Population pharmacokinetics and exposure-response analyses of polatuzumab vedotin in patients with previously untreated DLBCL from the POLARIX study

Polatuzumab vedotin is a CD79b-directed antibody-drug conjugate that targets B cells and delivers the cytotoxic payload monomethyl auristatin E (MMAE). The phase III POLARIX study (NCT03274492) evaluated polatuzumab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHP) as first-line treatment of diffuse large B-cell lymphoma (DLBCL). To examine dosing decisions for this regimen, population pharmacokinetic (popPK) analysis, using a previously developed popPK model, and exposure-response (ER) analysis, were performed. The popPK analysis showed no clinically meaningful relationship between cycle 6 (C6) antibody-conjugated (acMMAE)/unconjugated MMAE area under the concentration-time curve (AUC) or maximum concentration, and weight, sex, ethnicity, region, mild or moderate renal impairment, mild hepatic impairment, or other patient and disease characteristics. In the ER analysis, C6 acMMAE AUC was significantly associated with longer progression-free and event-free survival (both p = 0.01). An increase of <50% in acMMAE/unconjugated MMAE exposure did not lead to a clinically meaningful increase in adverse events of special interest. ER data and the benefit-risk profile support the use of polatuzumab vedotin 1.8 mg/kg once every 3 weeks with R-CHP for six cycles in patients with previously untreated DLBCL.

Application of systems biology to identify pharmacological mechanisms of thrombotic microangiopathy evoked by combined activated prothrombin complex concentrate and emicizumab

Emicizumab is a bispecific monoclonal antibody that substitutes for the function of missing or deficient factor VIII (FVIII) in people with hemophilia A (PwHA). Long-term safety and efficacy of emicizumab have been demonstrated in several clinical trials. Nevertheless, in the first of these, three cases of thrombotic microangiopathy (TMA) occurred in PwHA treated with emicizumab receiving high doses of activated prothrombin complex concentrate (aPCC), a bypassing agent used for treating breakthrough bleeds when FVIII neutralizing antibodies (inhibitors) make FVIII replacement ineffective. The aim of the present work is to offer a method to elucidate the pathophysiological and pharmacological mechanisms involved in this treatment-induced TMA. Systems biology and machine learning-based Therapeutic Performance Mapping System is a validated in silico technology that allowed us to construct models of potential mechanisms behind induced TMA. Two drug combinations were modeled and assessed: emicizumab plus aPCC and emicizumab plus recombinant activated factor VII (another bypassing agent). Our models showed that both combinations were related to activation of the coagulation cascade. However, mechanisms involved mainly in platelet activation and possibly in complement activation were detected only for emicizumab plus aPCC, potentially explaining the occurrence of TMA only in this combination.

Integrated summary of immunogenicity of polatuzumab vedotin in patients with relapsed or refractory B-cell non-Hodgkin’s lymphoma

Polatuzumab vedotin, marketed under the trade name POLIVY®, is a CD79b-targeted antibody-drug conjugate that preferentially delivers a potent anti-mitotic agent (monomethyl auristatin E) to B cells, resulting in anti-cancer activity against B-cell malignancies. In 2019, polatuzumab vedotin in combination with rituximab and bendamustine was approved by the United States Food and Drug Administration for the treatment of adult patients with diffuse large B-cell lymphoma who have received at least two prior therapies. Recent Health Authority guidance recommendations for submitting an Integrated Summary of Immunogenicity were followed including a comprehensive immunogenicity risk assessment, bioanalytical strategy, and immunogenicity data to support the registration of polatuzumab vedotin. Key components of the polatuzumab vedotin Integrated Summary of Immunogenicity and data are presented. Validated semi-homogeneous bridging enzyme-linked immunosorbent assays were used to detect anti-drug antibodies (ADA) to polatuzumab vedotin and characterize the immune response in patients with non-Hodgkin’s lymphoma. The overall incidence of ADA observed for polatuzumab vedotin was low across seven clinical trials. The low incidence of ADA is likely due to the mechanism of action of polatuzumab vedotin that involves targeting and killing of B cells, thereby limiting the development to plasma cells and ADA secretion. Furthermore, patients are co-medicated with rituximab, which also targets B cells and results in B-cell depletion. Therefore, the immunogenicity risk is considered low and not expected to impact the polatuzumab vedotin benefit/risk profile.

Analysis of peripheral neuropathy (PN) using clinician- and patient-reported outcomes (ClinRO and PRO) in the POLARIX study

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Background: PN is an identified risk of anti-microtubule agents, including polatuzumab vedotin and vincristine. POLARIX (NCT03274492), a Phase III randomized, double-blind, placebo-controlled study comparing Pola-R-CHP with R-CHOP, demonstrated improved progression-free survival (PFS) with Pola-R-CHP (Tilly et al. NEJM 2022). Here, we evaluate the impact of Pola-R-CHP vs R-CHOP on PN using ClinRO and PRO data. Methods: Patients with previously untreated diffuse large B-cell lymphoma (DLBCL) received Pola-R-CHP or R-CHOP. ClinRO data were based on PN grading according to the NCI CTCAE v4.0. PRO data were generated from assessment of patient-reported PN symptoms at baseline and Day 1 of each cycle using the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group – Neurotoxicity (FACT-GOG/NTX) subscale, ranging from 0–44, with higher scores representing lower levels of PN (minimal clinically important difference: 1.38–3.68 [Cheng et al. Health Qual Life Outcomes 2020]). Results: At baseline, ClinRO and PRO symptom scores showed low PN burden (Table). Overall incidence of PN was comparable between treatment arms (Pola-R-CHP: 52.9%; R-CHOP: 53.9%); most events were grade 1, and incidence of grade 2 (Pola-R-CHP: 12.2%; R-CHOP: 15.5%) and grade 3 (Pola-R-CHP: 1.6%; R-CHOP: 1.1%) events were comparable between treatment arms. FACT-GOG/NTX survey completion was high in both arms (96% at baseline; >80% at other timepoints). When evaluated by cycle, ClinRO and PRO demonstrated that more patients experienced earlier onset PN with R-CHOP than with Pola-R-CHP (Table), with ̃10% more R-CHOP- than Pola-R-CHP-treated patients having clinician-reported PN in Cycle (C) 2–5, and a ̃+1-point difference (i.e. fewer symptoms) in PRO symptom scores in C3–6 with Pola-R-CHP vs R-CHOP; by C8+, and during follow up, rates and symptoms of PN were similar. PN symptoms resulted in fewer dose reductions (3.9% vs 8.2%) and drug discontinuations (0.7% vs 2.1%) with Pola-R-CHP vs R-CHOP. Duration of PN was similar for both treatments. Conclusions: In the POLARIX study, Pola-R-CHP did not result in different rates or severity of PN vs R-CHOP. According to ClinRO and PRO data, PN occurred later following initial exposure to Pola-R-CHP than to R-CHOP, and there were fewer dose modifications with Pola-R-CHP than with R-CHOP. Overall, the risk of PN was manageable. Clinical trial information: NCT03274492. [Table: see text]

Fabrication of reproducible, integration-compatible hybrid molecular/si electronics

Reproducible molecular junctions can be integrated within standard CMOS technology. Metal-molecule-semiconductor junctions are fabricated by direct Si-C binding of hexadecane or methyl-styrene onto oxide-free H-Si(111) surfaces, with the lateral size of the junctions defined by an etched SiO2 well and with evaporated Pb as the top contact. The current density, J, is highly reproducible with a standard deviation in log(J) of 0.2 over a junction diameter change from 3 to 100 μm. Reproducibility over such a large range indicates that transport is truly across the molecules and does not result from artifacts like edge effects or defects in the molecular monolayer. Device fabrication is tested for two n-Si doping levels. With highly doped Si, transport is dominated by tunneling and reveals sharp conductance onsets at room temperature. Using the temperature dependence of current across medium-doped n-Si, the molecular tunneling barrier can be separated from the Si-Schottky one, which is a 0.47 eV, in agreement with the molecular-modified surface dipole and quite different from the bare Si-H junction. This indicates that Pb evaporation does not cause significant chemical changes to the molecules. The ability to manufacture reliable devices constitutes important progress toward possible future hybrid Si-based molecular electronics.

The administration of general anesthesia to a patient with croup

Croup in a young child may lead to severe airway narrowing, and would present a severe risk for administration of anesthesia. To the best of our knowledge, there have been no previous case reports of patients undergoing general anesthesia with croup. In our report, we describe a case of a 31 month old child with croup who required anesthesia.

[In vitro model of hyperacute rejections in swine to human xenotransplantation]

OBJECTIVE

To evaluate the efficiency of inhibiting hyperacute rejections in swine to human xenotransplantation through expressing human CD(59) protein on the membrane of cultured pig aortic endothelial cells (PAECs) by transgenic methods.

METHODS

The cultured PAECs and human umbilical vein endothelial cells (HUVECs) were identified by fluorescent and immunohistochemical methods. The constructed eukaryorotic expression vectors containing the human CD(59) cDNA, LXSN-CD(59) were identified by the methods of restriction endonucleases cleavage, agarose gel electrophoresis, and polymerase chain reaction. LXSN and LXSN-CD(59) were transfected into the PAECs separately with lipofectinmine mediated method. Stable transfectants were selected using G418. Cells expressing maximum human CD(59) protein were selected by FACS. These clones were incubated with the media containing human serum or monkey serum. The LDH released into the media was measured to assess the function of the hCD(59) protein.

RESULT

Comparing with the control cells, we found that the cells expressing the human CD(59) protein released less LDH when they were incubated with human serum or monkey serum (P < 0.01).

CONCLUSION

Hyperacute rejections may be inhibited through expressing the human complement regulatory protein CD(59) on the membrane of PAECs by transgenic methods.

Effects of SO2 exposure on canine pulmonary epithelial functions

We examined the effects of a single exposure of high concentrations of sulfur dioxide (SO2) on the pulmonary epithelium in adult dogs over a period of several weeks. Mucociliary tracheal transport rates and alveolar clearance of 99mTc-labeled diethylene triamine pentacetate (99mTcO4-) were measured in vivo, before and immediately after inhalation of 100 ppm or 500 ppm SO2, and then weekly for 3-5 weeks. At the completion of the in vivo studies, tracheal epithelium was studied in Ussing chambers for bioelectric properties (short-circuited current, transepithelial potential difference), nonelectrolyte permeability for calculation of pore sizes, and changes in bioelectric properties following pharmacological manipulations. These tissues were then fixed for scanning electron microscopy studies. Additional dogs were sacrificed for microscopy studies at several time intervals to provide a histological basis for the altered mucociliary transport. We found that despite marked derangement of mucociliary transport caused by damage to the ciliated cells, recovery occurred over a period of several weeks, and alveolar permeability as assessed by the radioaerosol technique did not change. We concluded that the solubility of SO2 and perhaps a more severe damaging effect of SO2 specific on the ciliated cells might be the explanation for the observations.

Fluorescence bronchoscopy in the localization of bronchogenic carcinoma

Fluorescence bronchoscopy using hematoporphyrin derivative as a tumor marker has been developed for localization of early bronchogenic carcinoma. Recent clinical results have been obtained with a krypton laser and a fused quartz fiber illumination system, which is clearly superior to the mercury vapor lamp system used previously. Fifteen patients have been examined, two with the laser. The potential of the technique is demonstrated by a case study of a patient with positive sputum cytology and a negative chest radiograph. The small early invasive tumor could be detected only with difficulty by subtle mucosal changes under white light bronchoscopy. Positive fluorescence was observed in the suspicious area. Malignancy was confirmed by biopsy and histologic examination upon subsequent lobectomy.