Evorpacept alone and in combination with pembrolizumab or trastuzumab in patients with advanced solid tumours (ASPEN-01): a first-in-human, open-label, multicentre, phase 1 dose-escalation and dose-expansion study.

BACKGROUND: Both innate and adaptive immune responses are important components of anticancer immunity. The CD47-SIRPα interaction could represent an important pathway used by tumour cells to evade immune surveillance. We aimed to evaluate the safety, pharmacokinetics, pharmacodynamics, and anticancer activity of evorpacept (also known as ALX148), a high-affinity CD47-blocking protein with an inactive IgG Fc region in patients with solid tumours. METHODS: We did a first-in-human, open-label, multicentre, phase 1 dose-escalation and dose-expansion study at nine hospitals and one clinic in the USA and Korea. Eligible patients for the dose-escalation and safety lead-in phases were aged 18 years or older with histological or cytological diagnosis of advanced or metastatic solid tumours with no available standard therapy, measurable or unmeasurable disease according to the Response Evaluation Criteria in Solid Tumors version 1.1, and an Eastern Cooperative Oncology Group performance status score of 0 or 1. In the dose-escalation phase, which used a 3 + 3 design, patients received intravenous evorpacept at either 0·3, 1, 3, or 10 mg/kg once per week in 21-day cycles, or 30 mg/kg once every other week in 28-day cycles. In the safety lead-in phase, patients were given the maximum tolerable dose of evorpacept from the dose-escalation phase plus either intravenous pembrolizumab (200 mg administered once every 3 weeks) or intravenous trastuzumab (8 mg/kg loading dose followed by 6 mg/kg once every 3 weeks). In the dose-expansion phase, additional patients aged 18 years or older with second-line or later-line advanced malignancies were enrolled into three parallel cohorts: those with head and neck squamous cell carcinoma (HNSCC) and those with non-small-cell lung cancer (NSCLC) were given the maximum tolerated dose of evorpacept plus intravenous pembrolizumab (200 mg administered once every 3 weeks), and patients with HER2-positive gastric or gastroesophageal junction cancer were given the maximum tolerated dose of evorpacept plus intravenous trastuzumab (8 mg/kg loading dose followed by 6 mg/kg once every 3 weeks) until disease progression, voluntary withdrawal from the study, or unacceptable toxicity. The primary endpoint was the maximum tolerated dose of evorpacept administered as a single agent and in combination with pembrolizumab or trastuzumab, measured by the occurrence of dose-limiting toxicities during the first cycle, and was assessed in all patients who had received at least one dose of evorpacept. Secondary outcomes included the safety, tolerability, and antitumour activity of evorpacept, alone or in combination with pembrolizumab or trastuzumab. The primary outcome, safety, and tolerability were assessed in all patients who had received at least one dose of evorpacept, and antitumour activity was assessed in those who recieved at least one dose of study treatment and underwent at least one post-baseline tumor assessment. This trial is registered with ClinicalTrials.gov, NCT03013218. FINDINGS: Between March 6, 2017, and Feb 21, 2019, 110 patients received single-agent evorpacept (n=28), evorpacept plus pembrolizumab (n=52), or evorpacept plus trastuzumab (n=30), and were included in the safety analysis. Median follow-up was 29·1 months (95% CI not calculable [NC]-NC) in the single-agent cohort, 27·0 months (25·1-28·8) in the evorpacept plus pembrolizumab cohort, and 32·7 months (27·0-32·7) in the evorpacept plus trastuzumab cohort. Two (7%) dose-limiting toxicities in the first cycle were reported in patients who received single-agent evorpacept; neutropenia with an associated infection in one patient with gastroesophageal junction cancer who received 3 mg/kg once per week, and thrombocytopenia with associated bleeding in one patient with pancreatic cancer who received 30 mg/kg once every other week. No maximum tolerated dose was reached; the maximum administered doses were 10 mg/kg once per week or 30 mg/kg once every other week. The 10 mg/kg once per week dose was used in the expansion cohorts in combination with pembrolizumab or trastuzumab. The most common grade 3 or worse treatment-related adverse events were thrombocytopenia with single-agent evorpacept (two [7%] patients) and evorpacept plus pembrolizumab (two [4%]), and thrombocytopenia (two [7%]) and neutropenia (two [7%]) with evorpacept plus trastuzumab. In patients who received single-agent evorpacept, four treatment-related serious adverse events were reported. Five serious treatment-related adverse events related to evorpacept plus pembrolizumab were reported, and one serious adverse event related to evorpacept plus trastuzumab was reported. In response-evaluable patients in the dose-escalation phase (n=15) receiving single-agent evorpacept once per week, four (27%) had a best overall response of stable disease (two received 0·3 mg/kg, one received 3 mg/kg, and one received 10 mg/kg); in the 11 patients who received single-agent evorpacept at the highest dose of 30 mg/kg once every other week, two (18%) had stable disease. In the dose-expansion cohort, overall responses were recorded in four (20·0%; 95% CI 5·7-43·7) of 20 patients with HNSCC who received evorpacept plus pembrolizumab, in one (5·0%; 0·1-24·9) of 20 patients with NSCLC who received evorpacept plus pembrolizumab, and in four (21·1%; 6·1-45·6) of 19 patients with gastric or gastroesophageal junction cancer who received evorpacept plus trastuzumab. INTERPRETATION: The safety findings support the use of evorpacept in combination with pembrolizumab or trastuzumab for patients with advanced solid tumours. Preliminary antitumour activity results support future investigation of evorpacept combined with pembrolizumab or trastuzumab in patients with HNSCC, gastric or gastroesophageal junction cancer, and NSCLC. FUNDING: ALX Oncology.

Phase I, dose-escalation trial of the oral cyclin-dependent kinase 4/6 inhibitor PD 0332991, administered using a 21-day schedule in patients with advanced cancer.

PURPOSE: To identify the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of the first-in-class, oral CDK4/6 inhibitor PD 0332991 administered once daily for 21 of 28 days (3/1 schedule) in patients with retinoblastoma protein (Rb)-positive advanced solid tumors and to describe pharmacokinetic-pharmacodynamic relationships relative to drug effects. EXPERIMENTAL DESIGN: This open-label phase I study (NCT00141297) enrolled patients who received PD 0332991 orally in six dose-escalation cohorts in a standard 3 + 3 design. RESULTS: Forty-one patients were enrolled. DLTs were observed in five patients (12%) overall; at the 75, 125, and 150 mg once daily dose levels. The MTD and recommended phase II dose of PD 0332991 was 125 mg once daily. Neutropenia was the only dose-limiting effect. After cycle 1, grade 3 neutropenia, anemia, and leukopenia occurred in five (12%), three (7%), and one (2%) patient(s), respectively. The most common non-hematologic adverse events included fatigue, nausea, and diarrhea. Thirty-seven patients were evaluable for tumor response; 10 (27%) had stable disease for ≥4 cycles of whom six derived prolonged benefit (≥10 cycles). PD 0332991 was slowly absorbed (median T(max), 5.5 hours), and slowly eliminated (mean half-life was 25.9 hours) with a large volume of distribution (mean, 2,793 L). The area under the concentration-time curve increased linearly with dose. Using an E(max) model, neutropenia was shown to be proportional to exposure. CONCLUSIONS: PD 0332991 warrants phase II testing at 125 mg once daily, at which dose neutropenia was the sole significant toxicity.

Early phase II trial of oral vorinostat in relapsed or refractory breast, colorectal, or non-small cell lung cancer.

Vorinostat (Zolinza) is a histone deacetylase inhibitor that has demonstrated activity in patients with advanced solid tumors in phase I trials. A multicenter, open-label phase II trial of oral vorinostat 200, 300 or 400 mg bid for 14 days followed by a 7-day rest until disease progression or intolerable toxicity was conducted. Patients with measurable, relapsed or refractory breast or non-small cell lung cancer who had received > or = 1 prior therapy or colorectal cancer who had received > or = 2 prior therapies were eligible. The response rate, safety and tolerability were evaluated. Sixteen patients (median age, 62 years; median 5.5 prior therapies) were enrolled. Six patients received 400 mg bid, six received 300 mg bid and four received 200 mg bid (14 days/3 weeks). Dose-limiting toxicities (DLTs) at the 400 or 300 mg bid levels were anorexia, asthenia, nausea, thrombocytopenia, vomiting, and weight loss. No DLTs were observed at the 200 mg bid level. Disease stabilization was observed in eight patients, but there were no confirmed responses. The median TTP was 33.5 days. Eleven patients discontinued due to clinical adverse experiences (AEs). The most common drug-related AEs were anorexia (81%), fatigue (62%), nausea (62%), diarrhea (56%), vomiting (56%), thrombocytopenia (50%) and weight loss (50%). Drug-related AEs > or = grade 3 included thrombocytopenia (50%), anemia (12%), asthenia (12%) and nausea (12%). Vorinostat in a daily oral schedule for 14 days/3 weeks was tolerable at 200 mg bid only, and no responses were observed in this study. Most patients, however, had limited drug exposure which did not allow a reliable efficacy analysis.

Phase 1 study of the histone deacetylase inhibitor vorinostat (suberoylanilide hydroxamic acid [SAHA]) in patients with advanced leukemias and myelodysplastic syndromes.

Vorinostat (suberoylanilide hydroxamic acid, SAHA) is a histone deacetylase inhibitor active clinically in cutaneous T-cell lymphoma and preclinically in leukemia. A phase 1 study was conducted to evaluate the safety and activity of oral vorinostat 100 to 300 mg twice or thrice daily for 14 days followed by 1-week rest. Patients with relapsed or refractory leukemias or myelodysplastic syndromes (MDS) and untreated patients who were not candidates for chemotherapy were eligible. Of 41 patients, 31 had acute myeloid leukemia (AML), 4 chronic lymphocytic leukemia, 3 MDS, 2 acute lymphoblastic leukemia, and 1 chronic myelocytic leukemia. The maximum tolerated dose (MTD) was 200 mg twice daily or 250 mg thrice daily. Dose-limiting toxicities were fatigue, nausea, vomiting, and diarrhea. Common drug-related adverse experiences were diarrhea, nausea, fatigue, and anorexia and were mild/moderate in severity. Grade 3/4 drug-related adverse experiences included fatigue (27%), thrombocytopenia (12%), and diarrhea (10%). There were no drug-related deaths; 7 patients had hematologic improvement response, including 2 complete responses and 2 complete responses with incomplete blood count recovery (all with AML treated at/below MTD). Increased histone acetylation was observed at all doses. Antioxidant gene expression may confer vorinostat resistance. Further evaluation of vorinostat in AML/MDS is warranted.

Female donors contribute to a selective graft-versus-leukemia effect in male recipients of HLA-matched, related hematopoietic stem cell transplants.

Male recipients of transplants from female (F-->M) hematopoietic stem cell donors represent a special group in whom donor T cells that are specific for recipient minor histocompatibility antigens encoded by Y-chromosome genes may contribute to a graft-versus-leukemia (GVL) effect and to graft-versus-host disease (GVHD). We examined the contribution of donor/patient sex to the risk for relapse and GVHD in 3238 patients who underwent HLA-identical sibling hematopoietic stem cell transplantation (HSCT) for hematopoietic malignancies at a single institution. Compared with other sex combinations, male recipients of female transplants had the lowest risk for relapse and the greatest odds for GVHD. Remarkably, after controlling for GVHD as a time-dependent covariate, F-->M HSCT still exhibited a lower risk for relapse than other sex combinations, demonstrating a selective GVL effect distinct from that contributed by GVHD. A reduction in relapse after F-->M HSCT was observed in patients with chronic myelogenous leukemia (CML), acute myelogenous leukemia (AML), and acute lymphoblastic leukemia (ALL). Taken together, these data suggest that minor H antigens encoded or regulated by genes on the Y chromosome contribute to a selective GVL effect against myeloid and lymphoid leukemias after F-->M HSCT.