHAT IS NEW AND CONCLUSIONS: Liver transplantation to treat the familial TTR amyloidosis will likely be replaced by other less invasive therapies, such as TTR tetramer stabilizers and possibly gene therapy approaches. These newly developed therapies are expected to be effective for not only familial TTR amyloidosis but also SSA, based on their mechanisms of action.

Effect of Diflunisal in Patients with Transthyretin Cardiomyopathy: A Pilot Study.

Background: ATTR-CM is becoming more prevalent, and disease-modifying therapy has been investigated in recent years with promising results. Diflunisal has shown TTR-stabilizing properties assessed by biomarkers and echocardiography, but there are no trials addressing the evolution of morphological changes with CMR. Methods and Results: AMILCA-DIFLU is an exploratory pilot study prospective, single-center, non-randomized, open-label clinical trial. Patients diagnosed with ATTR-CM underwent clinical, functional, biochemical and imaging assessment before and one year after diflunisal therapy initiation. Of the twelve ATTR-CM patients included, only nine patients completed treatment and study protocol in 12 months. To increase the sample size, we included seven real-world patients with one year of diflunisal treatment. Among the group of patients who completed treatment, diflunisal therapy did not show improvement in cardiac disease status as assessed by many cardiac and inflammatory biomarkers, 6MWT and CMR parameters after one year of treatment. However, a non-significant trend towards stabilization of CMR parameters such as LVEF, ECV and T2 at one year was found. When comparing the group of patients who completed diflunisal therapy and those who did not, a significant decrease in the distance performed in the 6MWT was found in the group of patients who completed treatment at one year (-14 ± 81.8 vs. -173 ± 122.2; p = 0.032). Diflunisal was overall well tolerated, showing only a statistically significant worsening in renal function in the group of diflunisal-treatment patients with no clinical relevance or need for treatment discontinuation. Conclusions: In patients with ATTR-CM, treatment with diflunisal was overall well tolerated and tended to stabilize or slow down amyloid cardiac disease progression assessed by CMR parameters, cardiac and inflammatory biomarkers and functional capacity.

Treatment characteristics of patients with hereditary transthyretin amyloidosis: a cohort study.

BACKGROUND: There are novel medications approved for the treatment of hereditary transthyretin amyloidosis (ATTRv), classified as transthyretin (TTR) stabilizers or gene silencers. While many patients may be on both classes of medications, there is no data available on the safety and efficacy of combination therapy. OBJECTIVES: To describe ATTRv patient and TTR-targeted therapy characteristics in a US cohort, and compare outcomes with combination therapy versus monotherapy. METHODS: We performed a retrospective cohort study with electronic health record data of patients with ATTRv seen at a single institution between January 2018 and December 2022. We collected data on symptomatology, gene mutation, disease severity, ATTRv treatment, hospitalizations, and mortality. RESULTS: One hundred sixty-two patients with ATTRv were identified. The average age at diagnosis was 65 years. 86 patients (53%) had the V122I variant. 119 patients were symptomatic, of whom 103 were started on ATTRv-specific treatment. 41 patients (40%) had cardiomyopathy only, and 53 (51%) had a mixed phenotype of cardiomyopathy and neuropathy. 38 patients (37%) received therapy with both a gene silencer and protein stabilizer. 9 patients (15%) in the monotherapy group had two or more cardiac hospitalizations after starting treatment, compared to 3 patients (9%) on combination therapy (p=0.26). The adjusted hazard ratio of all-cause mortality for the patients on combination therapy compared to monotherapy was 0.37 (0.08-1.8, p=0.21). CONCLUSIONS: While the efficacy is unproven, over one-third of patients with ATTRv are on both a stabilizer and a silencer. There were no safety issues for combination therapy. There was a trend towards improved hospitalizations and survival in patients in the combination group but this was not statistically significant. Larger studies with longer follow-up are necessary to determine benefit of combination therapy.