Phase II study of KN046 in patients with thymic carcinoma who failed immune checkpoint inhibitors

TPS8607

Background: Thymic carcinomas are the most aggressive form of thymic epithelial tumors. They are often not operable and are more resistant to chemotherapy than thymomas. Thymic carcinoma is sensitive to pembrolizumab. However, most patients who respond to pembrolizumab eventually recur. Recently, molecules that combine PD(L)1 and CTLA-4 have been developed for solid tumor patients, with the hope that targeted therapy will be more effective than standard of care. KN046 is a bi-specific antibody against PD-L1 and CTLA-4 with a much higher affinity of the anti-PD-L1 portion and a weaker affinity for anti-CTLA-4, potentially leading to less autoimmune disorders and toxicities. We developed a Phase II study to test the hypothesis that dual PD-L1 and CTLA-4 inhibition with KN046 may represent a safe and tolerable option for patients with advanced thymic carcinoma who have progressed on prior treatment with immune checkpoint inhibitors. Methods: Key eligibility criteria include thymic carcinoma with progression after treatment with an immune checkpoint inhibitor with no limit to prior lines of therapy, adequate organ function and performance status. History of prior or current autoimmune disorders are not allowed and history of baseline positive anti-acetylcholine receptor (AChR) autoantibody are not allowed. KN046 will be administered intravenously at 5 mg/kg every 2 weeks until progression or excessive toxicity for up to 2 years. A cycle is defined as 2 treatments (28 days). The primary objective is to evaluate the antitumor activity of KN046 in patients with thymic carcinoma as measured by overall response rate defined by RECIST 1.1 criteria. The secondary objectives are to assess the safety and tolerability of KN046 including safety as measured by the number of adverse events (CTCAE 5.0), duration of response (RECIST 1.1) from first documented response to the date of first documented disease progression, progression-free survival, and overall survival. Exploratory objectives include the association of biomarkers (PD-L1 expression, tumor immune microenvironment determined by multiplex IHC, tumor mutational burden, T-cell inflamed gene expression profile) and clinical efficacy parameters. We will also characterize the safety laboratory results (AChR autoantibodies and creatinine kinase) and the occurrence of adverse events of interest. Simon’s two-stage design will be used. The null hypothesis that the true response rate is 5% will be tested against a one-sided alternative of target response rate ≥20%. In the first stage, 10 patients will be accrued. If there are no responses in the first stage, then the study will be stopped. Otherwise, 19 additional patients will be accrued for a total of 29 patients. The null hypothesis will be rejected if ≥4 responses are observed in 29 patients, with a type 1 error rate of 0.05 and power of 80%. The study was activated at Weill Cornell Medicine in December 2021. Clinical trial information: NCT04925947.

Isotope-specific reactions of acetonitrile (CH3CN) with trapped, translationally cold CCl. J Chem Phys 2021;154:074305. [PMID: 33607907 DOI: 10.1063/5.0038113]

The gas-phase reaction of CCl⁺ with acetonitrile (CH₃CN) is studied using a linear Paul ion trap coupled to a time-of-flight mass spectrometer. This work builds on a previous study of the reaction of CCl⁺ with acetylene [K. J. Catani et al., J. Chem. Phys. 152, 234310 (2020)] and further explores the reactivity of CCl⁺ with organic neutral molecules. Both of the reactant species are relevant in observations and models of chemistry in the interstellar medium. Nitriles, in particular, are noted for their relevance in prebiotic chemistry and are found in the atmosphere of Titan, one of Saturn's moons. This work represents one of the first studied reactions of a halogenated carbocation with a nitrile and the first exploration of CCl⁺ with a nitrile. Reactant isotopologues are used to unambiguously assign ionic primary products from this reaction: HNCCl⁺ and C₂H₃ ⁺. Branching ratios are measured, and both primary products are determined to be equally probable. Quantum chemical and statistical reaction rate theory calculations illuminate pertinent information for interpreting the reaction data, including reaction thermodynamics and a potential energy surface for the reaction, as well as rate constants and branching ratios for the observed products. In particular, the reaction products and potential energy surface stimulate questions regarding the strength and role of the nitrile functional group, which can be further explored with more reactions of this class.

Sequential intensive chemotherapy followed by autologous or allogeneic transplantation for refractory lymphoma

We evaluate the safety of bendamustine as a bridge to stem cell transplantation (SCT) in patients with relapsed/refractory lymphoma and residual disease after salvage therapy. Thirty-four subjects without complete responses (CR) received bendamustine 200 mg/m²/day for 2 days followed 14 days later by SCT. Sixteen subjects in partial remission (PR) with maximal FDG-PET SUVs ≤8 prior to bendamustine received autologous SCT, while 13 with suboptimal responses were allografted. Five subjects did not proceed to transplant. No bendamustine toxicities precluded transplantation and no detrimental effect on engraftment or early treatment-related mortality (TRM) was attributable to bendamustine. At 1 year, 75% of auto-recipients and 31% of allo-recipients were alive with CR. Two subjects in the autologous arm developed therapy-related myeloid neoplasia (t-MN). In conclusion, a bendamustine bridge to SCT can be administered without early toxicity to patients with suboptimal responses to salvage chemotherapy. However this approach may increase the risk of t-MN. (NCT02059239).Supplemental data for this article is available online at here.

Current practice patterns for initial umbilical hernia repair in the United States

PURPOSE

The approach to repairing an initial umbilical hernia (IUH) varies substantially, and this likely depends on hernia size, patient age, sex, BMI, comorbidities including diabetes mellitus, and surgeon preference. Of these, only hernia size has been widely studied. This cross-sectional study aims to look at the practice pattern of umbilical hernia repair in the United States.

METHODS

A retrospective study was performed using data from the America Hernia Society Quality Collaborative. Patient characteristics included age, sex, hernia width, BMI, smoking status, and diabetes. Outcomes were use of mesh for repair, as well as surgical approach (open vs minimally invasive). Multivariate logistic regression was performed to assess the independent effect of age, sex, hernia width, BMI, smoking status, and diabetes on use of mesh and approach to repair.

RESULTS

3475 patients were included. 74% were men. Mesh use was more common in men (67% vs 60%, P < 0.001). Mesh was used in 33% of repairs ≤ 1 cm, and 82% of repairs > 1 cm (P < 0.001). Younger patients were less likely to receive a mesh repair (54% if age ≤ 35 vs 67% for age > 35, P < 0.001). However, on multivariate analysis, mesh use was associated with increasing hernia width (OR 5.474, 95% CI 4.7-6.3) as well as BMI (OR 1.8, 95% CI 1.5-2.1) but not with age or sex.

CONCLUSION

The majority of IUH are performed open. Patient BMI and hernia defect size contribute to choice of surgical technique including use of mesh. The use of mesh in 33% of hernias below 1 cm demonstrates a gap between evidence and practice. Patient factors including patient age and sex had no impact on operative approach or use of mesh.

Isomer-selected ion–molecule reactions of acetylene cations with propyne and allene

A combined experimental and quantum chemistry study between sympathetically cooled acetylene cations and propyne or allene explains the dramatically different reaction mechanisms.

Safety and efficacy of plerixafor dose escalation for the mobilization of CD34+ hematopoietic progenitor cells in patients with sickle cell disease: interim results

Gene therapy for sickle cell disease is limited by the yield of hematopoietic progenitor cells that can be harvested for transduction or gene editing. We therefore performed a phase I dose-escalation study of the hematopoietic progenitor cell mobilizing agent plerixafor to evaluate the efficacy and safety of standard dosing on peripheral blood CD34⁺ cell mobilization. Of 15 patients enrolled to date, only one was chronically transfused and ten were on hydroxyurea. Of eight patients who achieved a CD34⁺ cell concentration >30 cells/μL, six were on hydroxyurea. There was no clear dose response to increasing plerixafor dosage. There was a low rate of serious adverse events; two patients developed vaso-occlusive crises, at the doses of 80 μg/kg and 240 μg/kg. Hydroxyurea may have contributed to the limited CD34⁺ mobilization by affecting baseline peripheral blood CD34 counts, which correlated strongly with peak peripheral blood CD34 counts. Plerixafor administration did not induce significant increases in the fraction of activated neutrophils, monocytes, or platelets. However, increased neutrophils positive for activated β2 integrin and Mac-1 were associated with serious adverse events. In summary, plerixafor was well tolerated but did not achieve consistent CD34⁺ cell mobilization in this cohort of patients, most of whom were being actively treated with hydroxyurea and only one was chronically transfused. The study will continue with escalation of the dose of plerixafor and modification of hydroxyurea administration. Clinicaltrials.gov identifier: NCT02193191.

An ion trap time-of-flight mass spectrometer with high mass resolution for cold trapped ion experiments

Trapping molecular ions that have been sympathetically cooled with laser-cooled atomic ions is a useful platform for exploring cold ion chemistry. We designed and characterized a new experimental apparatus for probing chemical reaction dynamics between molecular cations and neutral radicals at temperatures below 1 K. The ions are trapped in a linear quadrupole radio-frequency trap and sympathetically cooled by co-trapped, laser-cooled, atomic ions. The ion trap is coupled to a time-of-flight mass spectrometer to readily identify product ion species and to accurately determine trapped ion numbers. We discuss, and present in detail, the design of this ion trap time-of-flight mass spectrometer and the electronics required for driving the trap and mass spectrometer. Furthermore, we measure the performance of this system, which yields mass resolutions of m/Δm ≥ 1100 over a wide mass range, and discuss its relevance for future measurements in chemical reaction kinetics and dynamics.

Combined Haploidentical and Umbilical Cord Blood Allogeneic Stem Cell Transplantation for High-Risk Lymphoma and Chronic Lymphoblastic Leukemia

Limited studies have reported on outcomes for lymphoid malignancy patients receiving alternative donor allogeneic stem cell transplants. We have previously described combining CD34-selected haploidentical grafts with umbilical cord blood (haplo-cord) to accelerate neutrophil and platelet engraftment. Here, we examine the outcome of patients with lymphoid malignancies undergoing haplo-cord transplantation at the University of Chicago and Weill Cornell Medical College. We analyzed 42 lymphoma and chronic lymphoblastic leukemia (CLL) patients who underwent haplo-cord allogeneic stem cell transplantation. Patients underwent transplant for Hodgkin lymphoma (n = 9, 21%), CLL (n = 5, 12%) and non-Hodgkin lymphomas (n = 28, 67%), including 13 T cell lymphomas. Twenty-four patients (52%) had 3 or more lines of therapies. Six (14%) and 1 (2%) patients had prior autologous and allogeneic stem cell transplant, respectively. At the time of transplant 12 patients (29%) were in complete remission, 18 had chemotherapy-sensitive disease, and 12 patients had chemotherapy-resistant disease. Seven (17%), 11 (26%), and 24 (57%) patients had low, intermediate, and high disease risk index before transplant. Comorbidity index was evenly distributed among 3 groups, with 13 (31%), 14 (33%), and 15 (36%) patients scoring 0, 1 to 2, and ≥3. Median age for the cohort was 49 years (range, 23 to 71). All patients received fludarabine/melphalan/antithymocyte globulin conditioning regimen and post-transplant graft-versus-host disease (GVHD) prophylaxis with tacrolimus and mycophenolate mofetil. The median time to neutrophil engraftment was 11 days (range, 9 to 60) and to platelet engraftment 19.5 days (range, 11 to 88). Cumulative incidence of nonrelapse mortality was 11.6% at 100 days and 19 % at one year. Cumulative incidence of relapse was 9.3% at 100 days and 19% at one year. With a median follow-up of survivors of 42 months, the 3-year rates of GVHD relapse free survival, progression-free survival, and overall survival were 53%, 62%, and 65%, respectively, for these patients. Only 8% of the survivors had chronic GVHD. In conclusion, haplo-cord transplantation offers a transplant alternative for patients with recurrent or refractory lymphoid malignancies who lack matching donors. Both neutrophil and platelet count recovery is rapid, nonrelapse mortality is limited, excellent disease control can be achieved, and the incidence of chronic GVHD is limited. Thus, haplo-cord achieves high rates of engraftment and encouraging results.

A Phase I Trial of High-Dose Lenalidomide and Melphalan as Conditioning for Autologous Stem Cell Transplantation in Relapsed or Refractory Multiple Myeloma

Autologous stem cell transplantation (ASCT) conditioned with high-dose chemotherapy has long been established as the standard of care for eligible patients with newly diagnosed multiple myeloma. Despite recent therapeutic advances, high-dose melphalan (HDM) remains the chemotherapy regimen of choice in this setting. Lenalidomide (LEN) in combination with low-dose dexamethasone is recognized as a standard of care for patients with relapsed or refractory multiple myeloma (RRMM), and there is growing support for the administration of LEN as maintenance therapy post-ASCT. In view of the above, the present phase I clinical trial was designed to evaluate the safety and tolerability of high-dose LEN (HDLEN) in patients with RRMM, and to determine the maximum tolerated dose of HDLEN when added to HDM before ASCT. Despite administering HDLEN at doses of up to 350 mg/day, the maximum tolerated dose could not be determined, owing to an insufficient number of dose-limiting toxicities in the 21 patients enrolled in the trial. Conditioning with HDLEN plus HDM was associated with a favorable tolerability profile. Adverse events following ASCT were as expected with HDM. Median progression-free and overall survival were 10 months and 22 months, respectively, in this population of heavily pretreated patients. Our findings suggest that HDLEN in combination with HDM may offer significant potential as a conditioning regimen before ASCT in patients with RRMM. These preliminary findings are now being evaluated further in an ongoing phase II clinical trial.

Atmospheric benzenoid emissions from plants rival those from fossil fuels

Despite the known biochemical production of a range of aromatic compounds by plants and the presence of benzenoids in floral scents, the emissions of only a few benzenoid compounds have been reported from the biosphere to the atmosphere. Here, using evidence from measurements at aircraft, ecosystem, tree, branch and leaf scales, with complementary isotopic labeling experiments, we show that vegetation (leaves, flowers, and phytoplankton) emits a wide variety of benzenoid compounds to the atmosphere at substantial rates. Controlled environment experiments show that plants are able to alter their metabolism to produce and release many benzenoids under stress conditions. The functions of these compounds remain unclear but may be related to chemical communication and protection against stress. We estimate the total global secondary organic aerosol potential from biogenic benzenoids to be similar to that from anthropogenic benzenoids (~10 Tg y⁻¹), pointing to the importance of these natural emissions in atmospheric physics and chemistry.

Phase I study of the anti-CD74 monoclonal antibody milatuzumab (hLL1) in patients with previously treated B-cell lymphomas

Milatuzumab (hLL1), a humanized anti-CD74 monoclonal antibody, has activity in preclinical non-Hodgkin lymphoma (NHL) models. We conducted a phase 1 trial in previously treated B-cell malignancies. Dose escalation included four planned dose levels (1.5, 4, 6 and 8 mg/kg) with milatuzumab given twice weekly for 6 weeks. After dose level 1, the schedule was changed to daily (Monday-Friday) for 10 days. Twenty-two patients were treated. The most common possibly related toxicities were infusion reaction, anemia, lymphopenia, neutropenia and thrombocytopenia. Three patients experienced dose-limiting toxicity (neutropenia, neutropenia, rash) at dose levels 1, 2 and 4, respectively. Eight patients had stable disease, with no objective responses. The serum half-life of milatuzumab was ∼2 h. In seven patients, In-111 imaging showed no clear evidence of tumor targeting. The short half-life may reflect CD74 rapid internalization and presence on extratumoral tissues; this antigen sink must be overcome to capitalize on the promising preclinical activity of the drug.

Phase 1 study of radiosensitization using bortezomib in patients with relapsed non-Hodgkin lymphoma receiving radioimmunotherapy with 131I-tositumomab

Radioimmunotherapy (RIT) is effective treatment for indolent non-Hodgkin lymphomas (NHLs), but response durations are usually limited, especially in aggressive NHL. We hypothesized that administration of bortezomib as a radiosensitizer with RIT would be tolerable and improve efficacy in NHL. This phase 1 dose-escalation study evaluated escalating doses of bortezomib combined with 131I-tositumomab in patients with relapsed/refractory NHL. Twenty-five patients were treated. Treatment was well tolerated, with primarily hematologic toxicity. The maximum tolerated dose (MTD) was determined to be 0.9 mg/m2 bortezomib, in combination with a standard dose of 75 cGy 131I-tositumomab. Sixteen patients responded (64%), including 44% complete responses (CRs), with 82% CR in patients with follicular lymphoma (FL). At a median follow-up of 7 months, median progression-free survival was 7 months, and seven of 11 patients with FL remained in remission at a median of 22 months. In conclusion, bortezomib can be safely administered in combination with 131I-tositumomab with promising response rates.