HER2 is a transmembrane tyrosine kinase receptor that mediates cell growth, differentiation, and survival. HER2 is overexpressed in approximately 20% of breast cancers and in subsets of gastric, ...colorectal, and esophageal cancers. Both antibody and small-molecule drugs that target HER2 and block its tyrosine kinase activity are effective in treating HER2-driven cancers. In this article, we describe the preclinical properties of tucatinib, an orally available, reversible HER2-targeted small-molecule tyrosine kinase inhibitor. In both biochemical and cell signaling experiments, tucatinib inhibits HER2 kinase activity with single-digit nanomolar potency and provides exceptional selectivity for HER2 compared with the related receptor tyrosine kinase EGFR, with a >1,000-fold enhancement in potency for HER2 in cell signaling assays. Tucatinib potently inhibits signal transduction downstream of HER2 and HER3 through the MAPK and PI3K/AKT pathways and is selectively cytotoxic in HER2-amplified breast cancer cell lines
.
, tucatinib is active in multiple HER2
tumor models as a single agent and shows enhanced antitumor activity in combination with trastuzumab or docetaxel, resulting in improved rates of partial and complete tumor regression. These preclinical data, taken together with the phase-I tucatinib clinical trial results demonstrating preliminary safety and activity, establish the unique pharmacologic properties of tucatinib and underscore the rationale for investigating its utility in HER2
cancers. GRAPHICAL ABSTRACT: http://mct.aacrjournals.org/content/molcanther/19/4/976/F1.large.jpg.
Summary
Spleen tyrosine kinase (Syk) mediates B‐cell receptor signalling in normal and malignant B cells. Entospletinib is an oral, selective Syk inhibitor. Entospletinib monotherapy was evaluated in ...a multicentre, phase 2 study of patients with relapsed or refractory indolent non‐Hodgkin lymphoma or mantle cell lymphoma (MCL). Subjects received 800 mg entospletinib twice daily. Forty‐one follicular lymphoma (FL), 17 lymphoplasmacytoid lymphoma/Waldenström macroglobulinaemia (LPL/WM), 17 marginal zone lymphoma (MZL) and 39 MCL patients were evaluated. The primary endpoint was a progression‐free survival (PFS) rate (defined as not experiencing progression or death) at 16 weeks for patients with MCL and at 24 weeks for patients with FL, LPL/WM and MZL. The most common treatment‐emergent adverse events were fatigue, nausea, diarrhoea, vomiting, headache and cough. Common laboratory abnormalities were anaemia, neutropenia and thrombocytopenia; aspartate transaminase, alanine transaminase, total bilirubin and serum creatinine were all increased. PFS at 16 weeks in the MCL cohort was 63·9% 95% confidence interval (CI) 45–77·8%; PFS at 24 weeks in the FL, LPL/WM, MCL and MZL cohorts was 51·5% (95% CI 32·8–67·4%), 69·8% (95% CI 31·8–89·4%), 56·6% (95% CI 37·5–71·8%) and 46·2% (95% CI 18·5–70·2%), respectively. Entospletinib had limited single‐agent activity with manageable toxicity in these patient populations.
Autologous stem cell transplantation (ASCT) is standard of care for patients with Hodgkin lymphoma (HL) who have relapsed/refractory disease after frontline chemotherapy. Achievement of complete ...remission (CR) with pre-ASCT salvage chemotherapy predicts favorable outcomes post-ASCT. This phase 1/2 study evaluated the combination of brentuximab vedotin (BV) plus bendamustine as a first salvage regimen in relapsed/refractory HL. A total of 55 patients (28 primary refractory and 27 relapsed) were enrolled. Patients received BV (1.8 mg/kg) on day 1 and bendamustine (90 mg/m2) on days 1 and 2 of a 21-day cycle for up to 6 cycles. Patients could undergo ASCT any time after cycle 2. Following ASCT or completion of combination therapy if not proceeding to ASCT, patients could receive BV monotherapy for up to 16 cycles of total therapy. After a median of 2 cycles of combination therapy (range, 1-6), the objective response rate among 53 efficacy-evaluable patients was 92.5%, with 39 patients (73.6%) achieving CR. Forty patients underwent ASCT. Thirty-one patients (25 of whom underwent ASCT) received BV monotherapy (median, 10 cycles; range, 1-14). After a median of 20.9 months of follow-up, the estimated 2-year progression-free survival was 69.8% and 62.6% for patients who received ASCT and all patients, respectively. Thirty-one patients (56.4%) experienced infusion-related reactions (IRRs), with a majority occurring during cycle 2 of combination therapy. A protocol amendment requiring premedication reduced IRR severity. BV plus bendamustine as first salvage therapy in relapsed/refractory HL is highly active with a manageable toxicity profile. This trial was registered at www.clinicaltrials.gov as #NCT01874054.
•The outpatient BV and bendamustine regimen is highly active as first salvage therapy in relapsed/refractory HL, with manageable toxicity.•The CR rate of 73.6% exceeded those reported for standard chemotherapy regimens, and post-ASCT outcomes generally appeared excellent.
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Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers monomethyl auristatin E, an antimicrotubule agent, into CD30-expressing cells. In phase I studies, brentuximab ...vedotin demonstrated significant activity with a favorable safety profile in patients with relapsed or refractory CD30-positive lymphomas.
In this multinational, open-label, phase II study, the efficacy and safety of brentuximab vedotin were evaluated in patients with relapsed or refractory Hodgkin's lymphoma (HL) after autologous stem-cell transplantation (auto-SCT). Patients had histologically documented CD30-positive HL by central pathology review. A total of 102 patients were treated with brentuximab vedotin 1.8 mg/kg by intravenous infusion every 3 weeks. In the absence of disease progression or prohibitive toxicity, patients received a maximum of 16 cycles. The primary end point was the overall objective response rate (ORR) determined by an independent radiology review facility.
The ORR was 75% with complete remission (CR) in 34% of patients. The median progression-free survival time for all patients was 5.6 months, and the median duration of response for those in CR was 20.5 months. After a median observation time of more than 1.5 years, 31 patients were alive and free of documented progressive disease. The most common treatment-related adverse events were peripheral sensory neuropathy, nausea, fatigue, neutropenia, and diarrhea.
The ADC brentuximab vedotin was associated with manageable toxicity and induced objective responses in 75% of patients with relapsed or refractory HL after auto-SCT. Durable CRs approaching 2 years were observed, supporting study in earlier lines of therapy.
Background
Cluster of differentiation 70 (CD70) is frequently expressed in renal cell carcinoma (RCC) and has immunomodulatory properties. An antibody‐drug conjugate targeting CD70, SGN‐CD70A, was ...developed to treat patients with CD70‐positive RCC.
Methods
The objective of this phase 1, open‐label, dose‐escalation, multicenter study was to evaluate the safety and tolerability of SGN‐CD70A and establish its maximum tolerated dose in patients with CD70‐positive, metastatic RCC (mRCC). All subtypes of RCC were permitted, and no limit was set on the number of prior therapies. Safety assessments consisted of monitoring and recording all adverse events (AEs) and dose‐limiting toxicities (DLTs). Treatment response was assessed by radiographic tumor evaluation according to the Response Evaluation Criteria for Solid Tumors, version 1.1. A model‐based, modified continual‐reassessment method was used to estimate the probabilities of DLT and response.
Results
The maximum tolerated dose was determined to be 30 μg/kg, with thrombocytopenia as the DLT. The most common AEs were fatigue (67%), anemia (61%), and thrombocytopenia (56%). Of 18 enrolled patients, 1 achieved a partial response and 13 achieved stable disease, for a clinical benefit rate of 78%. Limitations of the study included the heavily pretreated nature of patients, receipt of a median of 4 prior lines of therapy (range, 1‐8 prior lines of therapy), and diminishing response potential.
Conclusions
The modest antitumor activity of SGN‐CD70A does not support its development in mRCC. However, given the high disease control rate in a heavily pretreated population and the modest toxicity profile, CD70 remains of interest because of its immunomodulatory properties.
The safety of the new drug SGN‐CD70A is examined in metastatic kidney cancer. Findings from the investigation indicate that SGN‐CD70A has a reasonable safety profile at lower dose levels and a modest effect in stabilizing tumors.
Summary
SGN‐30, a chimeric anti‐CD30 monoclonal antibody, has demonstrated potent preclinical antitumour activity in both Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL). We conducted ...an open‐label, Phase II study to determine the safety and objective response rate of SGN‐30 in 79 patients with refractory/recurrent HL (n = 38) or systemic ALCL (n = 41). Each course of SGN‐30 comprised 6 weekly intravenous infusions, followed by a 2‐week treatment‐free period. Patients had received a median of 3 (range 1–5) prior regimens of chemotherapy or systemic therapy. The initial 40 patients received 6 mg/kg weekly; the latter 39 patients received 12 mg/kg weekly. In the ALCL group, two patients achieved a complete response and five additional patients achieved a partial response, with response durations ranging from 27 to 1460+ d. No objective responses were observed in the HL group; however, 11 patients (29%) had stable disease (duration 62–242 days). Although adverse events were common, most were mild or moderate, and no specific pattern of adverse events was observed in either disease group. These results demonstrate that weekly administration of SGN‐30 is safe, with modest clinical activity in patients with ALCL.
Summary Background Inhibition of phosphatidylinositol 3-kinase (PI3K) is a promising approach to overcome resistance to endocrine therapy in breast cancer. Pictilisib is an oral inhibitor of multiple ...PI3K isoforms. The aim of this study is to establish if addition of pictilisib to fulvestrant can improve progression-free survival in oestrogen receptor-positive, endocrine-resistant breast cancer. Methods In this two-part, randomised, double-blind, placebo-controlled, phase 2 study, we recruited postmenopausal women aged 18 years or older with oestrogen receptor-positive, HER2-negative breast cancer resistant to treatment with an aromatase inhibitor in the adjuvant or metastatic setting, from 123 medical centres across 21 countries. Part 1 included patients with or without PIK3CA mutations, whereas part 2 included only patients with PIK3CA mutations. Patients were randomly allocated (1:1 in part 1 and 2:1 in part 2) via a computer-generated hierarchical randomisation algorithm to daily oral pictilisib (340 mg in part 1 and 260 mg in part 2) or placebo starting on day 15 of cycle 1, plus intramuscular fulvestrant 500 mg on day 1 and day 15 of cycle 1 and day 1 of subsequent cycles in both groups. In part 1, we stratified patients by presence or absence of PIK3CA mutation, primary or secondary aromatase inhibitor resistance, and measurable or non-measurable disease. In part 2, we stratified patients by previous aromatase inhibitor treatment for advanced or metastatic disease or relapse during or within 6 months of an aromatase inhibitor treatment in the adjuvant setting and measurable or non-measurable disease. All patients and those administering treatment and assessing outcomes were masked to treatment assignment. The primary endpoint was progression-free survival in the intention-to-treat population for both parts 1 and 2 and also separately in patients with PIK3CA -mutated tumours in part 1. Tumour assessment (physical examination and imaging scans) was investigator-assessed and done at screening and after 8 weeks, 16 weeks, 24 weeks, and 32 weeks of treatment from day 1 of cycle 1 and every 12 weeks thereafter. We assessed safety in as-treated patients who received at least one dose of study medication. This trial is registered with ClinicalTrials.gov , number NCT01437566. Findings In part 1, between Sept 27, 2011, and Jan 11, 2013, we randomly allocated 168 patients to the pictilisib (89 53%) or placebo (79 47%) group. In part 2, between March 18, 2013, and Jan 2, 2014, we randomly allocated 61 patients to the pictilisib (41 67%) or placebo (20 33%) group. In part 1, we found no difference in median progression-free survival between the pictilisib (6·6 months 95% CI 3·9–9·8) and placebo (5·1 months 3·6–7·3) group (hazard ratio HR 0·74 95% CI 0·52–1·06; p=0·096). We also found no difference when patients were analysed according to presence (pictilisib 6·5 months 95% CI 3·7–9·8 vs placebo 5·1 months 2·6–10·4; HR 0·73 95% CI 0·42–1·28; p=0·268) or absence (5·8 months 3·6–11·1 vs 3·6 months 2·8–7·3; HR 0·72 0·42–1·23; p=0·23) of PIK3CA mutation. In part 2, we also found no difference in progression-free survival between groups (5·4 months 95% CI 3·8–8·3 vs 10·0 months 3·6–13·0; HR 1·07 95% CI 0·53–2·18; p=0·84). In part 1, grade 3 or worse adverse events occurred in 54 (61%) of 89 patients in the pictilisib group and 22 (28%) of 79 in the placebo group. 19 serious adverse events related to pictilisib treatment were reported in 14 (16%) of 89 patients. Only one (1%) of 79 patients reported treatment-related serious adverse events in the placebo group. In part 2, grade 3 or worse adverse events occurred in 15 (36%) of 42 patients in the pictilisib group and seven (37%) of 19 patients in the placebo group. Four serious adverse events related to pictilisib treatment were reported in two (5%) of 42 patients. One treatment-related serious adverse event occurred in one (5%) of 19 patients in the placebo group. Interpretation Although addition of pictilisib to fulvestrant did not significantly improve progression-free survival, dosing of pictilisib was limited by toxicity, potentially limiting its efficacy. For future assessment of PI3K inhibition as an approach to overcome resistance to hormonal therapy, inhibitors with greater selectivity than that of pictilisib might be needed to improve tolerability and potentially increase efficacy. No further investigation of pictilisib in this setting is ongoing. Funding F Hoffmann-La Roche.
Purpose
Agents targeting programmed death receptor 1 (PD-1) or its ligand (PD-L1) have shown antitumor activity in the treatment of metastatic breast cancer (MBC). The aim of this study was to assess ...the activity of avelumab, a PD-L1 inhibitor, in patients with MBC.
Methods
In a phase 1 trial (JAVELIN Solid Tumor; NCT01772004), patients with MBC refractory to or progressing after standard-of-care therapy received avelumab intravenously 10 mg/kg every 2 weeks. Tumors were assessed every 6 weeks by RECIST v1.1. Adverse events (AEs) were graded by NCI-CTCAE v4.0. Membrane PD-L1 expression was assessed by immunohistochemistry (Dako PD-L1 IHC 73-10 pharmDx).
Results
A total of 168 patients with MBC, including 58 patients with triple-negative breast cancer (TNBC), were treated with avelumab for 2–50 weeks and followed for 6–15 months. Patients were heavily pretreated with a median of three prior therapies for metastatic or locally advanced disease. Grade ≥ 3 treatment-related AEs occurred in 13.7% of patients, including two treatment-related deaths. The confirmed objective response rate (ORR) was 3.0% overall (one complete response and four partial responses) and 5.2% in patients with TNBC. A trend toward a higher ORR was seen in patients with PD-L1+ versus PD-L1− tumor-associated immune cells in the overall population (16.7% vs. 1.6%) and in the TNBC subgroup (22.2% vs. 2.6%).
Conclusion
Avelumab showed an acceptable safety profile and clinical activity in a subset of patients with MBC. PD-L1 expression in tumor-associated immune cells may be associated with a higher probability of clinical response to avelumab in MBC.
Outcomes in older patients with Hodgkin lymphoma (HL) tend to be poor following conventional chemotherapy regimens. Treatment-related toxicity is significant and comorbidities often limit therapeutic ...options. This phase 2, open-label study evaluated the efficacy and safety of brentuximab vedotin, a CD30-directed antibody-drug conjugate, as frontline therapy in 27 HL patients aged ≥60 years. The objective response rate (ORR) was 92%, with 73% achieving complete remission. All patients achieved stable disease or better, and had decreased tumor volume following treatment. At the time of this analysis, the median duration of objective response for efficacy-evaluable patients (N = 26) was 9.1 months (range, 2.8 to 20.9+ months), median progression-free survival was 10.5 months (range, 2.6+ to 22.3+ months), and median overall survival had not been reached (range, 4.6+ to 24.9+ months). The observed adverse events (AEs) were generally consistent with the known safety profile of brentuximab vedotin. The most common AEs were peripheral sensory neuropathy (78%), fatigue (44%), and nausea (44%), and were ≤ grade 2 for most patients. The incidence of grade 3 peripheral neuropathy events was relatively high (30% overall), particularly among patients with the known risk factors of diabetes and/or hypothyroidism (46% vs 14% for those without). However, these risk factors were not associated with delayed time to resolution/improvement of peripheral neuropathy. Preliminary data showed no substantial age-related changes in brentuximab vedotin pharmacokinetics. Brentuximab vedotin monotherapy may provide a frontline treatment option for older patients who cannot tolerate conventional combination chemotherapy. This trial was registered at www.clinicaltrials.gov as #NCT01716806.
•Frontline brentuximab vedotin monotherapy provided a 92% ORR and was generally well tolerated in elderly HL patients.
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