Citations

Background L-MIND (NCT02399085) is an ongoing, open-label, single-arm, Phase II study of tafasitamab + lenalidomide (LEN) in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who are ineligible for autologous stem cell transplant. Progression-free survival (PFS) estimates the treatment effect of the study drug only, while overall survival (OS) also includes effects of potential subsequent cancer treatments or palliative care. Given that not all OS and PFS events have occurred after a long follow-up duration, traditional survival analyses may underestimate survival benefit for tafasitamab + LEN by assuming the same mortality rate for the whole population. We used mixture cure models to estimate the proportion of long-term survivors (LTS) and survival benefit associated with tafasitamab + LEN treatment. Methods In the L-MIND study (data cut-off: Nov 30, 2019), 80/81 enrolled patients with R/R DLBCL received tafasitamab + LEN, with a median and maximum follow-up duration of 31.8 months (95% CI: 27.2-35.9) and 43.5 months, respectively. The Kaplan-Meier (KM) plots of PFS and OS were observed to plateau after 30 months, with the majority of events reported up to that time-point and very few events beyond this time-point. Patients without a PFS event or patients who did not decease after the observed plateau exhibit a high survival benefit from tafasitamab + LEN treatment and are considered LTS. Thus, the patient population can be considered to consist of two sub-populations - LTS and non-LTS. A "mixture cure model" was fitted on the PFS and OS data to estimate the proportion of LTS and associated mean survival for the two sub-populations (Lambert PC, et al. 2007). To incorporate background mortality (Bansal, et al. 2019), age- and sex-specific US mortality rates (US CDC 2017) were factored in for the entire study population (enrolled in Europe and US). The weighted average of the mean survival for the two sub-populations provided an estimate of the mean survival for the whole population. For comparative purposes, standard parametric models without considering an LTS proportion were fitted on PFS and OS data additionally. Sensitivity analyses were performed considering different survival distributions (exponential distribution, Weibull distribution and log-logistic distribution). Results By using a mixture cure model fitted to PFS and OS data separately, the estimated proportion of LTS for the tafasitamab + LEN combination was 42% (95% CI: 30-55) and 47% (95% CI: 29-66), respectively. The predicted mean survival when mixture cure model was fitted on PFS data was 16.7 years for LTS patients vs 0.5 years for non-LTS patients, yielding 7.3 years for the overall population. Under this mixture cure model, the survival rates of patients with tafasitamab + LEN treatment were 40.2% and 36.0% at 2 and 5 years. Similar results were obtained when the mixture cure model was fitted on OS data. Using a standard parametric model (Weibull distribution), the predicted mean survival in the overall population was 2.8 years fitting PFS data (Figure 1) and 4.5 years fitting OS data (Figure 2). Conclusions PFS and OS KM curves for the L-MIND study reaching a long plateau and not following a Weibull distribution suggest the presence of an LTS subgroup. Standard parametric models may lead to a biased estimation of the OS benefit in such situations. The mixture cure model suggests that the treatment of R/R DLBCL patients with tafasitamab + LEN is associated with a high LTS proportion. The survival rates of patients with tafasitamab + LEN treatment were 40.2% and 36.0% at 2 and 5 years. Disclosures Salles: Takeda:Honoraria;BMS/Celgene:Honoraria, Other: consultancy or advisory role;Debiopharm:Consultancy, Honoraria, Other: consultancy or advisory role;Genmab:Honoraria, Other;Karyopharm:Honoraria;Kite, a Gilead Company:Honoraria, Other: consultancy or advisory role ;Epizyme:Honoraria, Other: consultancy or advisory role;Janssen:Honoraria, Other: consultancy or advisory role;Abbvie:Other: consultancy or advisory role;Roche:Honoraria, Other: consultancy or advisory role;Novartis:Honoraria, Other: consultancy or advisory role;MorphoSys:Honoraria, Other: consultancy or advisory role;Autolos:Other: consultancy or advisory role.Goswami:MorphoSys AG:Ended employment in the past 24 months.Bagnardi:MorphoSys AG:Consultancy.Dey:MorphoSys AG:Current Employment.Winderlich:MorphoSys AG:Current Employment.Ambarkhane:MorphoSys AG:Current Employment.Huang:MorphoSys AG:Current Employment.Nowakowski:Curis:Consultancy;Kymera:Consultancy;Kite:Consultancy;Ryvu:Consultancy, Membership on an entity's Board of Directors or advisory committees;Celgene/BMS:Consultancy, Research Funding;Seattle Genetics:Consultancy;MorphoSys:Consultancy, Research Funding;NanoString:Research Funding.

Background: PT-112 is a novel pyrophosphate-platinum conjugate with a multi-modal mechanism of action that induces immunogenic cell death and is not susceptible to DNA-repair drug resistance pathways. In phase I studies in solid tumors, PT-112 demonstrated safety and efficacy as single agent and in combination with PD-L1 checkpoint inhibitor avelumab, crossing a range of dose levels (DL) and tumor types, including in heavily pre-treated patients (pts) non-responsive to immunotherapy and refractory to other modalities. Non-clinical, in vivo research using advanced imaging technology demonstrated that PT-112 reached the highest concentrations in bone tissue (osteotropism). Moreover, PT-112 was highly active in the orthotopic, immune-competent Vk*MYC mouse model of multiple myeloma, including drug-resistant transplant variants. Thus, a rationale for PT-112 as an investigational candidate in multiple myeloma was established. Here, we present results of a phase I dose escalation study of PT-112 in pts with relapsed or refractory multiple myeloma (RRMM). Methods: A 3+3 design was used to determine the recommended phase 2 dose (RP2D) for PT-112 (28-day cycle IV days 1, 8, 15) in pts with evaluable RRMM who had exhausted available therapies (Tx), with adequate bone marrow (abs neutrophil count ≥ 1.0 x 109/L; platelet count ≥ 50 x 109/L; and hemoglobin ≥ 8.0 g/dL) and renal function (calculated creatinine clearance ≥ 30 mL/min), and ECOG PS 0-2. Results: A total of 24 pts were treated with PT-112 monotherapy across 6 DLs: 125 mg/m2, 3 pts; 180 mg/m2, 4 pts; 250 mg/m2, 5 pts; 300 mg/m2, 4 pts; 360 mg/m2, 4 pts; 420 mg/m2, 4 pts. Patients had a median age of 72 years and were heavily pre-treated, with a median of 8 prior lines of systemic Tx: 22 (92%) pts were triple-class refractory with 19 (79%) pts penta-refractory, and 3 (13%) pts refractory to BCMA-based therapies. The most common treatment-related adverse events (TRAEs) were thrombocytopenia (58%), neutropenia (42%), diarrhea (38%), and nausea (38%). 38% of pts had ≥1 grade 3 non-hematologic TRAE, with no grade 4 non-hematologic TRAEs reported. One dose-limiting toxicity (DLT) of grade 4 neutropenia occurred at the 420 mg/m2 DL. In addition, due to frequent dose reductions and modifications at this DL, the safety committee declared 360 mg/m2 as the RP2D. Among 8 patients who received a starting dose at / above the RP2D, 2 had stable disease and 4 experienced responses to PT-112 Tx. These included a confirmed partial response (PR) achieved in a 79-year-old pt with kappa free light chain (FLC) disease treated at 360 mg/m2, whose previous Tx included combination regimens with most approved therapies (penta-refractory) and stem cell transplantation. FLC levels declined by 65% from baseline on PT-112 therapy and the pt remained progression free for 4.5 months. A 72-year-old pt treated at the 420 mg/m2 DL, reduced to 250mg/m2 every other week over the course of Tx due to grade 3-4 cytopenias, had a confirmed minor response. Prior Tx with multiple lines given over 9 years included stem cell transplantation, most approved therapies (penta-refractory), prior investigational antibody and CAR-T cell Tx (primary refractory to CAR-T). The patient was M-protein negative, kappa FLC levels declined by 32% following the first dose reduction, and the pt remained progression free and clinically stable without complaints for 4.5 months. Additionally, two transient, unconfirmed PRs occurred in patients at the 420mg/m2 DL: in a triple-class-refractory 82-year-old previously treated with 5 lines of Tx, with 70% reduction in kappa FLC during cycle 1; and in a penta-refractory 85-year-old, who experienced disappearance of M-protein during cycle 1 and Gr 4 neutropenia (DLT). Conclusions: PT-112 monotherapy was feasible and well tolerated in this heavily pre-treated, multi-refractory multiple myeloma population, and the Phase I clinical data appear to validate the developmental hypothesis, built upon activity in the Vk*MYC mouse model of multiple myeloma. Responses were confirmed in 25% of patients treated at / above the RP2D using single-agent PT-112, an encouraging result in a dose escalation trial conducted in heavily refractory patients. Activity of PT-112 in RRMM patients may be explained by its osteotropism and its unique mechanism of action compared to other drug classes used to treat this disease. Further clinical study of PT-112 in RRMM is warranted in a phase 2 clinical trial. Disclosures Ailawadhi: Celgene: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Amgen: Research Funding; Medimmune: Research Funding; BMS: Research Funding; Cellectar: Research Funding; Phosplatin: Research Funding; Takeda: Honoraria. Vogl:Janssen: Consultancy; Celgene: Consultancy; MorphoSys: Consultancy; Takeda: Consultancy; Active Biotech: Consultancy, Research Funding; Oncopeptides: Consultancy; Karyopharm: Consultancy. Ames:Phosplatin Therapeutics: Current Employment, Current equity holder in private company. Yim:Phosplatin Therapeutics: Current Employment, Current equity holder in private company. Price:Phosplatin Therapeutics: Current Employment, Current equity holder in private company. Jimeno:Phosplatin Therapeutics: Current Employment, Current equity holder in private company.

Abstract Tumor mutational burden (TMB), defined as the number of somatic mutations per megabase of interrogated genomic sequence, varies across malignancies. Panel sequencing–based estimates of TMB have largely replaced whole-exome sequencing–derived TMB in the clinic. Retrospective evidence suggests that TMB can predict the efficacy of immune checkpoint inhibitors, and data from KEYNOTE-158 led to the recent FDA approval of pembrolizumab for the TMB-high tumor subgroup. Unmet needs include prospective validation of TMB cutoffs in relationship to tumor type and patient outcomes. Furthermore, standardization and harmonization of TMB measurement across test platforms are important to the successful implementation of TMB in clinical practice. Significance: Evaluation of TMB as a predictive biomarker creates the need to harmonize panel-based TMB estimation and standardize its reporting. TMB can improve the predictive accuracy for immunotherapy outcomes, and has the potential to expand the candidate pool of patients for treatment with immune checkpoint inhibitors.

Abstract Viruses spread between hosts through particles, but within hosts, viral genomes can spread from cell to cell through fusion, evading antiviral defenses and obviating costly infectious virion production1-3. Billions of electromechanically coupled cardiomyocytes (CMs) make myocardium inherently vulnerable to pathological electromechanical short circuits caused by intercellular viral spread 4-6. Beyond respiratory illness, COVID-19 affects the heart7 and cardiac injury and arrhythmias are serious public health concerns8-12. By studying myocardium of a young woman who died suddenly, diagnosed postmortem with COVID-19, we discovered highly focal myocardial SARS-CoV-2 infection spreading from one CM to another through intercellular junctions identified by highly concentrated sarcolemmal t-tubule viral spike glycoprotein. SARS-CoV-2 permissively infected beating human induced pluripotent stem cell (hiPSC)-CMs building multinucleated cardiomyotubes (CMTs) through cell type-specific fusion driven by proteolytically-activated spike glycoprotein. Recombinant spike glycoprotein, co-localizing to sarcolemma and sarcoplasmic reticulum, produced multinucleated CMTs with pathological structure, electrophysiology and Ca2+ excitation-contraction coupling. Blocking cleavage, a peptide-based protease inhibitor neutralized SARS-CoV-2 spike glycoprotein pathogenicity. We conclude that SARS-CoV-2 spike glycoprotein, efficiently primed, activated and strategically poised during biosynthesis, can exploit the CM’s inherent membranous connectivities to drive heart damage directly, uncoupling clinically common myocardial injury from lymphocytic myocarditis, often suspected but rarely confirmed in COVID-19.

Abstract The results from the RATIFY trial (ClinicalTrials.gov: NCT00651261; CALGB 10603) showed that midostaurin combined with standard chemotherapy significantly improved outcomes in patients with FMS-like tyrosine kinase 3 (FLT3)–mutated acute myeloid leukemia (AML), compared with placebo. In this post hoc subgroup analysis from the trial, we evaluated the impact of midostaurin in 163 patients with FLT3-tyrosine kinase domain (TKD) mutations. At a median follow-up of 60.7 months (95% CI, 55.0-70.8), the 5-year event-free survival (EFS) rate was significantly higher in patients treated with midostaurin than in those treated with placebo (45.2% vs 30.1%; P = .044). A trend toward improved disease-free survival was also observed with midostaurin (67.3% vs 53.4%; P = .089), whereas overall survival (OS) was similar in the 2 groups. Patients with AML and NPM1mut/FLT3-TKDmut or core binding factor (CBF)–rearranged/FLT3-TKDmut genotypes had significantly prolonged OS with or without censoring at hematopoietic cell transplantation (HCT), compared with NPM1WT/CBF-negative AMLs. The multivariable model for OS and EFS adjusted for allogeneic HCT in first complete remission as a time-dependent covariable, revealed NPM1 mutations and CBF rearrangements as significant favorable factors. These data show that NPM1 mutations or CBF rearrangements identify favorable prognostic groups in patients with FLT3-TKD AMLs, independent of other factors, also in the context of midostaurin treatment.

ABSTRACT Background There is only partial overlap in the genetic background of isolated rapid‐eye‐movement sleep behavior disorder (iRBD) and Parkinson's disease (PD). Objective To examine the role of autosomal dominant and recessive PD or atypical parkinsonism genes in the risk of iRBD. Methods Ten genes, comprising the recessive genes PRKN , DJ‐1 (PARK7) , PINK1 , VPS13C , ATP13A2 , FBXO7 , and PLA2G6 and the dominant genes LRRK2 , GCH1 , and VPS35 , were fully sequenced in 1039 iRBD patients and 1852 controls of European ancestry, followed by association tests. Results We found no association between rare heterozygous variants in the tested genes and risk of iRBD. Several homozygous and compound heterozygous carriers were identified, yet there was no overrepresentation in iRBD patients versus controls. Conclusion Our results do not support a major role for variants in these genes in the risk of iRBD. © 2020 International Parkinson and Movement Disorder Society

AbstractBackgroundAggressive dose de‐escalated adjuvant radiation therapy (RT) in patients with human papillomavirus–associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC).MethodsPatients with HPV(+)OPSCC on a phase II clinical trial of primary surgery and neck dissection followed by dose de‐escalated RT (N = 79) were compared with a cohort of patients who received standard adjuvant therapy (N = 115). Local recurrence‐free, regional recurrence‐free, distant metastases‐free survival, and progression‐free survival (PFS) were assessed.ResultsOf 194 patients, 23 experienced progression at a median of 1.1 years following surgery (interquartile range [IQR] 0.7‐2.0; range 0.3‐5.4); 10 patients in the de‐escalated cohort and 13 patients in the standard cohort. The 3‐year PFS rate for the de‐escalated cohort was 87%, and in the standard cohort was 90% (hazard ratio [HR] 1.18, 95% confidence interval (CI) [0.50‐2.75]).ConclusionPatients with HPV(+)OPSCC who undergo surgical resection and neck dissection and meet criteria for adjuvant therapy can undergo aggressive dose de‐escalation of RT without increasing risk of progression locally, regionally or at distant sites.

Background: The KCNH2 -encoded Kv11.1 hERG (human ether-a-go-go related gene) potassium channel is a critical regulator of cardiomyocyte action potential duration (APD). The majority of type 2 long-QT syndrome (LQT2) stems from trafficking defective KCNH2 mutations. Recently, Food and Drug Administration-approved cystic fibrosis protein trafficking chaperone, lumacaftor, has been proposed as novel therapy for LQT2. Here, we test the efficacy of lumacaftor treatment in patient-specific induced pluripotent stem cell-cardiomyocytes (iPSC-CMs) derived from 2 patients with known LQT2 trafficking defective mutations and a patient with novel KCNH2 variant, p.R685P. Methods: Patient-specific iPSC-CM models of KCNH2-G604S, KCNH2-N633S, and KCNH2-R685P were generated from 3 unrelated patients diagnosed with severe LQT2 (rate-corrected QT>500 ms). Lumacaftor efficacy was also tested by ANEPPS, FluoVolt, and ArcLight voltage dye-based APD90 measurements. Results: All 3 mutations were hERG trafficking defective in iPSC-CMs. While lumacaftor treatment failed to rescue the hERG trafficking defect in TSA201 cells, lumacaftor rescued channel trafficking for all mutations in the iPSC-CM model. All 3 mutations conferred a prolonged APD90 compared with control. While lumacaftor treatment rescued the phenotype of KCNH2-N633S and KCNH2-R685P, lumacaftor paradoxically prolonged the APD90 in KCNH2-G604S iPSC-CMs. Lumacaftor-mediated APD90 rescue was affected by rapidly activating delayed rectifier K+ current blocker consistent with the increase of rapidly activating delayed rectifier K+ current by lumacaftor is the underlying mechanism of the LQT2 rescue. Conclusions: While lumacaftor is an effective hERG channel trafficking chaperone and may be therapeutic for LQT2, we urge caution. Without understanding the functionality of the mutant channel to be rescued, lumacaftor therapy could be harmful.