Trial Information

Phase II Study of Tailored-Dose Docetaxel + Trastuzumab in Her-2 Positive Metastatic Breast Cancer

This is a research study which aims to improve the way that doctors determine the dose of
chemotherapy given to patients. Right now, chemotherapy is determined by a patient's height
and weight. However, some patients metabolize chemotherapy faster or slower than the average
person because of a different level of drug metabolizing enzyme in the liver. Therefore,
some patients are either given too small or too large a dose of chemotherapy because the
amount of enzyme is not taken into account. This research study will examine the use of a
simple test, call the Erythromycin Breath Test(ERMBT) to determine the amount of enzyme
which can metabolize the chemotherapy drug docetaxel (Taxotere). The dose of docetaxel will
be tailored to the amount of enzyme which is available to metabolize the drug for each
patient. The drug, docetaxel, is combined with another drug, trastuzumab (Herceptin),
because at this time this combination appears to be promising in metastatic breast cancer
research.-Patients participating in this study will have biopsy proven, measurable
metastatic breast cancer.

During the study:

- Patients will receive tailored-dose docetaxel and Trastuzumab for their breast cancer.

- There are no sex or age restrictions although the patients in this disease category are
reflective of an adult female population.

Approximately 30 subjects will be recruited at this site.

Diagnosis and Staging • All patients will have primary tumor measurements by physical exam
and/or radiographic studies (CT, MRI, bone scan).

Erythromycin Breath Test*

• The ERMBT will be administered in the outpatient setting, prior to the first cycle of
docetaxel. Twenty minutes after the injection of a trace amount of (14C N-methyl)
erythromycin, (This test assesses the activity of the cytochrome P450 enzyme which is
largely responsible for the metabolism of the chemotherapeutic agent docetaxel.)patients
will exhale through a tube creating bubbles in a solution of hyamine hydroxide, ethanol, and
a blue indicator until 2 mmol of carbon dioxide has been trapped and the blue color
vanishes.

Chemotherapy Regimen

Premedications

- Dexamethasone 8 mg po bid for three days, beginning the day prior to docetaxel
administration.

- Diphenhydramine 50 mg IVPB

- Granisetron 2 mg po 30 minutes pre-docetaxel

Chemotherapy

- Docetaxel, tailored dose, to be infused over 1 hour on day 1 every 3 weeks for the
duration of study.

- Starting dose of docetaxel to be determined by the ERMBT and serum albumin according to
formula as stated in protocol (page 11).

- Trastuzumab, 4 mg/kg to be infused over 90 minutes on day 2 (after pharmacokinetic
sampling).

- Beginning week 2, trastuzumab will be given at a dose of 2 mg/kg weekly throughout
duration of study. (After the first dose of docetaxel, future doses may be given on
the same day as docetaxel).

Suggested post-chemotherapy antiemetics:

- Compazine 10 mg po q 6 hours prn nausea/vomiting Pharmacokinetic Analysis

- All patients will have pharmacokinetic determination with blood drawn for
pharmacokinetic analysis over a 24 hour period after the first docetaxel treatment.
Time points include time 0, 15 minutes, 45 minutes, 180 minutes (3 hours), 390 minutes
(6.5 hours), and 1440 minutes (24 hours).

DEXA Scan*

- DEXA scan will be performed during the patient's stay in the Clinical Research Center,
on the Lunar DPXL Bone Densitometer. This is a very simple and noninvasive test which
uses x-rays and a computer program to analyze the ratio of 38 keV to 70 keV
attenuation. The program then calculates Fat and Lean values for the arms, legs,
abdomen, ribs, and the total body. This is the same test that is in widespread
clinical use for the evaluation of osteoporosis. During the DEXA scan, patients will be
exposed to a trace amount of radiation which is equal to about 2% of the yearly
background dose, or less.

*The amount of radiation to be administered by the erythromycin breath test and DEXA
scan is not medically significant.

- Patients will receive 2 cycles of docetaxel/trastuzumab and be re-evaluated for
response (ever 6 weeks, or later if dosage delays caused lengthening of cycle).

- Responding and stable patients will continue to receive docetaxel therapy, with
evaluations every 2 cycles (every 6 weeks, or later if dosage delays caused lengthening
of cycle).

- Continued treatment beyond 8 cycles will be at the discretion of the patient's primary
oncologist.