Reconsenting patients with cancer on clinical trials: Does added risk influence continued participation?

e15610

Background: The general policy endorsed by multiple professional societies and cooperative groups regarding patients on cancer clinical trials states that subjects should be informed of new adverse events or significant developments during study participation and re-consented to continue on study. However, no information is known as to the effect of re-consenting on a patients’ decision to continue study participation. Our research question addresses how the severity of reported risk to other study participants will impact the subjects’ decision to continue participation in a clinical trial. Methods: We surveyed 34 patients with gastrointestinal (GI) tumors all of whom were currently enrolled in a clinical trial. The survey portrayed hypothetical adverse reactions affecting another study participant ranging from Grade 1 to Grade 5 according to the National Cancer Institutes Common Terminology Criteria for Adverse Effects v. 3.0. The survey asked about subjects’ opinions of the theoretical adverse event categorized as “would not be concerned,” “would be concerned, but would continue the study,” and “would discontinue the study.” Results: Patients willingness to continue the study was highest at Grade 1 with 97% of all participants. However, willingness to continue participation progressively declined as the severity of adverse events increased such that only 44% of participants would continue participation with a reported Grade 5 adverse event. Conclusions: Among surveyed GI cancer patients, willingness to continue participation in a clinical trial declined significantly as the severity of adverse events increased from Grade 1 to Grade 3 - 5 (p-value < 0.001. This could be due to multiple factors, including the terminal nature of the patients’ cancer, the side effects of study therapy and the patients’ response to study treatment. This data could produce a reasonable adverse event grade cut-off for re-consenting patients regarding new side effects.

No significant financial relationships to disclose.

A phase I study of an oral simulated FOLFOX with high dose capecitabine

BACKGROUND

A phase I study of high-dose capecitabine given over 2 days, along with oxaliplatin, bolus 5FU and leucovorin (LV), was designed to simulate FOLFOX6 without the need for infusional 5FU.

METHODS

Schedule A included oxaliplatin 100 mg/m(2), 5FU 400 mg/m(2), and LV 20 mg/m(2) (all given IV on days 1 and 15, 28 day cycle). Capecitabine was administered orally every 8 h x 6 doses, days 1 and 15. Schedule B excluded 5FU and LV, maintaining oxaliplatin and capecitabine. Pharmacokinetics were performed for capecitabine for 6 patients on each schedule.

RESULTS

36 patients were treated. The dose-limiting toxicities seen included nausea, dehydration, fatigue, hypotension and confusion. Minimal palmar-plantar erythrodysesthesia was seen. Myelosuppression was common, but not a dose limiting toxicity. The pharmacokinetic parameters for capecitabine were unaltered.

CONCLUSION

Using capecitabine to mimic FOLFOX6 is feasible and well tolerated with a toxicity profile that differs from standard 14-day capecitabine dosing, with less palmar-plantar erythrodysesthesia. The phase II dose for capecitabine in combination with oxaliplatin, 5FU, and LV is 1,500 mg/m(2)/dose or 2,250 mg/m(2)/dose in the absence of bolus 5FU/LV.

A multicenter phase 2 clinical trial testing a combination of oxaliplatin, bolus 5-fluorouracil, leucovorin and capecitabine in patients with metastatic colorectal cancer (MCRC)

14526

Introduction: The combination of oxaliplatin (OX) with bolus and infusional 5FU has shown high activity in MCRC. Substituting capecitabine (CAPE) for 5FU in a novel high-dose schedule designed to mimic FOLFOX-6 is a feasible and well tolerated treatment (Hegeman, ASCO, 2005, #2058). A multicenter phase 2 study of this combination was performed to evaluate efficacy in first-line treatment of MCRC. Methods: Eligible patients have ECOG PS 0–2, no grade 2 or higher neuropathy, and no prior systemic treatment for metastatic cancer. Patients are treated with OX 100 mg/m2, leucovorin (LV) 20 mg/m2 and 5FU 400 mg/m2 IV bolus followed by CAPE 1500 mg/m2 PO Q8H x 6 doses, repeated every two weeks. The primary endpoint was confirmed antitumoral response. Patients were allowed to come off study to pursue surgical resection, if feasible. Results: 36 out of a planned 45 patients have been enrolled since 6/04. Survival (OS) and time to progession (TTP) data are available for all 36 patients. Toxicity and efficacy data is available for 33 patients. The median age of enrolled patients is 65.5 years (range 42–78). 16 (44%) of patients are male. 94% of patients are ECOG PS 0 or 1. Toxicity data is presented in the table . 14/33 (42%) of patients had a grade 3/4 toxicity (see table ). The response rate was 33% (95% confidence interval [CI] 18–52%): 11 patients achieved a partial response (33%), 14 (42%) had stable disease, and 8 (24%) had progressive disease. Median overall survival was 17.1 months (M) (CI 0.7+-27.5+ M). The one-year survival rate was 67%. The median TTP/TTF was 4.1 M (CI 0.3–14.3 M). Four (11%) patients have come off of the study protocol to pursue metastatectomy. Conclusion: OX, infusional 5FU, LV and CAPE is active and well tolerated in MCRC. This regimen had fewer episodes of grade 3–4 hand-foot syndrome and mucositis than prior regimens including longer durations of capecitabine. Study supported by sanofi-aventis.

[Table: see text] [Table: see text]

Phase I study to determine tolerability and pharmacokinetics (PK) of SB-743921, a novel kinesin spindle protein (KSP) inhibitor

2000

Background: SB-743921, a potent and selective inhibitor of KSP (Ki =100 pM; >40,000-fold selectivity vs other kinesins), causes mitotic arrest, potent inhibition of tumor cell proliferation, and demonstrates activity in a broad range of human tumor xenografts. Methods: A phase I study was conducted to determine the maximum tolerated dose (MTD) and PK profile of SB-743921 when administered IV over 60 minutes every 21 (Q 21) days (d). Results: 44 patients (pts) (M/F 19/25), median age 61.5 yrs (range 32–80, with solid tumors were treated at doses of 2 (n=2), 4 (n=27), 5 (n=6), 6 (n=3), and 8 (n=6) mg/m2 (median cycles 2, range 1–10, total cycles 101). Frequent tumor types included colorectal (n=11), ovarian (n=5), NSCLC (n=5), esophageal (n=4), and pancreatic (n=4). Dose-limiting toxicities (DLTs) at 8 mg/m2 consisted of (max CTC grade/pt) prolonged grade (gr) 4 neutropenia (n=2), gr 3 elevated ALT/AST (n=1), and gr 3 elevated bilirubin (n=1). DLTs at 6 mg/m2 were gr 3 hyponatremia (n=1) and prolonged gr 4 neutropenia (n=1). DLTs at 5 mg/m2 were limited to febrile neutropenia (n=2). The 4 mg/m2 dose level was determined as the phase II dose. Toxicities at 4 mg/m2 included gr 1 fatigue (n=8) and neutropenia [gr 1 (n=4), gr 2 (n=7), gr 3 (n=3), gr 4 (n=2)]. Neutropenia nadir was day 6–8 with recovery to gr ≤2 by day 15. Gr 3 non-hematologic toxicities at 4 mg/m2 included gr 3 ALT (n=1), gr 3 AST (n=2), gr 3 hyperbilirubinemia (n=1), gr 3 hypophosphatemia (n=1), and gr 3 alkaline phosphatase elevation (n=1). Median PK values in cycle 1 at 4 mg/m2 were: Cmax 473 ng/ml, AUC0-∞ 5207 ng.hr/ml, and t½ 36 hr. AUC0-∞ and Cmax were proportional to dose. No consistent correlation was observed between DLTs and PK parameters. Stable disease for ≥ 4 cycles (range 4–11) was observed in 6 pts (4 pts at 4 mg/m2; 1 pt at 6 mg/m2; 1 pt at 8 mg/m2). A pt with cholangiocarcinoma had evidence of radiographic tumor regression (post cycle 10) and a >50% decrease in her CA 19–9. Conclusions: The recommended phase II dose of SB-743921 on the Q 21 day schedule is 4 mg/m2. The observed toxicities at the recommended phase II dose are manageable and reversible. The onset and duration of neutropenia is predictable.

[Table: see text]

A multicenter phase 2 consortium (P2C) study of triapine in patients (pts) with advanced adenocarcinoma of the pancreas

14118

Background: Triapine is a small molecule iron chelator that has been shown to inhibit ribonucleotide reductase (RR) at the M2 subunit. Early trials suggested activity in pancreatic cancer. The P2C initiated a study of single agent Triapine as both first-line therapy and for pts with gemcitabine-refractory disease. Correlatives included: pharmacokinetics, MDR polymorphisms, and the effects of Triapine on cell cycle and electron paramagnetic resonance spectroscopy (EPR). Methods: Standard eligibility criteria were used, however, pts with G6PD deficiency were excluded. Triapine was given 96 mg/m2 IV over 2 hours, days 1–4 and 15–18, repeated q 28 days. Primary goals - evaluate survival (S) at 6 mos (previously untreated pts) and 4 mos (refractory pts). Interim analyses were planned when 28 previously untreated and 20 refractory pts were enrolled. Results: 14 eligible pts were enrolled in 10 mos (13 refractory, 9 male). The previously untreated pt received only 1 cycle secondary to progressive disease. Of the 13 refractory pts, 7 pts received at most 2 cycles; 6 received 1. Disease progression precluded further treatment in 11 pts. 6 pts had Gr 4 toxicities at least possibly related to drug, including: neutropenia-4, hyperkalemia-1, hyponatremia-1, leukopenia-1, thrombocytopenia-1, hypophosphatemia-1. 6 pts had a Gr 3 fatigue. One refractory patient expired on study. No responses were seen. Estimated 4 mos S in refractory pts is 16% (95% CI 3–94). EPR studies showed that Triapine led to a loss of the RR tyrosine radical EPR signal. Conclusions: Enrollment was suspended due to excess toxicity and lack of activity in pts refractory to gemcitabine. Correlative studies confirm the mechanism of action of Triapine as a chelating agent on RR. Supported by NCI Grant N01 CM17104 and the NCI Translational Research Fund.

No significant financial relationships to disclose.

New therapies, new directions: advances in the systemic treatment of metastatic colorectal cancer

Colorectal cancer is the second leading cause of cancer death and it is clear that patients with metastatic disease have better quality of life and survival when given treatment. Despite four decades of experience of treating patients with fluorouracil, there remains considerable controversy about the optimum dose and scheduling, as well as biomodulation with leucovorin and methotrexate. However, irrespective of the dose and schedule, overall survival times are poor--about 1 year. Disappointingly, oral agents with similar mechanisms to fluorouracil do not improve survival rates in comparison with fluorouracil and leucovorin treatment. Irinotecan and oxaliplatin are newer agents that have improved the response rates for patients with metastatic disease when they are added to flurouracil and leucovorin. The combination of irinotecan, fluorouracil, and leucovorin has also improved overall survival. These are small advances in the fight against colorectal cancer, and further drug development is necessary.