Phase I/II study of neoadjuvant bevacizumab with radiation therapy and 5-fluorouracil in patients with rectal cancer: initial results

4041

Background: A phase I/II study of neoadjuvant bevacizumab with 5-fluorouracil and radiation therapy in patients with locally advanced rectal cancer was undertaken to determine whether inhibition of VEGF is safe and has clinical benefits by enhancing chemo- radiation therapy. Methods: 22 patients with endoscopic ultrasound or surface coil MRI staged T3/T4 non-metastatic rectal cancer were enrolled from 2001–2006. All patients completed 4 cycles of neoadjuvant therapy including: 1) bevacizumab infusion (5 or 10 mg/kg) on day 1 of each cycle; 2) peripheral venous infusion 5-FU (225 mg/m2/24 hours) administration each treatment week of cycles 2 - 4; 3) external beam irradiation delivery (50.4 Gy in 28 fractions over 5.5 weeks); and 4) surgery 7 to 9 weeks after completion of all neoadjuvant therapy. Correlative studies were undertaken before and during the trial. We collected serial tumor biopsies, PET-FDG scans, and analyzed blood and urine for potential biomarkers. Results: Mean pre-therapy tumor size was 4.7 cm (2–9 cm). Post-treatment surgical specimens usually had well-demarcated shallow ulcerations with a mean diameter of 2.4 cm (0.7–6 cm). In response to the neoadjuvant regimen, all patients had significantly (p<0.01) decreased FDG-uptake by PET. Histologic examination showed no residual primary cancer in 5 patients (ypT0). Of 17 patients with residual disease, microscopic disease usually occurred as malignant glands embedded in fibrosis (ypT1 in 3 patients, ypT2 in 4 patients, ypT3 in 10 patients). Downstaging was seen in 12/22 tumors. 8 patients had microscopic nodal metastases. Bevacizumab alone and combined treatment were both associated with increased plasma VEGF and PlGF levels in 18/18 patients (P<0.01 at all 4 timepoints compared to baseline). Viable CECs were decreased by VEGF blockade at day 3 (P<0.01 compared to baseline), and peak CEC levels during treatment was correlated with histologic tumor response (2.77 [1.18–3.18] for T3 patients, n=9 versus 1.14 [0.82–1.53] for T0-T2 patients, n=12; p=0.05). Conclusions: Addition of bevacizumab at a dose of 5 mg/kg to standard chemo-radiation is safe in patients with locally advanced rectal cancer. Bevacizumab is active and the combined regimen yields promising results.

[Table: see text]

Phase II study of FOLFOX, bevacizumab and erlotinib as first-line therapy for patients with metastatic colorectal cancer

BACKGROUND

Targeting the epidermal growth factor receptor and angiogenesis have proven useful strategies against metastatic colorectal cancer. The benefit of combining inhibitors of both pathways is unknown.

PATIENTS AND METHODS

Patients with previously untreated metastatic colorectal cancer were enrolled in a phase II trial of infusional 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX), bevacizumab and erlotinib. The primary end point was progression-free survival.

RESULTS

Thirty-five patients were enrolled and all came off trial for reasons other than progression; 18 (51%) had protocol-defined adverse events requiring removal, nine (26%) withdrew consent due to toxicity, six pursued surgery or localized therapies and two requested a treatment holiday. Principal toxic effects included rash, neuropathy and diarrhea. Seven patients came off trial before first restaging. By intention-to-treat analysis, one patient had a confirmed complete response, 10 had confirmed partial responses and one had an unconfirmed partial response (response rate = 34%). One patient had progressive disease at time of withdrawal from the trial, thus progression-free survival could not be calculated.

CONCLUSION

The combination of FOLFOX, bevacizumab and erlotinib led to higher than expected early withdrawal due to toxicity, limiting conclusions regarding efficacy. These findings raise concern regarding the tolerability of adding more agents to already complex combination regimens for metastatic colorectal cancer.

Phase II study of cetuximab in patients with unresectable or metastatic hepatocellular carcinoma

14096

Background: Patients with advanced hepatocellular carcinoma (HCC) have a poor prognosis with no established systemic treatment regimen. Epidermal growth factor receptor/human epidermal growth factor receptor 1 (EGFR/HER1) and ligand expression is frequently seen in HCC. Recent studies suggest that erlotinib, an EGFR/HER1 tyrosine kinase inhibitor, may have benefit in stabilizing HCC. We performed a phase II study with cetuximab, a chimeric monoclonal antibody that binds selectively to EGFR, in advanced HCC. Methods: Eligibility criteria include unresectable or metastatic measurable HCC, up to two prior systemic regimens, performance status ≤ 2, CLIP score ≤ 3, and adequate organ functions. The initial dose of cetuximab is 400 mg/m2 intravenously (IV) administered over 120 minutes, followed by weekly infusions at 250 mg/m2 IV over 60 minutes. Each cycle is defined as 6 consecutive weekly treatments. EGFR expression was assayed by immunohistochemistry and trough serum concentrations of cetuximab were determined during the first cycle. The primary endpoint of the study was progression free survival (PFS). Results: The planned 30 patients have been enrolled: median age = 58 (33–82), M/F = 23/7, ECOG 0/1/2 = 16/12/2, CLIP 0/1/2/3=2/9/14/5. No responses were seen. Five patients had stable disease. The median number of cycles on study per patient was 1 (range, 1–3). 16 patients developed progressive disease following one cycle of treatment. Only one patient remains on study. The median PFS and OS were 41 days (95% CI, 36 to 79) and 157 days (95% CI, 112 to not available), respectively. The treatment was generally well tolerated. No treatment related deaths occurred. Treatment related grade 1–2 toxicities included rash (83%), fatigue (47%), hypomagnesemia (27%), nausea (20%), anemia (13%), diarrhea (13%), anorexia (13%), and elevation of SGOT/SGPT (10%). Grade 3 SGOT, hypomagnesemia, and fever without neutropenia were seen in one patient (3%) each. Conclusions: Cetuximab has no activity in HCC in this phase II study. It can be safely given with tolerable toxicity profiles in HCC patients. Updated information on toxicity, efficacy, EGFR expression and pharmacokinetics will be presented at the meeting. Supported by Bristol-Myers Squibb.

[Table: see text]

Phase II study of FOLFOX, bevacizumab and erlotinib as initial therapy for patients with metastatic colorectal cancer (MCRC)

3545

Background: Cytotoxic chemotherapy with targeted therapy against the vascular endothelial growth factor (VEGF) or the epidermal growth factor receptor (EGFR) has become a standard approach in MCRC, though combining VEGF and EGFR inhibition with chemotherapy as initial treatment is not well established. We conducted a phase II study of the combination of infusional 5-fluorouracil (5-FU), leucovorin, oxaliplatin (FOLFOX), bevacizumab, and erlotinib in chemotherapy naïve patients with MCRC. Methods: Eligible patients had measurable MCRC, no prior systemic therapy for MCRC or at least one year since completion of adjuvant therapy (only 5-FU and leucovorin acceptable), performance status 0–1. The regimen consisted of 14-day cycles of FOLFOX started on day 1 (oxaliplatin 85 mg/m2, bolus 5-FU 400 mg/m2, leucovorin 400 mg/m2 and 46-hour infusion 5-FU 2.4 g/m2), day 1 bevacizumab 5 mg/kg and erlotinib 150 mg daily. This isa single stage trial with goal of 35 patients. The primary endpoint was progression-free survival (PFS). Results: Between Jan and Dec 2005, 31 patients have been enrolled with the following characteristics: male/female, 19/12; PS ECOG 0/1, 15/16; median age 58, range 38–81. Of the 28 patients who completed at least 1 cycle, the most common grade 3/4 adverse events include: 8/28 (29%) diarrhea, 8/28 (29%) neutropenia, 5/28 (18%) rash, 4/28 (14%) fatigue, 3/28 (11%) nausea/vomiting, 3/28 (11%) neuropathy. 22/28 (78%) of patients had at least 1 grade 3/4 toxicity. 14/31 patients remain on trial, 13/31 (42%) came off for toxicity or withdrew consent due to treatment-related toxicities, 4 withdrew consent for other reasons. Efficacy data is not available at time of submission but will be more mature by June 2006. Conclusions: The combination of FOLFOX, bevacizumab and erlotinib appears to have moderate toxicity, with ∼40% of patients coming off trial due to side effects. Further characterization of the tolerability profile will be necessary when interpreting the efficacy of the combination. We expect full accrual as well as reasonable point estimates of PFS by June 2006. Supported by: Sanofi-Synthelabo, a member of the Sanofi-Aventis group, Genentech

[Table: see text]

Pharmacokinetics of PT523, a novel aminopterin analogue, in patients with solid tumors

2052

Background: Nα-(4-Amino-4-deoxypteroyl)-N5-hemiphthaloyl)-L-ornithine (PT523) is a nonpolyglutamatable aminopterin analogue selected for clinical evaluation based upon properties that confer potential therapeutic advantages over classic and nonclassic antifolates. This report describes the pharmacokinetic (PK) behavior of PT523 in cancer patients as determined in the first phase I trial of the drug. Methods: Adult patients with refractory solid tumors received PT523 as a 5 min iv infusion every 7 days for 3 weeks. Plasma samples were obtained at -5, 4, 10, 15, 20, 30, 45 min; 1, 2, 3, 4, 6, 8, 24, and 48 h after starting the first weekly infusion. Urine was collected and pooled from 0–8, 8–24, and 24–48 h. An LC/MS assay was used to measure PT523 in plasma and urine. Interday accuracy and precision were both <15% at the lowest concentrations measured in plasma (0.50 ng/mL) and urine (50 ng/mL). PK parameters were estimated by standard noncompartmental methods. Results: The PK of PT523 was characterized in 24 patients with normal renal and hepatic function, and a median age of 52 years (range, 28 - 77 years). Data was obtained from groups of at least three patients receiving doses of 5, 6.7, 9, 12, and 16 mg/m2. The PT523 concentration in plasma decreased in a polyexponential manner and the terminal log-linear phase was achieved 4–6 h after dosing. In the 7 patients receiving doses of 16 mg/m2, the mean peak drug concentration in plasma (Cmax) was 5,650 ± 300 ng/mL and the median plasma concentration 48 h after dosing was 1.7 ng/mL (range, 1.0 - 23.4 ng/mL). The apparent biological half-life (t1/2,z), total body clearance (CL) and apparent volume of distribution at steady-state (Vss) were all independent of the dose. Mean ± SD values of PK parameters for the entire cohort of 24 patients were: CL, 1.16 ± 0.31 L/h/m2; t1/2,z, 5.3 ± 1.2 h; Vss, 7.7 ± 1.5 L/m2. The mean amount of the dose excreted as unchanged drug in urine over 48 h was 40 ± 15%. Conclusions: PT523 exhibits linear PK with moderate interpatient variability when administered as a 5 min iv infusion at doses of 5 - 16 mg/m2. Renal clearance is a major route of elimination. Association between the CL of PT523 and creatinine clearance should be evaluated in a future study to assess whether dose modification is warranted for patients with diminished renal function.

No significant financial relationships to disclose.

High dose radiation therapy and chemotherapy as induction treatment for stage III nonsmall cell lung carcinoma

BACKGROUND

The current study was conducted to review the authors' experience in treating consecutive patients with American Joint Committee on Cancer (1997 revision) Stage III nonsmall cell lung carcinoma with aggressive preoperative chemoradiation followed by surgical resection.

METHODS

The records of all patients who received preoperative chemoradiation were evaluated. Patients received 2 cycles of concurrent cisplatin and etoposide with 5940 centigrays of radiation therapy. They then were reevaluated to determine whether they were surgical candidates. If so, resection of the primary tumor with mediastinal lymph node dissection was performed 4-6 weeks after the completion of preoperative treatment. After adequate healing, an additional four cycles of cisplatin/etoposide or carboplatin/paclitaxel was given.

RESULTS

Forty-two patients received preoperative chemoradiation, 33 of whom underwent surgical resection (79%), including 9 patients who underwent pneumonectomies. Complete pathologic responses were observed in 27% of these patients. Postoperative complications were noted in 21% of the patients and included persistent air leak, supraventricular arrhythmia, and empyema. There were no reported treatment-related deaths. The median follow-up was 26 months. The overall 5-year survival rate for all patients was 36.5% and was 45. 3% for patients who underwent resection. A trend toward increased 5-year survival was observed in patients who had a complete pathologic response (57.1%). Univariate analysis revealed the N stage classification to be significant for predicting a complete response. Patterns of failure revealed the brain to be the most common site of first recurrence (50%) and the only site of recurrence in 36% of patients. There was only one case of local failure.

CONCLUSIONS

Preoperative chemoradiation using high radiation doses is feasible with acceptable toxicity. The results of the current study suggest an increased complete pathologic response rate and increased overall survival rate compared with reports in the published literature.

A phase II study of gemcitabine and 5-fluorouracil in metastatic pancreatic cancer: an Eastern Cooperative Oncology Group Study (E3296)

Gemcitabine has recently been compared favorably to 5-fluorouracil (5-FU) as the standard chemotherapy for advanced pancreas cancer. Based on phase I data that combining gemcitabine with 5-FU is safe and has evidence for clinical activity, a phase II trial was conducted by the Eastern Cooperative Oncology Group (ECOG). Patients with metastatic disease, good performance status and organ function were eligible and enrolled after providing informed consent. Patients were given gemcitabine (1,000 mg/m(2)) followed by 5-FU (600 mg/m(2)) weekly for 3 weeks of every 4. Of 37 patients enrolled over a 3-month period, 36 were eligible. Partial responses were seen in 5 patients (14%). Median survival was 4.4 months with a 1-year survival rate of 8.6%. A randomized trial of the combination of 5-FU and gemcitabine versus gemcitabine alone is currently accruing patients in ECOG.

Treatment of advanced and metastatic pancreatic cancer

The majority of adenocarcinoma of the pancreas are non-resectable at diagnosis due to locally advanced or metastatic disease. There will be an estimated 28,900 new cases of pancreatic cancer diagnosed in the United States in 1998. In data collected from 1986-1993, the five year survival of all stages combined was 4%. Realizing that most patients present with advanced disease, and there are no acceptable screening methods to detect early stage disease, efforts to develop active anti-cancer agents with minimal toxicity are essential in order to improve the quality of life and survival. Several 5-fluorouracil based regimens have been tried without a significant impact on palliation or survival. Recently, the anti-metabolite gemcitabine has been approved for use in individuals with locally advanced and metastatic disease, primarily on the basis of improved functional status. Many cytotoxic agents have proven ineffective in the treatment of this disease. There are several ongoing studies investigating the role of new cytotoxic and biologic agents.