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Background: Umbralisib (TGR-1202) is a novel next-generation inhibitor of phosphatidylinositol 3-kinase (PI3K) isoform p110δ (PI3Kδ), which is structurally distinct from other PI3Kδ inhibitors and shows improved isoform selectivity. Umbralisib also uniquely inhibits casein kinase-1ε, a major regulator of protein translation. The aim of this first-in-human phase 1 study was to establish the safety and preliminary activity profile of umbralisib in patients with haematological malignancies.Methods: We did an open-label, phase 1, dose-escalation study at seven clinics in the USA. We recruited patients aged at least 18 years with relapsed or refractory chronic lymphocytic leukaemia or small lymphocytic lymphoma, B-cell and T-cell non-Hodgkin lymphoma, or Hodgkin's lymphoma, who had received one or more previous lines of therapy, with measurable and assessable disease, and adequate organ system function. Patients self-administered an umbralisib oral tablet once per day in 28-day cycles, with dose escalation done in a traditional 3 + 3 design to establish safety and determine the maximum tolerated dose. In initial cohorts, patients took umbralisib in a fasting state at a starting dose of 50 mg, increasing to 100, 200, 400, 800, 1200, and 1800 mg until the maximum tolerated dose was reached, or the maximal dose cohort was accrued without a dose-limiting toxicity. Subsequent cohorts self-administered a micronised formulation of umbralisib tablet in a fed state at an initial dose of 200 mg, increased in increments to 400, 800, 1200, and 1800 mg until the maximum tolerated dose or the maximal dose level was accrued. In August, 2014, all patients still on study were transitioned to 800 mg of the micronised formulation and dosing of the initial formulation was discontinued. The primary endpoints of the study were investigator-assessed safety in all treated patients (the safety population), the maximum tolerated dose, and the pharmacokinetics of umbralisib. Secondary endpoints included preliminary assessments of anti-cancer activity (objective responses and duration of response). Follow-up stopped for a patient once they discontinued therapy. This study has been completed and is registered with ClinicalTrials.gov, number NCT01767766.Findings: Between Jan 17, 2013, and Jan 14, 2016, we enrolled and treated 90 patients with umbralisib. The median duration of treatment and follow-up was 4·7 cycles (IQR 2·0-14·0) or 133 days (IQR 55-335). The most common treatment-emergent adverse events irrespective of causality were diarrhoea (in 39 [43%] of 90 patients), nausea (38 [42%]), and fatigue (28 [31%]). The most common grade 3 or 4 adverse events were neutropenia (in 12 [13%] patients), anaemia (eight [9%]) and thrombocytopenia (six [7%]). Serious adverse events considered at least possibly related to umbralisib occurred in seven patients: pneumonia in three (3%) patients, lung infection in one (1%), febrile neutropenia in one (1%), and colitis in two (2%), one of whom also had febrile neutropenia. The maximum tolerated dose was 1200 mg of the micronised formulation, with 800 mg of this formulation selected as the recommended phase 2 dose. Both cases of colitis occurred at above the recommended phase 2 dose. 33 (37%) of the 90 patients enrolled had an objective response to treatment with umbralisib.Interpretation: Umbralisib was well tolerated and showed preliminary signs of activity in patients with relapsed or refractory haematological malignancies. The safety profile of umbralisib in this phase 1 study was distinct from that of other PI3Kδ inhibitors, with fewer occurrences of autoimmune-like toxicities such as colitis. These findings warrant further evaluation of this agent in this setting.Funding: TG Therapeutics. [ABSTRACT FROM AUTHOR]

Background: Rovalpituzumab tesirine is a first-in-class antibody-drug conjugate directed against delta-like protein 3 (DLL3), a novel target identified in tumour-initiating cells and expressed in more than 80% of patients with small-cell lung cancer. We aimed to assess the safety and activity of rovalpituzumab tesirine in patients who progressed after one or more previous regimen.Methods: We conducted a phase 1 open-label study at ten cancer centres in the USA. Eligible patients were aged 18 years or older and had histologically or cytologically confirmed small-cell lung cancer or large-cell neuroendocrine tumours with progressive measurable disease (according to Response Evaluation Criteria in Solid Tumors [RECIST], version 1.1) previously treated with one or two chemotherapeutic regimens, including a platinum-based regimen. We assigned patients to dose-escalation or expansion cohorts, ranging from 0·05 mg/kg to 0·8 mg/kg rovalpituzumab tesirine intravenously every 3 weeks or every 6 weeks, followed by investigation of the dose schedules 0·3 mg/kg and 0·4 mg/kg every 6 weeks and 0·2 mg/kg every 3 weeks. Primary objectives were to assess the safety of rovalpituzumab tesirine, including the maximum tolerated dose and dose-limiting toxic effects. The primary activity endpoint was objective response by intention-to-treat analysis. This study is registered with ClinicalTrials.gov, number NCT01901653. The study is closed to enrolment; this report focuses on the cohort with small-cell lung cancer.Findings: Between July 22, 2013, and Aug 10, 2015, 82 patients were enrolled, including 74 patients with small-cell lung cancer and eight with large-cell neuroendocrine carcinoma, all of whom received at least one dose of rovalpituzumab tesirine. Dose-limiting toxic effects of rovalpituzumab tesirine occurred at a dose of 0·8 mg/kg every 3 weeks, including grade 4 thrombocytopenia (in two of two patients at that dose level) and grade 4 liver function test abnormalities (in one patient). The most frequent grade 3 or worse treatment-related adverse events in 74 patients with small-cell lung cancer were thrombocytopenia (eight [11%]), pleural effusion (six [8%]), and increased lipase (five [7%]). Drug-related serious adverse events occurred in 28 (38%) of 74 patients. The maximum tolerated dose of rovalpituzumab tesirine was 0·4 mg/kg every 3 weeks; the recommended phase 2 dose and schedule is 0·3 mg/kg every 6 weeks. At active doses of rovalpituzumab tesirine (0·2 mg/kg or 0·4 mg/kg every 3 weeks or 0·3 mg/kg or 0·4 mg/kg every 6 weeks), 11 (18%) of 60 assessable patients had a confirmed objective response. 11 (18%) of 60 assessable patients had a confirmed objective response, including ten (38%) of 26 patients confirmed to have high DLL3 expression (expression in 50% or more of tumour cells).Interpretation: Rovalpituzumab tesirine shows encouraging single-agent antitumour activity with a manageable safety profile. Further development of rovalpituzumab tesirine in DLL3-expressing malignant diseases is warranted.Funding: Stemcentrx Inc. [ABSTRACT FROM AUTHOR]