Phase I trial of olaparib in combination with cisplatin for the treatment of patients with advanced breast, ovarian and other solid tumors

BACKGROUND

To establish the maximum tolerated dose, determine safety/tolerability and evaluate the pharmacokinetics and preliminary efficacy of olaparib in combination with cisplatin in patients with advanced solid tumors.

PATIENTS AND METHODS

Patients aged ≥ 18 years with advanced solid tumors, who had progressed on standard treatment, were assigned to a treatment cohort and received oral olaparib [50-200 mg twice daily (bid); 21-day cycle] continuously or intermittently (days 1-5 or 1-10) in combination with cisplatin (60-75 mg/m(2) intravenously) on day 1 of each cycle.

RESULTS

Dose-limiting toxicities (DLTs) of grade 3 neutropenia (cisplatin 75 mg/m(2) with continuous olaparib 100 mg bid or 200 mg bid; n = 1 each) and grade 3 lipase elevation (cisplatin 75 mg/m(2) with olaparib 100 mg bid days 1-10 or 50 mg bid days 1-5; n = 1 each) were reported. Olaparib and cisplatin doses were subsequently reduced to 50 mg bid days 1-5 and 60 mg/m(2), respectively; no DLTs were reported for patients receiving this regimen. The most frequent grade ≥ 3 adverse events were neutropenia (16.7%), anemia (9.3%) and leucopenia (9.3%). Thirty patients (55.6%) received colony-stimulating factors for hematologic support. The overall objective response rate was 41% for patients with measurable disease, and 43% and 71% among patients with a BRCA1/2 mutation who had ovarian and breast cancer, respectively.

CONCLUSIONS

Olaparib in combination with cisplatin 75 mg/m(2) was not considered tolerable; intermittent olaparib (50 mg bid, days 1-5) with cisplatin 60 mg/m(2) improved tolerability. Promising antitumor activity in patients with germline BRCA1/2 mutations was observed and warrants further investigation.

Plasma pharmacokinetics and cerebrospinal fluid penetration of thioguanine in children with acute lymphoblastic leukemia: a collaborative Pediatric Oncology Branch, NCI, and Children's Cancer Group study

PURPOSE

In preclinical studies, thioguanine (TG) has been shown to be more potent than the standard acute lymphoblastic leukemia (ALL) maintenance agent, mercaptopurine (MP), suggesting that TG may be more efficacious than MP in the treatment of childhood ALL. As part of a pilot trial in which TG was used in place of MP, we studied the plasma pharmacokinetics of oral TG and measured steady-state plasma and CSF TG concentrations during a continuous intravenous infusion (CIVI) in children with newly diagnosed standard-risk ALL.

METHODS

Nine plasma samples were collected after each patient's first 60 mg/m2 oral TG dose during maintenance. CIVI TG (20 mg/m2/h over 24 h) was administered during the consolidation phase of therapy, and simultaneous plasma and CSF samples were collected near the end of the infusion. TG was measured by reverse-phase HPLC with ultraviolet detection. Erythrocyte TG nucleotide (TGN) concentrations were measured 7 days after a course of CIVI TG and prior to the start of each maintenance cycle.

RESULTS

After oral TG (n = 35), the mean (+/- SD) peak plasma concentration was 0.46 +/- 0.68 microM and the AUC ranged from 0.18 to 9.5 microM.h (mean 1.5 microM.h). Mean steady-state plasma and CSF TG concentrations during CIVI (n = 33) were 2.7 and 0.5 microM, respectively. The mean (+/- SD) TG clearance was 935 +/- 463 ml/min per m2. Plasma TG concentrations did not correlate with erythrocyte TGN concentrations after oral or CIVI TG. The 8-OH-TG metabolite was detected in plasma and CSF.

CONCLUSIONS

TG concentrations that are cytotoxic to human leukemia cell lines can be achieved in plasma after a 60 mg/m2 oral dose of TG and in plasma and CSF during CIVI of TG.