Pharmacokinetics and Pharmacodynamics of Patisiran in Patients with hATTR Amyloidosis and with Polyneuropathy After Liver Transplantation

BACKGROUND AND OBJECTIVE

Variants of the transthyretin (TTR) gene cause hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis (v for variant), which results from deposition of misfolded TTR protein as amyloid in organs and tissues. Patisiran is an RNA interference (RNAi) therapeutic that suppresses the hepatic production of TTR protein. Patisiran improves multiple clinical manifestations of hATTR amyloidosis in patients without liver transplantation (LT). Because the liver is the predominant source of circulating TTR, LT has been prescribed to eliminate the production of the variant TTR. However, the continued production of wild-type TTR can contribute to disease progression after LT. Patisiran could potentially address an unmet need in these affected patients. This clinical trial was conducted to evaluate the safety, efficacy, and pharmacokinetics (PK) and pharmacodynamics (PD) of patisiran in patients with hATTR amyloidosis with polyneuropathy progression after LT. In this paper, we describe the PK/PD of patisiran in post-LT patients and compare it with prior patisiran studies in healthy subjects and patients without LT.

METHODS

In an open-label study, patients (N = 23) with hATTR amyloidosis with polyneuropathy progression after LT received 0.3 mg/kg patisiran intravenously every 3 weeks (q3w) for 12 months. As a post hoc analysis, the PK and PD results from the current study were compared with prior patisiran studies in healthy volunteers from a Phase 1 study and in patients with hATTR amyloidosis without LT from Phase 2 and 3 studies.

RESULTS

The PK profile of patisiran siRNA (ALN-18328) and its 2 lipid excipients, DLin-MC3-DMA and PEG2000-C-DMG, in hATTR amyloidosis patients after LT was consistent with prior patisiran studies in non-LT subjects. Plasma PK profiles of ALN-18328 and DLin-MC3-DMA exhibited 2 phases, the first characterized by a short distribution half-life and the second by a minor peak and relatively long elimination half-life. The plasma concentrations of PEG2000-C-DMG reached Cmax at the end of infusion and declined in a multiphasic manner. There was no appreciable accumulation at steady state. Consistent with prior studies in non-LT subjects, the post-LT patients showed a robust, and sustained TTR reduction; with median TTR reduction from baseline of 91% (average of Month 6 and Month 12). No anti-drug antibodies were observed in any patient.

CONCLUSIONS

The consistency of patisiran PK and PD between patients with and without LT suggests that neither LT nor concomitantly administered immunosuppressants influence hepatic uptake or RNAi activity of patisiran. The patisiran dosing regimen of 0.3 mg/kg q3w is appropriate for hATTR amyloidosis patients with or without LT.

CLINICAL TRIAL REGISTRATION NO

NCT03862807.

77 HELIOS-A: 18-MONTH EXPLORATORY CARDIAC RESULTS FROM THE PHASE 3 STUDY OF VUTRISIRAN IN PATIENTS WITH HEREDITARY TRANSTHYRETIN-MEDIATED AMYLOIDOSIS

Background

Hereditary transthyretin-mediated (hATTR) amyloidosis, also known as ATTRv amyloidosis, is a fatal, multisystem disease that presents with progressive polyneuropathy and/or cardiomyopathy. HELIOS-A (NCT03759379) assessed the efficacy of vutrisiran, an investigational RNA interference therapeutic, in patients with hATTR amyloidosis with polyneuropathy.

Purpose

To evaluate the effect of 18 months of vutrisiran treatment on exploratory cardiac endpoints in the HELIOS-A Phase 3 study.

Methods

Patients were randomised (3:1) to vutrisiran (25 mg SC, q3m) or patisiran (0.3 mg/kg IV, q3w), a reference comparator. The APOLLO placebo group (n=77) was an external control. Primary endpoint was change from baseline in the modified Neuropathy Impairment Score +7 (mNIS+7) at 9 months, vs. external placebo. Exploratory cardiac endpoints included change from baseline in NT-proBNP levels, echocardiography parameters, and technetium (Tc) scintigraphy parameters at 18 months. A prespecified cardiac subpopulation was included (baseline left ventricular wall thickness ≥1.3 cm and no medical history of aortic valve disease or hypertension).

Results

HELIOS-A enrolled 164 patients and the primary endpoint was met. In the cardiac subpopulation (n=40/122 vutrisiran; n=36/77 placebo), 18 months of vutrisiran treatment significantly improved NT-ProBNP levels vs. external placebo (adjusted geometric fold change ratio: 0.49; p=0.0004) and demonstrated a trend towards improvement in echocardiographic parameters vs. external placebo (including a significant difference in cardiac output [least squares mean difference: 0.41; p=0.043]). Of the 122 vutrisiran-treated patients, 99mTc scintigraphy assessment was captured for 64 vutrisiran-treated patients at baseline, 35 (54.7%) of whom had Perugini grade ≥2 (moderate/intense) cardiac uptake of 99mTc. Among patients with evaluable scintigraphy parameters repeated at 18 months (evaluable patients), heart-to-contralateral lung ratio and normalised LV total uptake on scintigraphy improved (decrease from baseline) in 64.6% (31/48) and 68.1% (32/47), respectively, at 18 months. Of the evaluable patients, 28.1% (16/57) had an improvement (reduction from baseline) in Perugini grade of cardiac uptake, 68.4% (39/57) had no change in grade, and 3.5% (2/57) worsened in grade. Of evaluable patients with baseline Perugini grade ≥2, the proportion with improvement in heart-to-contralateral lung ratio and normalised LV total uptake was 76.9% (20/26) and 100% (25/25) respectively. No cardiac safety concerns were identified with vutrisiran treatment.

Conclusions

In this exploratory analysis, vutrisiran treatment was associated with a positive impact on NT-ProBNP levels and echocardiographic parameters vs. external placebo in the cardiac subpopulation. Vutrisiran treatment also reduced cardiac uptake of 99mTc potentially suggesting reduction in cardiac amyloid, although the clinical significance of this is not yet clear.

Effect of RNAi therapeutics patisiran and vutrisiran on orthostatic hypotension due to dysautonomia in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy

Background

Hereditary transthyretin-mediated (hATTR) amyloidosis, also known as ATTRv amyloidosis, is a rapidly progressive, multisystem disease. Orthostatic hypotension, due to autonomic neuropathy, is a common yet hard-to-treat disease manifestation in patients with hATTR amyloidosis. Fatigue, muscle weakness, and deterioration in cardiac function further exacerbate orthostatic symptoms. Efficacy of RNAi therapeutics patisiran and vutrisiran was assessed in patients with hATTR amyloidosis with polyneuropathy across the APOLLO (NCT01960348), Global Open-Label Extension (OLE) (NCT02510261), and HELIOS-A (NCT03759379) studies, respectively.

Purpose

Evaluate the quantitative effect of patisiran and vutrisiran on orthostatic hypotension in patients with hATTR amyloidosis with polyneuropathy.

Methods

In APOLLO, patients were randomised 2:1 to patisiran 0.3 mg/kg or placebo, IV q3w. Patients who completed APOLLO (APOLLO-placebo, APOLLO-patisiran) were eligible to enrol into the ongoing Global OLE (patisiran 0.3 mg/kg IV q3w). In HELIOS-A, patients were randomised 3:1 to vutrisiran (25 mg SC q3m) or patisiran (0.3 mg/kg IV q3w; reference group). Primary endpoint for APOLLO and HELIOS-A was change from baseline in the modified Neuropathy Impairment Score+7 (mNIS+7) vs APOLLO placebo at M18 (APOLLO) and M9 (HELIOS-A). Orthostatic hypotension was evaluated using the postural blood pressure (PBP) component of mNIS+7, calculated as the mean of 2 supine readings of systolic BP [SBP, mmHg] taken 15 min apart minus the lowest SBP upon standing at 1, 3, and 5 min. A smaller reduction in observed SBP between supine and upright readings indicated an improved PBP.

Results

APOLLO enrolled 225 patients (placebo, n=77; patisiran, n=148), Global OLE 211 and HELIOS-A 164 (vutrisiran, n=122; patisiran, n=42). At baseline, the severity of orthostatic hypotension was similar between within-study treatment arms in APOLLO and HELIOS-A. In APOLLO, patisiran-treated patients showed PBP improvement or stabilization from baseline to M18 (mean [SD] change in SBP: baseline, −17.6 [19.4]; M18, −13.5 [16.8]) and was maintained at Global OLE 36m (−13.4 [15.6]). In contrast, placebo-treated patients in APOLLO had an increased change in PBP over 18m (baseline, −17.5 [16.5]; M18, −20.4 [16.9]); their PBP improved after patisiran initiation (Global OLE 36m, −16.6 [18.1]). In HELIOS-A, stabilization in PBP was observed in the vutrisiran arm (baseline, −11.2 [14.0], M18, −11.7 [14.6]). In the smaller patisiran arm, while the change in PBP increased, the value remained in the normal range (baseline, −11.6 [17.2]; M18, −14.2 [15.5]). Patisiran and vutrisiran have acceptable safety profiles.

Conclusions

PBP analyses quantify the benefits of RNAi therapeutics patisiran and vutrisiran on autonomic function in patients with hATTR amyloidosis with polyneuropathy. The increase in change in PBP to a symptomatic range without treatment indicates the importance of early intervention.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Alnylam Pharmaceuticals

Patisiran treatment in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy after liver transplantation

Hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis, is a progressive disease, for which liver transplantation (LT) has been a long-standing treatment. However, disease progression continues post-LT. This Phase 3b, open-label trial evaluated efficacy and safety of patisiran in patients with ATTRv amyloidosis with polyneuropathy progression post-LT. Primary endpoint was median transthyretin (TTR) reduction from baseline. Twenty-three patients received patisiran for 12 months alongside immunosuppression regimens. Patisiran elicited a rapid, sustained TTR reduction (median reduction [Months 6 and 12 average], 91.0%; 95% CI: 86.1%-92.3%); improved neuropathy, quality of life, and autonomic symptoms from baseline to Month 12 (mean change [SEM], Neuropathy Impairment Score, -3.7 [2.7]; Norfolk Quality of Life-Diabetic Neuropathy questionnaire, -6.5 [4.9]; least-squares mean [SEM], Composite Autonomic Symptom Score-31, -5.0 [2.6]); and stabilized disability (Rasch-built Overall Disability Scale) and nutritional status (modified body mass index). Adverse events were mild or moderate; five patients experienced ≥1 serious adverse event. Most patients had normal liver function tests. One patient experienced transplant rejection consistent with inadequate immunosuppression, remained on patisiran, and completed the study. In conclusion, patisiran reduced serum TTR, was well tolerated, and improved or stabilized key disease impairment measures in patients with ATTRv amyloidosis with polyneuropathy progression post-LT (www.clinicaltrials.gov NCT03862807).

Long-term integrated safety of patisiran in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy

Background/Introduction

Hereditary transthyretin-mediated (hATTR) amyloidosis is a progressive, life-threatening disease; the majority of patients develop a mixed phenotype of polyneuropathy and cardiomyopathy. Patisiran halted or reversed polyneuropathy and improved quality of life in the Phase 3 (APOLLO) study. In a prespecified cardiac subpopulation of APOLLO, patisiran also improved cardiac structure and function versus placebo.

Purpose

To describe the long-term comprehensive, integrated safety data from the patisiran clinical development program in patients with hATTR amyloidosis with polyneuropathy.

Methods

Safety data as of October 7, 2019 from the Phase 2 Open-Label Extension (OLE) (NCT01961921), Phase 3 APOLLO (NCT01960348), and ongoing Global OLE (NCT02510261) studies were analysed.

Results

Across the three studies, 224 patients received patisiran for a mean (range) of 43.6 (0.7–71.7) months, with a cumulative 813.9 patient-years of exposure; 105 (46.9%) patients received patisiran for ≥4 years and 35 (15.6%) patients received patisiran for ≥5 years. In this cohort, 149 (66.5%) had medical histories of cardiac disorders per MedDRA System Organ Class (SOC), which may be reflective of a mixed phenotype in some patients. A total of 222 (99.1%) patients experienced at least one adverse event (AE) and 132 (58.9%) patients experienced at least one serious AE. AEs considered to be related to patisiran and occurring in >5% of patients included infusion-related reactions (IRRs) (25.9%) and diarrhoea (6.3%). Cardiac AEs occurring in >5% of patients included atrial fibrillation (10.7%) and cardiac failure (7.6%). Amongst all patients, the exposure-adjusted mortality rate was 4.3 deaths per 100 patient-years.

Conclusions

Patients with hATTR amyloidosis with polyneuropathy in the patisiran clinical development program represent those with the longest treatment with an RNAi therapeutic, including more than 15% of patients receiving patisiran for ≥5 years. Patisiran continues to demonstrate a positive benefit:risk profile in patients with hATTR amyloidosis with polyneuropathy.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Alnylam Pharmaceuticals

Concept of a Radiofrequency Device for Osteopenia/Osteoporosis Screening

Osteoporosis represents a major health problem, resulting in substantial increases in health care costs. There is an unmet need for a cost-effective technique that can measure bone properties without the use of ionizing radiation. The present study reports design, construction, and testing of a safe, and easy to use radiofrequency device to detect osteoporotic bone conditions. The device uses novel on-body antennas contacting the human wrist under an applied, operator-controlled pressure. For the dichotomous diagnostic test, we selected 60 study participants (23-94 years old, 48 female, 12 male) who could be positively differentiated between healthy and osteopenic/osteoporotic states. The band-limited integral of the transmission coefficient averaged for both wrists, multiplied by age, and divided by BMI has been used as an index. For a 100 MHz frequency band centered about 890-920 MHz, the maximum Youden's J index is 81.5%. Both the sensitivity and specificity simultaneously reach 87% given the calibration device threshold tolerance of ±3%. Our approach correlates well with the available DXA measurements and has the potential for screening patients at risk for fragility fractures, given the ease of implementation and low costs associated with both the technique and the equipment. The inclusion of radiofrequency transmission data does add supplementary useful information to the available clinical risk factors.

SUN-603 A Case of Papillary Thyroid Cancer and EXTRAOVARIAN Pelvic Teratoma

INTRODUCTION Teratomas comprise a spectrum of tumors that have striking imaging appearances and are commonly considered when evaluating a mass in the female pelvis. A subgroup of these tumors located in an extragonadal abdominopelvic location, in contrast, are extremely rare. Thyroid tissue in teratoma may demonstrate the same spectrum of pathological features as in the normal thyroid including benign and malignant changes. Herein, we describe a case of papillary thyroid cancer of the thyroid gland with incidentally diagnosed extraovarian pelvic teratoma. CASE 52 y.o. woman with locally-invasive, multifocal, papillary thyroid carcinoma (PTC) s/p radical thyroidectomy and left central neck dissection. She was treated with thyrogen stimulated 100 mCi I-131, and her post-therapy whole body scan showed uptake in thyroid bed and in the right lower quadrant, for which SPECT imaging was acquired to assess this region better. SPECT imaging showed a heterogeneous, solid lesion seemed to be arising from the left adnexa, which correlated with the region of tracer uptake. The lesion contained fat and dystrophic calcifications with differential considerations including ovarian teratoma/struma ovarii. Her thyrogen stimulated thyroglobulin level was 66 ng/ml. She underwent laparoscopic exploration of the pelvis. Interestingly, the pelvic mass was noted to be completely separate from the left ovary. Pathology result showed a dermoid cyst with thyroid tissue. DISCUSSION A dermoid cyst is a cystic teratoma, usually benign, that contains an array of developmentally mature, solid tissues. In most cases, thyroid tissues found in teratomas are ovarian, not extra-ovarian. There are some case reports of thyroid carcinoma arising in a struma ovarii (thyroid tissue in ovarian teratoma) and a few case reports of synchronous carcinoma in the thyroid gland and the struma ovary. For cases with incidentally found teratoma with thyroid tissue, the next step is to proceed with further work up to confirm the diagnosis and to explore the possibility of a malignant lesion in the mass- either primary or metastasis. For our case, suspicion for metastasis was low as thyrogen stimulated thyroglobulin level was not very high to suggest a distant metastasis. Another important clinical question is whether the iodine uptake in the thyroid tissue in the teratoma will interfere the radio-iodine uptake of the micrometastasis and the long-term outcome. CONCLUSION Radioiodine uptake in the pelvic mass raises the question of possible thyroid tissue- teratoma vs. metastasis. Although teratoma with thyroid tissue might be an incidental finding, this might change the long-term outcome of patients with thyroid cancer treated with radioiodine.

The occurrence, diversity and blood feeding patterns of potential vectors of dengue and yellow fever in Kacheliba, West Pokot County, Kenya

INTRODUCTION

Yellow fever (YF) and dengue (DEN) viruses are important re-emerging mosquito-borne viruses sharing similar vectors and reservoirs. The last documented YF outbreak in Kenya occurred in 1992-95. However, YF virus is re-emerging in bordering countries including Uganda, Ethiopia and South Sudan with the potential for spread to the neighboring regions in Kenya. Dengue is endemic in Kenya with outbreaks being detected in various towns in the north and the coast. This study reports on the Aedes (Stegomyia) mosquito species occurrence, diversity, and blood feeding patterns, as means of measuring the risk of transmission of YF and DEN in Kacheliba sub-county, West Pokot County, which borders previous YF outbreak areas in eastern Uganda.

METHODOLOGY

Adult mosquitoes were collected using CO₂-baited BG Sentinel traps at three time points during the rainy season. Mosquitoes were identified to the species level. Species abundance during the three sampling periods were compared, with emphasis on Aedes aegypti and other Stegomyia species, using generalized linear models that included mosquito diversity. Individually blood-fed mosquitoes were analyzed by DNA amplification of the 12S rRNA gene followed by sequencing to determine the source of blood meal.

RESULTS

Overall, 8605 mosquitoes comprising 22 species in 5 genera were collected. Sampled Stegomyia species included Ae. aegypti (77.3%), Ae. vittatus (11.4%), Ae. metallicus (10.2%) and Ae. unilineatus (1.1%). Ae. aegypti dominated the blood-fed specimens (77%, n = 68) and were found to have fed mostly on rock hyraxes (79%), followed by goats (9%), humans and cattle (each 4%), with a minor proportion on hippopotamus and rock monitor lizards (each comprising 1%).

CONCLUSION

Our findings reveal the presence of important Stegomyia species, which are known potential vectors of YF and DEN viruses. In addition, evidence of more host feeding on wild and domestic animals (hyrax and goat) than humans was observed. How the low feeding on humans translates to risk of transmission of these viruses, remains unclear, but calls for further research including vector competence studies of the mosquito populations for these viruses. This forms part of a comprehensive risk assessment package to guide decisions on implementation of affordable and sustainable vaccination (YF) and vector control plans in West Pokot County, Kenya.

Re-evaluating osteoporosis and fracture risk in Crohn's disease patients in the era of TNF-alpha inhibitors

INTRODUCTION

Patients with Crohn's disease (CD) are at increased risk for osteoporosis and fractures as compared to the general population. Recently, various cytokines including tumor necrosis factor (TNF)-alpha are found to play a major role in bone health. In this study, we aimed to gain a better understanding of the risk factors for osteoporosis and vitamin D deficiency in the era of TNF-alpha inhibitors.

METHODS

We conducted a retrospective review of 464 consecutive patients with CD in our GI clinic between 2008 and 2015. Statistical analysis was performed using the student t-test and chi-square test.

RESULTS

CD patients treated with TNF-alpha inhibitors (TNF) and those who are anti-TNF naïve (NB) had similar rates of vitamin D deficiency, insufficiency and normal vitamin D-25-OH levels. Similarly, rates of osteoporosis (16% vs 18%), osteopenia (53% vs 57%) and normal bone density (31% vs 25%) were comparable between the TNF and NB groups respectively. However, Z-scores at the spine (-0.47 vs -0.05) were significantly lower in the TNF group (p = .03). Interestingly, rates of osteoporosis in the NB group were drastically different before and after age 60 (3.6% vs 30%) with no major difference in the TNF group (15% vs 18%). Bone density was positively correlated with BMI (Pearson's R = 0.39) and negatively correlated with age and smoking status (R= -0.25).

CONCLUSIONS

TNF group patients were diagnosed with osteoporosis from an earlier age compared to NB group but with a smaller increase in osteoporosis after menopause. Further prospective studies are necessary to further determine the role of anti-TNF medications in osteoporosis.

Vitamin D Deficiency and Osteoporosis in Rehabilitation Inpatients

OBJECTIVE

To determine vitamin D status and bone mineral density (BMD) in patients admitted to a subacute rehabilitation facility.

DESIGN

Cross-sectional cohort study.

SETTING

Subacute rehabilitation facility.

PARTICIPANTS

Fifty-three community-dwelling patients admitted from June through February 2005.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

BMD, 25-hydroxyvitamin D (25[OH]D), C-telopeptide (CTX), osteocalcin, and dietary milk intake.

RESULTS

Prevalence of vitamin D deficiency (25[OH]D <20 ng/mL) was 49.1%, while a total of 83% of patients were either vitamin D deficient or insufficient (25[OH]D <30 ng/mL). The prevalence of osteopenia (T score, <-1) was 52.8%; osteoporosis (T score, <-2.5) was 17.0%. CTX (bone resorption marker) was elevated in 60.4% of patients. Osteocalcin (bone formation marker) was elevated in 13.2% of patients. Measurements of bone resorption and formation positively correlated (R2 = .22) indicating increased bone remodeling.

CONCLUSIONS

Vitamin D deficiency and osteopenia and osteoporosis were highly prevalent in patients admitted for rehabilitation. Elevated bone resorption and remodeling were evident. This could be due to vitamin D deficiency that should be corrected before antiresorptive therapy is considered. The study emphasizes the need for vigilance for vitamin D status and BMD testing in patients admitted to rehabilitation facilities.

123I thyroid uptake and thyroid size at 24, 48, and 72 hours after the administration of recombinant human thyroid-stimulating hormone to normal volunteers

CONTEXT

Recombinant human TSH (rhTSH) is used to evaluate thyroid carcinoma patients and off-label for (131)I thyroid ablation and nontoxic goiter therapy.

OBJECTIVE

Our objective was to determine the optimal time for (131)I administration after rhTSH.

PARTICIPANTS

Twenty-five euthyroid nongoitrous volunteers participated in the study.

DESIGN

Baseline 24-h thyroid (123)I uptake (RAIU) was measured, and then 0.1 mg rhTSH was administered. (123)I was administered 24, 48, or 72 h after rhTSH, and a repeat 24-h RAIU was obtained.

SETTING

The study was conducted at an academic research center.

MAIN OUTCOME MEASURES

Thyroid function tests, thyroid ultrasounds, and electrocardiograms were measured before rhTSH, then daily for 4 d, and finally 7 d after rhTSH.

RESULTS

Serum TSH concentrations 24 h after rhTSH increased from 1.7 +/- 0.5 muU/ml (mean +/- sd) to 13.3 +/- 4. The 24-h RAIUs rose from 25 +/- 5 to 47 +/- 8% (88% increase) when the (123)I was given at 24 h after rhTSH and from 29.8 +/- 7 to 40.5 +/- 13% (36% increase) when the (123)I was given at 48 h and were unchanged when the (123)I was given at 72 h. The post-rhTSH RAIU increase was greater at 24 than at 72 h (P < 0.005) and marginally greater than at 48 h (P = 0.057). Thyroid volumes significantly increased 48 h after rhTSH (10 +/- 3.8 vs. 11.1 +/- 3.7 ml; P < 0.009). Electrocardiograms were normal.

CONCLUSIONS

Marked increases in RAIU occurred when (123)I was given 24 h after rhTSH administration to euthyroid volunteers. Smaller increases were observed at 48 h and none at 72 h.