Safety and Efficacy of Radiosynoviorthesis: A Prospective Canadian Multicenter Study.

Radiosynoviorthesis is approved in several European countries and the United States to treat refractory synovitis in many inflammatory joint diseases, such as rheumatoid arthritis, spondyloarthropathies, and other arthritic joint diseases. No radiopharmaceuticals for radiosynoviorthesis are currently approved in Canada. The aim of this Health Canada-approved trial was to demonstrate the safety and efficacy of radiosynoviorthesis. Methods: Between July 2012 and November 2017, we conducted a multicenter, prospective, interventional Canadian trial. Patients (n = 360) with synovitis refractory to standard treatments after failing 2 intraarticular glucocorticoid injections were included. They were followed up at 3, 6, and 12 mo. Outcome measures included adverse events (AEs) and clinical signs of synovitis (pain, swelling, and joint effusion) measured with the Health Assessment Questionnaire Disability Index, the Disease Activity Score, and the Visual Analog Scale. Results: In total, 392 joints were treated, including those reinjected after 6 mo (n = 34). Of these, 83.4% (327/392) were injected with [90Y]Y-citrate for the knees and 9.9% (39/392) with [186Re]Re-sulfide for medium-sized joints. Of the joints treated, 82.7% (324/392) were knees. Fifty-five AEs, most of them of mild grade, occurred and resolved without sequelae and were not life-threatening. The incidence of radiosynoviorthesis-related AEs was 9.4% (34/360). The proportion of patients showing an improvement in synovitis symptoms after radiosynoviorthesis was significant at 3 mo and was maintained up to 12 mo (P < 0.001). Conclusion: This study confirmed the safety of radiosynoviorthesis in the treatment of patients with synovitis refractory to standard treatments. There is evidence of sustained clinical efficacy at 12 mo, suggesting that radiosynoviorthesis is an effective treatment for improving synovitis symptoms.

Safety and therapeutic value of radiosynoviorthesis with yttrium-90: a Canadian single-centre experience.

BACKGROUND: Yttrium-90 (90Y) is approved in several countries as a radiosynoviorthesis agent in the intra-articular treatment of synovitis, however, no such radiopharmaceuticals are approved in Canada. The aim of this Health Canada-approved study was to examine the safety and efficacy of 90Y synovectomy among patients with refractory synovitis. METHODS: We performed a subset analysis of a prospective, phase III, single-arm, pan-Canadian trial. Large and medium-sized joints of adults with refractory inflammatory mono- or oligo-arthritis and minimal cartilage/bone destruction who failed treatment with two intra-articular corticosteroid injections were eligible. Patient follow-up was at 3, 6 and 12 months. Outcome measures included joint tenderness, swelling, effusion, joint function and bone scans. RESULTS: A total of 79 joints were included (90% knees). The underlying diagnosis included SpA (35.2% of patients), RA (26.8%), JIA (8.5%) and other (29.6%). Non-biologic DMARDs were concurrently used in 59.2% of patients and biologic/targeted synthetic DMARDs in 31%. Five adverse events occurred, including one serious radiation burn requiring surgery. All events were non-life-threatening and resolved. Significant improvements in joint tenderness, swelling and effusion were achieved at 3 months (P < 0.001), which were maintained until 12 months. During follow-up, 92.3% of joints did not show radiographic progression. Per the treating physician, clinically important improvement in joint function was observed in 90% of joints. CONCLUSION: Our results confirm the safety of 90Y radiosynoviorthesis in refractory synovitis and provide preliminary evidence supporting its clinical efficacy with sustained benefit at 12 months, suggesting that it is a safe alternative to surgical synovectomy in such cases. This is the first such study in a Canadian cohort.

Improved Estrogen Receptor Assessment by PET Using the Novel Radiotracer 18F-4FMFES in Estrogen Receptor-Positive Breast Cancer Patients: An Ongoing Phase II Clinical Trial.

After encouraging preclinical and human dosimetry results for the novel estrogen receptor (ER) PET radiotracer 4-fluoro-11ß-methoxy-16α-18F-fluoroestradiol (18F-4FMFES), a phase II clinical trial was initiated to compare the PET imaging diagnostic potential of 18F-4FMFES with that of 16α-18F-fluoroestradiol (18F-FES) in ER-positive (ER+) breast cancer patients. Methods: Patients diagnosed with ER+ breast cancer (n = 31) were recruited for this study, including 6 who underwent mastectomy or axillary node dissection. For each patient, 18F-FES and 18F-4FMFES PET/CT scans were done sequentially (within a week) and in random order. One hour after injection of either radiotracer, a head-to-thigh static scan with a 2-min acquisition per bed position was obtained. Blood samples were taken at different times after injection to assess each tracer metabolism by reverse-phase thin-layer chromatography. The SUVmean of nonspecific tissues and the SUVmax of the tumor were evaluated for each detected lesion, and tumor-to-nonspecific organ ratios were calculated. Results: Blood metabolite analysis 60 min after injection of the tracer showed a 2.5-fold increase in metabolic stability of 18F-4FMFES over 18F-FES. Although for most foci 18F-4FMFES PET had an SUVmax similar to that of 18F-FES PET, tumor contrast improved substantially in all cases. Lower uptake was consistently observed in nonspecific tissues for 18F-4FMFES, notably a 4-fold decrease in blood-pool activity as compared with 18F-FES. Consequently, image quality was considerably improved using 18F-4FMFES, with lower overall background activity. As a result, 18F-4FMFES successfully identified 9 more lesions than 18F-FES. Conclusion: This phase II study with ER+ breast cancer patients showed that 18F-4FMFES PET achieves a lower nonspecific signal and better tumor contrast than 18F-FES PET, resulting in improved diagnostic confidence and lower false-negative diagnoses.

Clinical Trial with Sodium 99mTc-Pertechnetate Produced by a Medium-Energy Cyclotron: Biodistribution and Safety Assessment in Patients with Abnormal Thyroid Function.

A single-site prospective open-label clinical study with cyclotron-produced sodium 99mTc-pertechnetate (99mTc-NaTcO4) was performed in patients with indications for a thyroid scan to demonstrate the clinical safety and diagnostic efficacy of the drug and to confirm its equivalence with conventional 99mTc-NaTcO4 eluted from a generator. Methods:99mTc-NaTcO4 was produced from enriched 100Mo (99.815%) with a cyclotron (24 MeV; 2 h of irradiation) or supplied by a commercial manufacturer (bulk vial eluted from a generator). Eleven patients received 325 ± 29 (mean ± SD) MBq of the cyclotron-produced 99mTc-NaTcO4, whereas the age- and sex-matched controls received a comparable amount of the generator-derived tracer. Whole-body and thyroid planar images were obtained for each participant. In addition to the standard-energy window (140.5 keV ± 7.5%), data were acquired in lower-energy (117 keV ± 10%) and higher-energy (170 keV ± 10%) windows. Vital signs and hematologic and biochemical parameters were monitored before and after tracer administration. Results: Cyclotron-produced 99mTc-NaTcO4 showed organ and whole-body distributions identical to those of conventional 99mTc-NaTcO4 and was well tolerated. All images led to a clear final diagnosis. The fact that the number of counts in the higher-energy window was significantly higher for cyclotron-produced 99mTc-NaTcO4 did not influence image quality in the standard-energy window. Image definition in the standard-energy window with cyclotron-produced 99mTc was equivalent to that with generator-eluted 99mTc and had no particular features allowing discrimination between the 99mTc production methods. Conclusion: The systemic distribution, clinical safety, and imaging efficacy of cyclotron-produced 99mTc-NaTcO4 in humans provide supporting evidence for the use of this tracer as an equivalent for generator-eluted 99mTc-NaTcO4 in routine clinical practice.

Radioisotopic Purity of Sodium Pertechnetate 99mTc Produced with a Medium-Energy Cyclotron: Implications for Internal Radiation Dose, Image Quality, and Release Specifications.

UNLABELLED: Cyclotron production of 99mTc is a promising route to supply 99mTc radiopharmaceuticals. Higher 99mTc yields can be obtained with medium-energy cyclotrons in comparison to those dedicated to PET isotope production. To take advantage of this capability, evaluation of the radioisotopic purity of 99mTc produced at medium energy (20-24 MeV) and its impact on image quality and dosimetry was required. METHODS: Thick 100Mo (99.03% and 99.815%) targets were irradiated with incident energies of 20, 22, and 24 MeV for 2 or 6 h. The targets were processed to recover an effective thickness corresponding to approximately 5-MeV energy loss, and the resulting sodium pertechnetate 99mTc was assayed for chemical, radiochemical, and radionuclidic purity. Radioisotopic content in final formulation was quantified using γ-ray spectrometry. The internal radiation dose for 99mTc-pertechnetate was calculated on the basis of experimentally measured values and biokinetic data in humans. Planar and SPECT imaging were performed using thin capillary and water-filled Jaszczak phantoms. RESULTS: Extracted sodium pertechnetate 99mTc met all provisional quality standards. The formulated solution for injection had a pH of 5.0-5.5, contained greater than 98% of radioactivity in the form of pertechnetate ion, and was stable for at least 24 h after formulation. Radioisotopic purity of 99mTc produced with 99.03% enriched 100Mo was greater than 99.0% decay corrected to the end of bombardment (EOB). The radioisotopic purity of 99mTc produced with 99.815% enriched 100Mo was 99.98% or greater (decay corrected to the EOB). The estimated dose increase relative to 99mTc without any radionuclidic impurities was below 10% for sodium pertechnetate 99mTc produced from 99.03% 100Mo if injected up to 6 h after the EOB. For 99.815% 100Mo, the increase in effective dose was less than 2% at 6 h after the EOB and less than 4% at 15 h after the EOB when the target was irradiated at an incident energy of 24 MeV. Image spatial resolution and contrast with cyclotron-produced 99mTc were equivalent to those obtained with 99mTc eluted from a conventional generator. CONCLUSION: Clinical-grade sodium pertechnetate 99mTc was produced with a cyclotron at medium energies. Quality control procedures and release specifications were drafted as part of a clinical trial application that received approval from Health Canada. The results of this work are intended to contribute to establishing a regulatory framework for using cyclotron-produced 99mTc in routine clinical practice.

Preventing MEK1 activation influences the responses of human osteosarcoma cells to bone morphogenetic proteins 2 and 9.

It was recently suggested that bone morphogenetic protein (BMP)-2 may be useful for treating osteosarcoma cells. BMP-9, which has been patented to treat breast and prostate cancers, has a higher osteoinductive potential than BMP-2. Peptides derived from the knuckle epitope of BMPs (pBMPs) also induced osteogenic differentiation. However, the effect of BMP-9 and pBMPs on osteosarcoma cells is unclear. We analyzed the effects of BMP-2, BMP-9, pBMP-2, and pBMP-9 on the behavior of human MG-63 and SaOS-2 osteosarcoma cells. An inhibitor of MEK1 activation (PD98059) that prevents downstream extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and a specific inhibitor of p38 were also used as mitogen activated protein kinase-targeting therapy is being investigated as a treatment modality for osteosarcoma. BMP-2 and BMP-9 (1.92 nmol/l) induced the phosphorylation of Smad1/5/8 in both osteosarcoma cells within 1 h but had different effects on mitogen activated protein kinase pathways. Whereas BMP-2 mainly activated ERK1/2, BMP-9 phosphorylated p38 within 1 h. pBMP-2 did not activate either the Smad or ERK/p38, whereas pBMP-9, like BMP-9, induced both Smad1/5/8 and p38 phosphorylation. p38 activation by BMP-9 or pBMP-9 was also enhanced by PD98059. However, BMP-2 or BMP-9 increased the amounts of distal-less homeobox 5 and Osterix mRNAs in SaOS-2 cells within 6 h, whereas pBMP-9 had no effect. PD98059 promoted the highest level of Osterix mRNA in SaOS-2 cells incubated with BMP-2 or BMP-9, whereas p38 inhibitor had no effect. Furthermore, PD98059 induced the lowest proliferation of MG-63 cells incubated with BMP-2, whereas p38 inhibitor did not affect the proliferation of either osteosarcoma cell line. Therefore a combination of BMP-2 or BMP-9 and an inhibitor of MEK1 may be a promising tool for regulating osteosarcoma cell behavior.

Sanguinarine induces apoptosis of human osteosarcoma cells through the extrinsic and intrinsic pathways.

The quaternary benzo[c]phenanthridine alkaloid sanguinarine inhibits the proliferation of cancerous cells from different origins, including lung, breast, pancreatic and colon, but nothing is known of its effects on osteosarcoma, a primary malignant bone tumour. We have found that sanguinarine alters the morphology and reduces the viability of MG-63 and SaOS-2 human osteosarcoma cell lines in concentration- and time-dependent manner. Incubation with 1 micromol/L sanguinarine for 4 and 24h killed more efficiently MG-63 cells than SaOS-2 cells, while incubation with 5 micromol/L sanguinarine killed almost 100% of both cell populations within 24h. This treatment also changed the mitochondrial membrane potential in both MG-63 and SaOS-2 cells within 1h, caused chromatin condensation and the formation of apoptotic bodies. It activated multicaspases, and increased the activities of caspase-8 and caspase-9 in both MG-63 and SaOS-2 cells. These data highlight sanguinarine as a novel potential agent for bone cancer therapy.

Effect of functionalized polycaprolactone on the behaviour of murine preosteoblasts.

The efficiency of biomaterials used in bone repair depends greatly on their ability to interact with bone cells. Hence, we have functionalized polycaprolactone (PCL) films by peptides derived from the bone sialoprotein containing RGD sequence (pRGD), to increase their ability to interact with murine MC3T3-E1 preosteoblasts, and favour cell response to recombinant human bone morphogenetic protein-2 (rhBMP-2). RGE peptides (pRGE) were used as negative controls. The PCL films were hydrolyzed with NaOH and then carboxylic acid groups were activated to allow chemisorption of the peptides. Alkaline treatment increased the hydrophilicity of PCL films without significantly change their roughness. Peptide immobilization on PCL was checked by X-ray photoelectron spectroscopy. Hydrolyzed PCL films (Hydro PCL), which adsorbed fibronectin and vitronectin from serum after 1 h incubation, prevented the spreading of MC3T3-E1 preosteoblasts, while films bearing pRGD or pRGE did not. In contrast, MC3T3-E1 preosteoblasts attached to pRGD and incubated for 1 h in serum-free medium spread better than cells on Hydro PCL or pRGE. Only cells on pRGD had organized cytoskeleton, phosphorylated focal adhesion kinase on Y(397) and responded to rhBMP-2 by activating Smad pathway. Thus, pRGD PCL may be used to favour bone cell cytoskeletal organization and response to rhBMP-2.

Murine preosteoblast differentiation induced by a peptide derived from bone morphogenetic proteins-9.

Bone morphogenetic proteins (BMPs) increase the differentiation of osteoblasts implicated in bone formation and repair. In a previous study, we demonstrated that a peptide derived from BMP-9 (pBMP-9) at 400 ng/mL inhibited murine preosteoblasts MC3T3-E1 proliferation. Here, we compared the effects of equimolar concentrations of BMP-2 (50 ng/mL), BMP-9 (42.3 ng/mL), and pBMP-9 (4.52 ng/mL) on the differentiation of MC3T3-E1 in a serum-free medium. Like BMP-2, BMP-9 and pBMP-9 activated the Smad pathway. In contrary to BMP-2, the Smad phosphorylation induced by BMP-9 and pBMP-9 is not prevented by noggin, an extracellular antagonist of BMP-2. Further, BMP-9 and pBMP-9 increased, dose dependently, alkaline phosphatase activity, an early marker of osteoblast differentiation, after 1 day. Quantitative real-time polymerase chain reaction analysis demonstrated that BMP-2, BMP-9, and pBMP-9 (4.52 or 400 ng/mL) all activated the transcription of Runx2, Osterix, type I collagen alpha1 chain, and Osteocalcin genes within day 6. Alizarin red S quantification demonstrated that pBMP-9 (400 ng/mL) and pBMP-9 (4.52 ng/mL) allowed a slight deposition of Ca(2+) in the extracellular matrix of cells within 12 and 18 days, respectively. Therefore, pBMP-9 might be a promising replacement for costly BMP in tissue engineering applications that require a well-defined serum-free medium.

Bone cells-biomaterials interactions.

With the aging population, the incidence of bone defects due to fractures, tumors and infection will increase. Therefore, bone replacement will become an ever bigger and more costly problem. The current standard for bone replacement is autograft, because these transplants are osteoconductive and osteoinductive. However, harvesting an autograft requires additional surgery at the donor site that is related to high level of morbidity. In addition, the quantity of bone tissue that can be harvested is limited. These limitations have necessitated the pursuit of alternatives using biomaterials. The control of bone tissue cell adhesion to biomaterials is an important requirement for the successful incorporation of implants or the colonization of scaffolds for tissue repair. Controlling cells-biomaterials interactions appears of prime importance to influence subsequent biological processes such as cell proliferation and differentiation. Therefore, interactions of cells with biomaterials have been widely studied especially on two-dimensional systems. This review focuses on these interactions.