A phase I trial of AT9283 (a selective inhibitor of Aurora kinases) given for 72 hours every 21 days via intravenous infusion in children and adolescents with relapsed and refractory solid tumours.
Darren R Hargrave
Background: AT9283, is a multi-targeted inhibitor, against Aurora A and B, JAK & ABL kinases. Aurora kinases are potential therapeutic targets in paediatric solid cancers.
Methods: A phase I dose escalation study was performed using a 72 hour intravenous infusion repeated 3 weekly using a rolling 6 design for patients aged >2 to <19 years with relapsed/ refractory solid tumours.
Results: Eighteen patients treated with a median age of 10 (range 3 to 16) years. Four dose cohorts of 7, 9, 11.5 and 14.5 mg/m2/day. The diagnoses included; 5 high grade glioma, 4 rhabdoid tumours, 3 neuroblastomas, 3 sarcomas & 3 others. There has been only one dose limiting toxicity; Grade 3 febrile neutropenia at 11.5 mg/m2/day. The majority of adverse events (AEs) have been grade 1/2 & considered unrelated/ unlikely related to study drug. Two patients have experienced Grade 3 or 4 AEs considered at least possibly related to study drug: Grade 3 haemoglobin and Grade 4 neutrophils in a patient treated at 9 mg/m2/day & Grade 3 lymphopenia, neutrophils, infection with normal neutrophil count and aspartate transaminase in a patient treated at 11.5 mg/m2/day. Pharmacokinetics of AT9283 in this population are largely in keeping with those seen in adult patients at similar doses (Arkenau et al., 2011) although there may be greater variability. Pharmacodynamic evidence of aurora B inhibition, as manifested by a reduction in histone H3 phosphorylation in normal skin biopsies pre & post infusion, has been documented at all dose levels tested. Stable disease (up to 6 cycles) has been observed in 3 patients.
Conclusions: This paediatric phase I study has demonstrated AT9283 administered as a 72 hour continuous infusion can be given at a dose level of 11.5 mg/m2/day which is higher than the maximum tolerated dose observed in adult patients (9 mg/m2/day) with advanced solid tumours. Myelosuppresion is the main toxicity but the regimen is well tolerated with preliminary anticancer activity seen in heavily pre-treated paediatric patients.
A phase I/II study to evaluate the ability of decitabine and panobinostat to improve temozolomide chemosensitivity in metastatic melanoma.
Background: Epigenetic gene regulation is likely a contributing mechanism of cancer initiation and progression. Emerging evidence indicates that epigenetics may also play a key role in the development of chemoresistance in melanoma. We proposed combining the histone deacetylase inhibitor panobinostat (PT) and the demethylator decitabine (D) to overcome the development of epigenetic mediated temozolomide (TMZ) resistance in metastatic melanoma.
Methods: Eligible patients must be ≥18, stage IV melanoma, and naïve or previously treated, with good performance status (ECOG ≤ 2) and normal organ functions. Patients with previous exposure to TMZ were allowed on study. The study includes the dose escalation of D and PT followed by expansion cohorts. D (0.1mg/kg SQ, 0.2mg/kg SQ) on days 1, 3, 5, 8, 10,12, PT (10mg PO, 20mg PO, 30mg PO) Q96h starting day 8, and TMZ 150mg/m2 PO daily on days 9-13 of each 42 day cycle. TMZ was increased to 200mg/m2 in the absence of grade 2 thrombocytopenia. Primary endpoints of phase I study are to determine the toxicity, safety and maximum tolerated dose (MTD) of the D, PT and TMZ combination.
Results: To date, the phase I portion of this trial is completed. We report on the safety data for this combination. 17 patients received treatment (1st cohort: 5; 2nd cohort: 4; 3rd cohort: 4; 4th cohort: 4 ). M:F 11:6. Median age: 56 (32-77); Median ECOG PS: 1; 82% of the patients received at least one cycle (n=14). Median number of cycles given: 2 (0-6). To date, no DLTs have occurred. The MTD was not reached. The only grade (G) 4 adverse event (AE) is neutropenia on a patient in cohort 3 and it resolved within 3 days. G3 AEs included lymphopenia (n=4, 23%), anemia (n=2, 12%), leukopenia (n=2, 12%) and fatigue (n=2, 12%). Common G2 toxicities were leukopenia (n=5, 30%), neutropenia (n=4, 23%), nausea (n=4, 23%) and lymphopenia (n=3, 18%).
Conclusions: The combination of D, PT, and TMZ appears to be safe and well-tolerated. The recommended dose for the phase II study remains to be determined.
Background: A phase III trial (NCT00260832) in patients (N=485) ≥65y with newly diagnosed acute myeloid leukemia (AML) was conducted (Kantarjian, JCO; in press). Every 4 wk, patients received decitabine (DAC) 20 mg/m2 (1-h intravenous infusion, 5 successive days) or treatment choice (TC) with either supportive care or cytarabine (20 mg/m2 subcutaneous injection daily, 10 successive days). This post hoc analysis examined whether baseline (BL) renal and hepatic function and white blood cell (WBC) counts were associated with response to DAC or TC. Methods: For patients with available data, BL WBC count and markers of renal function (blood urea nitrogen [BUN], creatinine) and liver function (ALT, AST, albumin) were tabulated for patients with/without a response to DAC or TC. Response was defined as morphologic complete remission (CR), CR with incomplete blood count recovery (CRi), or partial remission (PR). Results: Nonresponders had a higher mean BL creatinine vs responders (86.78 vs 80.23 mmol/L, respectively; P=.005); with no differences in BL BUN levels. There were no other between-group differences.
Conclusions: This analysis suggests that there is no relationship between BL WBC or hepatic function and response to treatment with DAC or TC. Although there was no difference in BL BUN, higher mean creatinine levels in nonresponders may suggest a prognostic relationship but further studies are needed to clarify.
Post hoc analysis of relationship between baseline white blood cell count and survival outcome in a randomized phase III trial of decitabine in older patients with newly diagnosed acute myeloid leukemia
Background: In a large phase III trial (N=485), patients (pts) ≥65y with newly diagnosed acute myeloid leukemia (AML) received 1-h IV infusion of decitabine (DAC) 20 mg/m2 for 5 consecutive days every 4 wk or treatment choice (TC) with supportive care or cytarabine 20 mg/m2 subcutaneous injection for 10 consecutive days every 4 wk (NCT00260832; Kantarjian et al. JCO, in press). Enrolled pts had white blood cell (WBC) count <40 x109/L; baseline WBC counts were relatively low (median [range] DAC: 3.1 x109/L [0.3-127.0]; TC: 3.7 x109/L [0.5-80.9]). This post hoc analysis assessed baseline WBC count and survival outcome.
Methods: Overall survival (OS) and progression-free survival (PFS) were summarized by baseline WBC subgroups (<1, 1-5, >5 x109/L).
Results: Mature survival data (2010) were based on intent-to-treat (ITT) population (446 deaths: TC, n=227; DAC, n=219). OS was 5.0 mo for TC vs 7.7 mo for DAC (nominal P=.037). For each WBC subgroup, differences in OS for TC vs DAC were not significant (NS), but hazard ratios (HR) favored DAC for all subgroups (Table). There was a significant difference in PFS in favor of DAC for patients with baseline WBC 1–5 x109/L (P=.005; HR=0.67) and >5 x109/L (P=.027; HR=0.71). Conclusions: These data are consistent with overall results, with a trend toward improved outcome with DAC regardless of baseline WBC count in older pts with newly diagnosed AML. Further analyses are warranted.
Post hoc analysis of association between treatment response and various indicators of efficacy and safety in a randomized phase III trial of decitabine in older patients with acute myeloid leukemia.
Background: In a recent, large phase III trial (NCT00260832; Kantarjian, JCO; in press), 485 patients ≥65y with newly diagnosed acute myeloid leukemia (AML) received, every 4 wks, treatment choice (TC) of either supportive care or cytarabine (20 mg/m2 subcutaneous injection, 10 consecutive days) or decitabine (DAC) 20 mg/m2 (1-h intravenous [IV] infusion, 5 consecutive days). This post hoc analysis investigated relationships between response to treatment and indicators of efficacy and safety.
Methods: Response was defined as morphologic complete remission (CR), or CR with incomplete blood count recovery (CRi) or partial response (PR). Transfusions (red blood cell [RBC] or platelets [PLT]), IV antibiotic use, and dose modifications were tabulated for responders and nonresponders to DAC or TC during the treatment period.
Results: Fewer responders than nonresponders had dose modifications (30.4% vs 64.5%, respectively; P<.0001). Antibiotic use and transfusions were similar in both groups. Overall survival for responders was 16.1–18.5 mo vs 4.2–4.9 mo for nonresponders.
Conclusions: These data suggest that response to DAC or TC treatment predicts clinically relevant benefits, with fewer dose modifications in older patients with newly diagnosed AML. The number of transfusions and antibiotic use was impacted by the longer survival time of responders vs nonresponders. Data on the impact of early response are being analyzed.