A Phase I Study of an MPS1 Inhibitor (BAY 1217389) in Combination with Paclitaxel Using a Novel Randomized Continual Reassessment Method for Dose Escalation

PURPOSE

Monopolar spindle 1 (MPS1) kinase inhibitor, BAY 1217389 (BAY) synergizes with paclitaxel. This phase I study assessed the combination of BAY with paclitaxel using a novel randomized continuous reassessment method (rCRM) to improve dose determination.

PATIENTS AND METHODS

Patients with solid tumors were randomized to receive oral BAY (twice daily 2-days-on/5-days-off) with weekly paclitaxel (90 mg/m²) or paclitaxel monotherapy in cycle 1. Dose escalation was guided by CRM modeling. Primary objectives were to assess safety, establish the MTD of BAY, and to evaluate the pharmacokinetic profiles for both compounds. Simulations were performed to determine the contribution of the rCRM for dose determination.

RESULTS

In total, 75 patients were enrolled. The main dose-limiting toxicities were hematologic toxicities (55.6%). The MTD of BAY was established at 64 mg twice daily with paclitaxel. Inclusion of a control arm enabled the definitive attribution of grade ≥3 neutropenia to higher BAY exposure [AUC_0-12 (P< 0.001)]. After determining the MTD, we included 19 patients with breast cancer at this dose for dose expansion. Other common toxicities were nausea (45.3%), fatigue (41.3%), and diarrhea (40.0%). Overall confirmed responses were seen in 31.6% of evaluable patients. Simulations showed that rCRM outperforms traditional designs in determining the true MTD.

CONCLUSIONS

The combination of BAY with paclitaxel was associated with considerable toxicity without a therapeutic window. However, the use of the rCRM design enabled us to determine the exposure-toxicity relation for BAY. Therefore, we propose that the rCRM could improve dose determination in phase I trials that combine agents with overlapping toxicities.

A phase l study of three different dosing schedules of the oral aurora kinase inhibitor MSC1992371A in patients with solid tumors

Aurora kinase inhibitors (AKIs) are a class of antimitotic, small-molecule anticancer agents. MSC1992371A is an AKI being evaluated for the treatment of patients with solid tumors. This phase I, open-label, dose-escalation study determined the maximum tolerated dose (MTD) of MSC1992371A in different dosing schedules in patients with locally advanced or metastatic solid tumors. MSC1992371A was administered on days 1 and 8 (schedule 1) or on days 1, 2, and 3 (schedule 2) of a 21-day cycle. The study was expanded with a third schedule (study drug on days 1-3 and 8-10). Adverse events were monitored throughout the study. Antitumor efficacy, drug pharmacokinetics, and pharmacodynamics were evaluated. Ninety-two patients were enrolled. MSC1992371A was dosed over eight levels in schedules 1 and 2, and the MTD was determined as 74 mg/m(2) per cycle for both schedules and as 60 mg/m(2) in schedule 3, albeit only in three patients due to discontinuation of the study. Overall, the most common grade 3 or 4 treatment-emergent adverse events were neutropenia, febrile neutropenia, thrombocytopenia, anemia, and fatigue. The most frequent dose-limiting toxicity over all schedules was neutropenia. MSC1992371A plasma concentrations tended to increase with increasing dose levels. Although no complete or partial responses were seen, stable disease ≥3 months was observed in 11 patients. Analysis for markers of target modulation and pharmacodynamics effects was unsuccessful. MSC1992371A was generally well tolerated in patients, with mainly transient hematologic toxicities apparent at an MTD of 60-74 mg/m(2)/21-day cycle, independent of dosing frequency.

Phase I/II multicenter study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of AZD4877 in patients with refractory acute myeloid leukemia

Eg5 (kinesin spindle protein) is a microtubule motor protein, essential for centrosome separation during mitosis. This Phase I/II, open-label, multicenter, two-part study investigated AZD4877, a potent Eg5 inhibitor, in patients with acute myeloid leukemia. Primary objectives were to determine the maximum tolerated dose (MTD) (part A), assess efficacy (part B) and determine the pharmacokinetic profile (parts A and B). Secondary objectives included assessment of safety and tolerability. AZD4877 was administered at a range of doses (2, 4, 7, 10, 13, 16 and 18 mg/day) as a 1-hour intravenous infusion on three consecutive days of a continuous 2-week schedule. The MTD in part A was defined as 16 mg/day based on dose-limiting stomatitis at 16 and 18 mg/day, hyperbilirubinemia at 16 mg/day and palmar-plantar erythrodysesthesia syndrome at 18 mg/day. Systemic exposure to AZD4877 generally increased with increasing dose whereas half-life was not dose dependent. No evaluable patients experienced a complete remission (CR) or CR with incomplete blood count recovery (CRi), demonstrating no evidence of AZD4877 efficacy in this population. Evidence of monoasters in all but the 4 mg/day dose group provided proof of mechanism for AZD4877. This study was terminated due to lack of efficacy. (ClinicalTrials.gov identifier NCT00486265).

A phase II study of intravenous (IV) wild-type reovirus (Reolysin) in the treatment of patients with bone and soft tissue sarcomas metastatic to the lung

10524

Background: Reolysin is a Dearing strain, naturally occurring, ubiquitous human reovirus. The PKR (double stranded RNA-activated protein kinase) is inhibited and therefore the virus replicates specifically in transformed cells possessing an activated Ras pathway producing lysis. In vitro and in vivo studies with Reolysin in sarcoma cell lines revealed significant antitumor activity. Methods: This phase II open-label, single agent study was designed to characterize the efficacy and safety of Reolysin given IV every 28 days in patients (pts) with bone or soft tissue sarcoma with lung metastasis using a Simon two-stage design. 38 pts were accrued to the first stage. If 1 or more pts experience clinical benefit (prolonged SD > 6 months, partial or complete response) up to 52 pts could be accrued. The agent will be considered active if 3 or more responses or prolonged SD are observed. Results: Since July 2007, 43 pts age 19–76 (median 49) were enrolled (20 female) and received a total of 141 cycles (range 1–18). All pts had performance status 1 (29 pts) or 0 (14 pts). 38 pts received prior chemotherapy, radiotherapy, biological agents or combinations for their metastatic disease, 15 pts received more than 3 chemotherapy regimens. The sarcoma subtypes included: synovial sarcoma (13 pts), osteosarcoma (7 pts), leiomyosarcoma (7 pts), MFH (5 pts), Ewing/PNET (1 pt), chordoma (1 pt), others (9 pts). Side effects were mild to moderate (grade 1–2) and included constitutional symptoms fever, chills, fatigue. Two pts experienced respiratory side effects (cough and dyspnea) and 2 pts had diarrhea. Hematological side effects included grade 2–3 neutropenia (6 pts) and grade 2 thrombocytopenia (2 pts). One patient experienced grade 2 AST elevation. 33 pts are evaluable for response to date: 14 pts (42%) had SD for 2+ months including 5 pts having SD for more than 6 months. Conclusions: Utilization of single agent reovirus for treatment of sarcoma is a novel and unique therapeutic approach to date. Reolysin is well tolerated and shows promise for the treatment of metastatic sarcoma. Primary efficacy goals have been met. Accrual is ongoing to a total of 52 pts.

[Table: see text]

A phase I study of a CanAg-targeted immunoconjugate, huC242-DM4, in patients with Can Ag-expressing solid tumors

3062

Background: HuC242-DM4 is a novel, targeted anti-cancer agent in development for the treatment of CanAg-expressing tumors such as carcinomas of the colon and pancreas. The compound is formed by the conjugation of the potent cytotoxic maytansinoid drug, DM4, to the humanized monoclonal antibody, huC242. This agent was highly active across a broad spectrum of CanAg-expressing human tumor xenograft models. Methods: Patients were enrolled with metastatic or inoperable colorectal, pancreatic, and other CanAg-expressing tumors who have failed standard therapy (about 95% of pts. had received = 4 prior chemotherapy regimens). Results: Thirty patients were treated with huC242-DM4, receiving a single intravenous (IV) infusion once every three weeks. Cohorts of 3 patients initially were enrolled on each dose level. Patients have received huC242-DM4 at 18, 36, 60, 90, 126, 168, 223, and 297 mg/m2. To date, dose limiting toxicity (DLT) was experienced by two of six patients treated at the 223 mg/m2 dose level during their second cycle of treatment. The patients experienced decreased visual acuity, corneal deposits and keratitis. Both patients were subsequently treated with lubricating eye drops. At present, these adverse events have markedly improved in one patient, while the other patient has completely returned to baseline. Of 10 patients treated at the168 mg/m2 dose level (including two patients who were dose reduced to 168 mg/m2), seven patients have received at least two cycles of treatment. One patient had grade 3 diarrhea and dehydration during his second cycle at 168 mg/m2. The latter improved with intravenous fluids. Preliminary pharmacokinetic data reveal a half-life of huC242-DM4 of about 5 days in patients with low plasma CanAg levels. In patients with high plasma CanAg levels (>900 units/mL), clearance of huC242-DM4 is increased. There has been no clinically significant myelosuppression and no formation of antibody to humanized antibody (HAHA) or drug (HADA). One patient had a 36% decline in CEA (not associated with tumor shrinkage). Conclusions: HuC242-DM4 was well tolerated at the 168 mg/m2 dose level. The MTD is not yet defined and approaches to prevent /ameliorate ocular toxicity are planned.

No significant financial relationships to disclose.

Oblimersen can be administered by subcutaneous (SC) and brief intravenous (IV) infusion: Clinical pharmacokinetics and pharmacodynamics (PK/PD) in patients with advanced cancer

14083

Background: Oblimersen (OBL) is a phosphorothioate oligodeoxynucleotide that decreases Bcl-2 protein levels. OBL has been administered by continuous intravenous infusion (CIVI) in most clinical studies. However, recent preclinical data suggest that equivalent or superior antitumor efficacy can be achieved with intermittent administration. We conducted a dose-ranging PK/PD study of OBL given by bolus SC injection and brief IV infusion to evaluate the feasibility of intermittent dosing. Methods: In this within-subject dose-escalation study, OBL was administered subcutaneously (SC) at doses of 75, 150 and 225 mg. In part II of the study, OBL was administered by 2-hr IV infusion beginning at 150 mg on day 1, by single-dose SC injection on day 8, and 2-hr IV daily x 5 consecutive days. Pharmacokinetics were assessed by non-compartmental analysis. Pharmacodynamic measurements of Bcl-2 levels in peripheral blood mononuclear (PBM) cells were made using Western blot analysis. Results: OBL absorption after SC administration was rapid with a Tmax of ∼2 hours. Mean Cmax values were 0.76, 1.70 and 3.10 μg/ml for the 75, 150 and 225 mg SC doses, respectively. Mean AUC0- inf values were 7.78, 15.36 and 25.57 hr*μg/mL. Plots of dose-normalized Cmax and AUC vs. dose showed slopes close to zero, indicating approximate dose proportionality. AUC0–24 exposure with the 225 mg SC dose was similar to previously established 24-hr steady-state AUCs after 3 mg/kg CIVI. SC injection was associated with an inflammatory erythematous grade 1 rash at the injection site that resolved within 7 days. The 150 mg 2-hr IV infusion x 1 or daily x 5 has been well-tolerated. Conclusions: OBL exposure from a single SC injection is similar to a 24-hr 3 mg/kg CIVI, and the 2-hr IV infusion is currently being evaluated. Both schedules appear to be well- tolerated, may reduce requirements for CIVI, and could be incorporated into intermittent dosing regimens.

No significant financial relationships to disclose.