Tazemetostat, an EZH2 inhibitor, in relapsed or refractory B-cell non-Hodgkin lymphoma and advanced solid tumours: a first-in-human, open-label, phase 1 study.

BACKGROUND: Activating enhancer of zeste homolog 2 (EZH2) mutations or aberrations of the switch/sucrose non-fermentable (SWI/SNF) complex (eg, mutations or deletions of the subunits INI1 or SMARCA4) can lead to aberrant histone methylation, oncogenic transformation, and a proliferative dependency on EZH2 activity. In this first-in-human study, we aimed to investigate the safety, clinical activity, pharmacokinetics, and pharmacodynamics of tazemetostat, a first-in-class selective inhibitor of EZH2. METHODS: We did an open-label, multicentre, dose-escalation, phase 1 study using a 3 + 3 design with planned cohort expansion at the two highest doses below the maximally tolerated dose. The study was done at two centres in France: Institut Gustave Roussy (Villejuif, Val de Marne) and Institut Bergonié (Bordeaux, Gironde). Eligible patients had relapsed or refractory B-cell non-Hodgkin lymphoma or an advanced solid tumour and were older than 18 years, with Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate end-organ function. Tazemetostat was administered orally from 100 mg twice daily to 1600 mg twice daily in 28-day cycles. The primary endpoint was to establish the maximum tolerated dose or recommended phase 2 dose of tazemetostat, as determined by dose-limiting toxicities, laboratory values, and other safety or pharmacokinetic measures in cycle one according to local investigator assessment. Safety was assessed in patients who received at least one dose of tazemetostat; antitumour activity was assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01897571. The phase 1 part of the study is complete, and phase 2 is ongoing. FINDINGS: Between June 13, 2013, and Sept 21, 2016, 64 patients (21 with B-cell non-Hodgkin lymphoma, and 43 with advanced solid tumours) received doses of tazemetostat. The most common treatment-related adverse events, regardless of attribution, were asthenia (21 [33%] of 64 treatment-related events), anaemia (nine [14%]), anorexia (four [6%]), muscle spasms (nine [14%]), nausea (13 [20%]), and vomiting (six [9%]), usually grade 1 or 2 in severity. A single dose-limiting toxicity of grade 4 thrombocytopenia was identified at the highest dose of 1600 mg twice daily. No treatment-related deaths occurred; seven (11%) patients had non-treatment-related deaths (one at 200 mg twice daily, four at 400 mg twice daily, and two at 1600 mg twice daily). The recommended phase 2 dose was determined to be 800 mg twice daily. Durable objective responses, including complete responses, were observed in eight (38%) of 21 patients with B-cell non-Hodgkin lymphoma and two (5%) of 43 patients with solid tumours. INTERPRETATION: Tazemetostat showed a favourable safety profile and antitumour activity in patients with refractory B-cell non-Hodgkin lymphoma and advanced solid tumours, including epithelioid sarcoma. Further clinical investigation of tazemetostat monotherapy is ongoing in phase 2 studies in adults and a phase 1 study for children, which are currently enrolling patients who have B-cell non-Hodgkin lymphoma and INI1-negative or SMARCA4-negative tumours. FUNDING: Epizyme and Eisai.

A phase I study of ispinesib, a kinesin spindle protein inhibitor, administered weekly for three consecutive weeks of a 28-day cycle in patients with solid tumors.

PURPOSE: To establish the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), safety, and pharmacokinetic profile of ispinesib when administered as a 1-h intravenous infusion weekly for three consecutive weeks of a 28 day treatment period to patients with advanced solid tumors. EXPERIMENTAL DESIGN: Thirty patients were enrolled using an initial accelerated dose-escalation phase followed by a standard dose-escalation phase at doses ranging from 1-8 mg/m(2)/week. Pharmacokinetic samples, skin punch biopsies, and tumor biopsies (in patients with accessible tumor) were obtained during cycle 1 of treatment. Disease assessment was performed every two treatment cycles. RESULTS: The MTD was defined as 7 mg/m(2) administered as a 1-h infusion weekly for three consecutive weeks of a 28 day schedule. The MTD was exceeded at 8 mg/m(2) due to DLTs of grade 2 (one patient) and grade 3 neutropenia (one patient) that resulted in the inability to administer the Day 15 dose in Cycle 1. The neutrophil nadir occurred at approximately Day 8 with a 3-7 day recovery period. The most common toxicities were nausea, diarrhea, fatigue, and neutropenia. Alopecia, mucositis, and neuropathy were not observed. Stable disease was reported as the best response to treatment in nine patients. CONCLUSION: The recommended dose of ispinesib is 7 mg/m(2) over 1 h weekly for three consecutive weeks of a 28 day treatment cycle.

A first in human study of SB-743921, a kinesin spindle protein inhibitor, to determine pharmacokinetics, biologic effects and establish a recommended phase II dose.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), safety, pharmacokinetics, and pharmacodynamics of SB-743921 when administered as a 1-h infusion every 21 days to patients with advanced solid tumors or relapsed/refractory lymphoma. METHODS: Patients who failed prior standard therapy or those without any standard options were eligible. Forty-four patients were enrolled using an initial accelerated dose-escalation phase followed by a standard dose-escalation phase. An additional 20 patients were enrolled at the recommended phase II dose to obtain additional safety and pharmacokinetic data. The doses evaluated ranged from 2 to 8 mg/m(2). The pharmacokinetics of SB-743921 was evaluated at 19 time-points over 48 h following during administration during cycle 1. Toxicity was assessed by the NCI Common Terminology Criteria version 3.0. Response evaluation was performed every 6 weeks. RESULTS: The most common and consistent DLT was neutropenia. Other DLTs observed included hypophosphatemia, pulmonary emboli, SVC syndrome, transaminitis, hyponatremia, and hyperbilirubinemia. The MTD of SB-743921 as a 1-h infusion every 21 days was established as 4 mg/m(2). The maximum plasma concentration and area under the plasma concentration time curve appeared to increase proportionally to dose. One durable objective response was seen in a patient with metastatic cholangiocarcinoma who was on treatment 11 months and 6 patients had stable disease for over four cycles. CONCLUSIONS: The recommended phase II dose of SB-743921 on this specific schedule of a 1-h infusion every 3 weeks is 4 mg/m(2). The promising efficacy and lack of severe toxicities in this study warrant the continued development of SB-743921.

Phase I dose escalation and pharmacokinetic study of lapatinib in combination with trastuzumab in patients with advanced ErbB2-positive breast cancer.

PURPOSE: The combination of lapatinib and trastuzumab has been observed to have a synergistic, antiproliferative effect against ErbB2-positive breast cancer cells in vitro. This phase I study assessed the safety, clinical feasibility, optimally tolerated regimen (OTR), pharmacokinetics (PK), and preliminary clinical activity of this combination in patients with ErbB2-positive advanced breast cancer. PATIENTS AND METHODS: Cohorts of three patients with ErbB2-positive advanced breast cancer were treated with escalating doses of lapatinib (750 to 1,500 mg) administered once daily (continuous) in combination with trastuzumab (4 mg/kg loading dose then 2 mg/kg weekly) to determine the OTR. Once the OTR was determined, additional patients were enrolled to provide the PK profile of both agents alone and in combination. RESULTS: A total of 54 patients were treated: 27 in the dose-escalation group and 27 in the PK group. Overall, adverse events were mild to moderate in severity, with no drug-related grade 4 events. The most frequent drug-related grade 3 events included diarrhea (17%), fatigue (11%), and rash (6%). The OTR was 1,000 mg lapatinib with standard weekly trastuzumab. One patient had a complete response and seven patients had partial responses. The PK parameters (maximum concentration in plasma and area under the curve) of lapatinib and trastuzumab in combination were not significantly different than when either was administered alone. CONCLUSION: The OTR of the lapatinib/trastuzumab combination was lapatinib 1,000 mg per day with standard weekly trastuzumab. At these doses, the regimen was well tolerated and clinically active in this heavily pretreated ErbB2-positive breast cancer population.

Phase I and pharmacokinetic study of lapatinib in combination with capecitabine in patients with advanced solid malignancies.

PURPOSE: This phase I trial (EGF10005) assessed the safety, optimally tolerated regimen (OTR), and pharmacokinetics of lapatinib and capecitabine in combination in patients with advanced solid malignancies. PATIENTS AND METHODS: Patients with previously treated, advanced solid malignancies were eligible. Cohorts of at least three patients each received once-daily oral lapatinib (continuous) and capecitabine (twice daily for 14 days every 21 days). Doses of lapatinib and capecitabine were escalated based on dose-limiting toxicities in the first treatment cycle until the OTR was reached. Additional patients were treated at the OTR dose level to further evaluate safety and for pharmacokinetic analyses. RESULTS: Forty-five patients were treated in the study. The OTR was determined to be lapatinib 1,250 mg/d plus capecitabine 2,000 mg/m(2)/d. The majority of drug-related adverse events were grade 1 to grade 2 in severity, with few grade 3 and no grade 4 toxicities. The most common drug-related toxicities (> 15% of patients) were diarrhea, nausea, rash, palmar-plantar erythrodysesthesia, mucositis, vomiting, and stomatitis. There were four confirmed responses (one complete response and three partial responses). The pharmacokinetics (area under the curve and maximum concentration) of lapatinib, capecitabine and its metabolites, fluorouracil, and alpha-fluoro-beta-alanine, were not meaningfully altered by coadministration. CONCLUSION: Lapatinib and capecitabine administered on a 3-week schedule were well tolerated, and no pharmacokinetic interaction was observed. Clinical activity was observed in patients with previously treated, advanced solid malignancies.

Regulatory approvals of pediatric oncology drugs: previous experience and new initiatives.

PURPOSE: To review the Food and Drug Administration (FDA) experience with approvals of new drugs for pediatric oncology and to discuss new regulatory initiatives directed at pediatric oncology. METHODS: A retrospective review of FDA archival documents and the published literature. RESULTS: More than 100 drugs have been approved by the Division of Oncology Drug Products of the FDA for the treatment of malignancies. Only 15 have pediatric use information in their labeling, which is less than 50% of the drugs commonly used in the treatment of pediatric malignancies. In the past 20 years, there have been six submissions to the FDA for pediatric oncology indications. To illustrate principles of the approval process, each submission is discussed. CONCLUSION: Potential reasons for a lack of New Drug Application submissions for pediatric oncology include the small pediatric oncology market compared with the adult oncology market and perceived barriers to performing studies in children. Reasons for failure to approve pediatric indications include small numbers of patients, lack of appropriate controls, and failure to demonstrate patient benefit. Approval criteria include the use of controlled trials, prospective data collection, and disease-appropriate end points. Regulatory initiatives to promote pediatric therapeutic development and product labeling are discussed.

Phase I study of perillyl alcohol in patients with refractory malignancies.

We treated 21 patients in a dose-finding and pharmacokinetic study of the monoterpene perillyl alcohol with the drug given orally in 3 divided doses on a chronic basis. The average number of days that patients remained on study was 48 (range 11-172). Fatigue and low-grade nausea were dose limiting. Using this schedule, a starting dose of 1.6 g/m2 with escalation to 2.1 g/m2 as tolerated is recommended. Two major metabolites were detectable and the mean peak plasma concentrations were 383 microM for perillic acid and 27 microM for dihydroperillic acid. The peak plasma concentration and the metabolite half-life were 2 h and 1 h post ingestion for perillic acid, and 4 h and 2.4 h for dihydroperillic acid, respectively. Stabilization of disease was observed in one of the 16 patients evaluable for response. Many of the gastrointestinal side effects that were poorly tolerated on a chronic basis may be partly related to the soybean oil base used in the current formulation. Further development of perillyl alcohol on this schedule would be facilitated by reformulation of the capsule.