Clinical response to benralizumab can be predicted by combining clinical outcomes at 3†months with baseline characteristics.

Background: Benralizumab is highly effective in many, but not all, patients with severe asthma. Baseline characteristics alone are insufficient to predict an individual's probability of long-term benralizumab response. The objectives of the present study were to: 1) study whether parameters at 3 months, in addition to baseline characteristics, contribute to the prediction of benralizumab response at 1 year; and 2) develop an easy-to-use prediction tool to assess an individual's probability of long-term response. Methods: We assessed the effect of benralizumab treatment in 192 patients from the Dutch severe asthma registry (RAPSODI). To investigate predictors of long-term benralizumab response (≥50% reduction in maintenance oral corticosteroid (OCS) dose or annual exacerbation frequency) we used logistic regression, including baseline characteristics and 3-month Asthma Control Questionnaire (ACQ-6) score and maintenance OCS dose. Results: Benralizumab treatment significantly improved several clinical outcomes, and 144 (75%) patients were classified as long-term responders. Response prediction improved significantly when 3-month outcomes were added to a predictive model with baseline characteristics only (area under the receiver-operating characteristic (AUROC) 0.85 versus 0.72, p=0.001). Based on this model, a prediction tool using sex, prior biologic use, baseline blood eosinophils, forced expiratory volume in 1 s, and at 3 months OCS dose and ACQ-6 was developed which classified patients into three categories with increasing probability of long-term response (95% CI): 25% (3-65%), 67% (57-77%) and 97% (91-99%), respectively. Conclusion: In addition to baseline characteristics, treatment outcomes at 3 months contribute to the prediction of benralizumab response at 1 year in patients with severe eosinophilic asthma. Prediction tools as proposed in this study may help physicians optimise the use of costly biologics.

Cumulative corticosteroid-sparing effect of anti-interleukin-5/5Ra in eosinophilic asthma.

BACKGROUND: Anti-interleukin (IL)-5/IL-5 receptor α (IL-5Ra) therapy has been shown to reduce maintenance oral corticosteroid (OCS) dose in severe eosinophilic asthma. However, the effect on cumulative OCS exposure is currently unknown. Neither is it known how prior OCS exposure affects response to anti-IL-5/5Ra treatment. We aimed primarily to compare the cumulative OCS exposure over a 2-year period before and after anti-IL-5/5Ra initiation, and secondarily to investigate whether duration and cumulative OCS exposure prior to anti-IL-5/5Ra influence the ability to discontinue OCS within 2 years of anti-IL-5/5Ra therapy. METHODS: This real-world nationwide observational registry-based study evaluated all dispensed OCS from 389 adults with severe eosinophilic asthma included in the Dutch Severe Asthma Registry (RAPSODI) 2 years before and 2 years after initiating anti-IL-5/5Ra. The Wilcoxon signed-rank test and multivariable regression analyses were used. RESULTS: Median (interquartile range) cumulative OCS exposure in the 2 years before and after anti-IL-5/5Ra initiation decreased from 2.715 (1.150-5.539) to 1.050 (0.300-3.640) g (p<0.001). 52% of patients were able to discontinue OCS within 2 years after anti-IL-5/5Ra therapy, which was independently predicted by lower and shorter prior OCS exposure. CONCLUSIONS: This real-world study showed that anti-IL-5/5Ra therapy leads to a significant reduction in cumulative OCS exposure over a 2-year period. Patients with lower and shorter OCS exposure were more likely to completely eliminate OCS. Since cumulative exposure increased progressively prior to anti-IL-5/5Ra initiation, our data suggest that early intervention leads to a better long-term prognosis in patients with severe eosinophilic asthma.

Long-term toxicity of holmium-loaded poly(L-lactic acid) microspheres in rats.

The aim of this study was to get insight into the toxic effects of holmium-166-loaded poly(L-lactic acid) microspheres (Ho-PLLA-MS) which have very interesting features for treatment of liver malignancies. Acute, mid- and long-term effects were studied in healthy Wistar rats by evaluating clinical, biochemical and tissue response. Rats were divided into four treatment groups: sham, decayed neutron-irradiated Ho-PLLA-MS, non-irradiated Ho-PLLA-MS and PLLA-MS. After implantation of the microspheres into the liver of the rats, the animals were monitored (body weight, temperature and liver enzymes) for a period of 14-18 months. Some of the rats that received previously neutron-irradiated Ho-PLLA-MS were periodically scanned with magnetic resonance imaging (MRI) to see if holmium was released from the microspheres. After sacrifice, the liver tissue was histologically evaluated. Bone tissue was subjected to neutron-activation analysis in order to examine whether accumulation of released holmium in the bone had occurred. No measurable clinical and biochemical toxic effects were observed in any of the treatment groups. Furthermore, histological analyses of liver tissue samples only showed signs of a slight chronic inflammation and no significant differences in the tissue reaction between rats of the different treatment groups could be observed. The non-irradiated PLLA-MS and Ho-PLLA-MS stayed intact during the study. In contrast, 14 months after administration, the neutron-irradiated Ho-PLLA-MS was not completely spherical anymore, indicating that degradation had started. However, the holmium loading had not been released as was illustrated with MRI and affirmed by neutron-activation analysis of bone tissue. In conclusion, neutron-irradiated Ho-PLLA-MS does not provoke any toxic reaction and can be applied safely in vivo.

Lanthanide-loaded liposomes for multimodality imaging and therapy.

UNLABELLED: Many advanced molecular imaging agents are currently being investigated preclinically. Especially, liposomes, have proven to be very promising carrier systems for diagnostic agents for use in single-photon emission computed tomography (SPECT) or magnetic resonance imaging (MRI), as well as for therapeutic agents to treat diseases such as cancer. In this study, nanosized liposomes were designed and labeled with the radionuclides, holmium-166 (both a beta- and gamma-emitter and also highly paramagnetic) or technetium-99m, and coloaded with paramagnetic gadolinium allowing multimodality SPECT and MR imaging and radionuclide therapy with one single agent. METHODS: Diethylenetriaminepentaacetic acid bisoctadecylamide (an amphiphilic molecule with a chelating group suitable for labeling with radionuclides) and gadoliniumacetylacetonate (GdAcAc) (a small lipophilic paramagnetic molecule) were incorporated in liposomes. The liposomes were characterized by measuring their mean size and size distribution, gadolinium content, and radiochemical stability after incubation in human serum at 37 degrees C. The MRI properties (in vitro) were determined by use of relaxivity measurements at 1.5 and 3.0 Tesla in order to evaluate their potency as imaging agents. RESULTS: The liposomes were successfully labeled with holmium-166, resulting in a high labeling efficiency (95% +/- 1%) and radiochemical stability (> 98% after 48 hours of incubation), and coloaded with GdAcAc. Labeling of liposomes with technetium-99m was somewhat less efficient (85% +/- 2%), although their radiochemical stability was sufficient (95% +/- 1% after 6 hours of incubation). MRI measurements showed that the incorporation of GdAcAc had a strong effect on the MRI relaxivity. CONCLUSIONS: The synthesized liposomes allow for multimodality imaging and therapy, which makes these new agents highly attractive for future applications.

Holmium-loaded poly(L-lactic acid) microspheres: in vitro degradation study.

The clinical application of holmium-loaded poly(L-lactic acid) (PLLA) microspheres for the radionuclide treatment of liver malignancies requires in depth understanding of the degradation characteristics of the microspheres. To this end, an in-vitro degradation study was conducted. PLLA-microspheres with and without HoAcAc loading, and before and after neutron or gamma irradiation, were incubated in a phosphate buffer at 37 degrees C for 12 months. In contrast with the other microsphere formulations, only the neutron-irradiated Ho-PLLA-MS disintegrated. At the end of the experiment (52 weeks) highly crystalline fragments, as evidenced from Differential Scanning Calorimetry, were present. Infrared spectroscopy showed that these fragments consisted of holmium lactate. In conclusion, this study demonstrates that the degradation of neutron-irradiated Ho-PLLA-MS was substantially accelerated by the HoAcAc incorporation and subsequent neutron irradiation. The degradation of these microspheres in aqueous solution resulted in the formation of insoluble holmium lactate microcrystals without release of Ho3+.

Internal radiation therapy of liver tumors: qualitative and quantitative magnetic resonance imaging of the biodistribution of holmium-loaded microspheres in animal models.

In internal radiation therapy of unresectable liver tumors, microspheres containing a radionuclide are injected in the hepatic artery to achieve a preferential deposition of microspheres in the lesions. In this study, MR imaging techniques for qualitative and quantitative assessment of the biodistribution of holmium-loaded microspheres (HoMS) were investigated for their use in selective internal radiation therapy of liver tumors. To achieve this goal, the relaxivity of HoMS was first investigated in gel experiments. The resultant calibration curve was subsequently employed to quantify the biodistribution of HoMS administered to 13 excised rabbit livers and to the livers of 3 live rabbits with an implanted tumor. Finally, the feasibility of MR imaging of the biodistribution during treatment of a large animal was investigated by MR imaging of hepatic administration of HoMS to a live pig. Overall, the study showed that MRI can clearly depict the biodistribution of HoMS, but that quantification by means of the gel calibration curve yields an underestimation that increases for higher amounts of HoMS. The observed underestimation is tentatively attributed to accumulations of HoMS in larger liver vessels. The exploratory quantification experiments suggest the feasibility of MR dosimetry.