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A Randomized Open Label Clinical Trial of Fixed Dose Letrozole vs. Titrated Letrozole for In Vitro Fertilization With Cryopreservation of Oocytes and Embryos in Breast Cancer Patients

19 Years
45 Years
Open (Enrolling)
Breast Cancer, Infertility

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Trial Information

A Randomized Open Label Clinical Trial of Fixed Dose Letrozole vs. Titrated Letrozole for In Vitro Fertilization With Cryopreservation of Oocytes and Embryos in Breast Cancer Patients

IVF is a process which involves a schedule of injectable medication to recruit several
follicles, each containing an egg, to be retrieved under ultrasound guidance where they can
be fertilized. Embryos are then selected to be transferred back into the patient's uterus or
are cryopreserved and transferred at a later date.

Letrozole is a potent and highly selective third generation aromatase inhibitor that was
developed in the early 1990's. Aromatase is an enzyme of the cytochrome P-450 superfamily
and the product of the CYP19 gene, which catalyzes the reaction that converts androgenic
substances to estrogens in many tissues, including the granulosa cells of ovarian follicles.
Letrozole competitively inhibits the activity of the aromatase enzyme and has a half-life of
approximately 48 hours. Because of its potent, sustained suppression in the plasma levels of
estradiol, this drug has been recently found to be superior to tamoxifen in the treatment of
advanced-stage post-menopausal breast cancer. Conventional ovarian stimulation often results
in very high estrogen levels. Since the high estrogen levels are often unsafe for breast
cancer patients, fixed dose aromatase inhibitor protocols with Letrozole were developed, to
achieve effective ovarian stimulation with reduced estrogen levels to prevent tumor
progression and short-term cancer recurrence.

A fixed dose of Letrozole has been used off-label as an ovulation induction agent in many
centers to stimulate egg development for infertile couples and patients prior to undergoing
chemotherapy for estrogen sensitive cancers.

The purpose of our study is to determine if titrated dose Letrozole in comparison to fixed
dose Letrozole during gonadotropin stimulation in IVF in breast cancer patients results in
lower estradiol levels and higher mature oocyte yield.

In patients who are scheduled to undergo treatment with IVF for fertility preservation due
to breast cancer, we would like to prospectively randomize them to fixed dose vs. titrated
dose of Letrozole. Due to time restraints for chemotherapy patients may present for ovarian
stimulation prior to Day 2 of their menstrual cycle. If this were to occur, Ganirelix may be
started to suppress the pituitary hormones for down regulation prior to starting stimulation
medications until day 2 of menstrual bleeding. Eligible subjects will be fully informed
about the nature of the trial. Subjects could be enrolled for IVF treatment at any point
after breast cancer diagnosis following surgery but before the initiation of chemotherapy,
if chemotherapy has been prescribed by their oncologist. After obtaining written informed
consent, the subjects will be screened based on inclusion/exclusion criteria, medical and
infertility history, Day 2/3 FSH and estradiol, physical and gynecological examination,
oncology clearance and the Center's standard screening evaluations for IVF patients. A
thorough gynecologic and endocrinologic evaluation will be performed before the start of any
treatment. Laboratory assessments will include CBC, chemistry and lipid profile (see
attached history and physical form). Vital signs including blood pressure, pulse, and weight
will be assessed at baseline (prior to start of stimulation medication), with preoperative
evaluation, on day of egg retrieval, and with post retrieval visits.

Patients will have serum blood tests for bHCG, FSH, AMH, Estradiol, and LH and vaginal
sonogram on the second day of menstrual bleeding. Start of stimulation medication will
proceed only with documentation of a serum negative pregnancy test. Patients will only be
eligible to participate in the study for one cycle of in vitro fertilization.

Patients who elect to participate in the study will be provided with gonadotropin

The starting dose of gonadotropins for both study groups would be determined by the
patients' age and by antral follicle counts assessed by transvaginal ultrasound at the time
of initial consultation. See below:

Age <35 , Antral follicle Count >15 gonadotropin dose 225 IU (150 IU FSH + 75 IU HMG; Age
<35, Antral follicle Count <15 gonadotropin dose 300 IU (150 IU FSH + 150 IU HMG; Age
35-39, Antral follicle Count >10 gonadotropin dose 300 IU (150 IU FSH + 150 IU HMG; Age
35-39, Antral follicle Count <10 gonadotropin dose 450 IU (225 IU FSH + 225 IU HMG; Age>40
Independent of antral follicle count, gonadotropin dose 450 IU (225 FSH + 225 IU HMG);

All patients would also be given a daily medication to prevent them from ovulating
(Ganirelix), no later than cycle day #7 and continuing until HCG administration.

Group#1-Fixed Letrozole Group: Provided their blood tests and sonograms were within normal
limits, patients who are randomized to fixed dose Letrozole will start Letrozole 5mg daily
(orally) on the second day of their menstrual cycle and then gonadotropins on the fourth day
of their menstrual cycle (Current Letrozole protocol at CRMI). Patients will be monitored
with daily blood tests for estradiol and LH and sonogram every 1-3 days. Adjustments to
gonadotropin dosing will be made as per usual protocol for IVF. Letrozole dose will not
change and will continue for two weeks after egg retrieval.

Group #2-Titrated Letrozole Group: Provided their blood tests and sonograms were within
normal limits, patients who are randomized to the titrated dose of Letrozole, will start
gonadotropins in the evening of day #2 of their menstrual cycle with injectable follicle
stimulating hormone (FSH) and human menopausal gonadotropin (HMG). Oral Letrozole will be
added to the stimulation in the following titrated regimen:

Serum Estradiol level <150 pg/ml- No Letrozole; Serum Estradiol Level 150-250 pg/ml- 2.5mg;
Serum Estradiol Level 251-350 pg/ml- 5 mg; Serum Estradiol Level >350 pg/ml - 7.5 mg;

The maximal starting dose of Letrozole will be 5 mg, regardless of the initial estradiol
level. The Letrozole dose may be reduced if the appropriate suppression of estradiol occurs.
The maximal increase or decrease in Letrozole dose will be 2.5 mg/ day. Patients will be
monitored with blood tests for estradiol and LH and sonograms starting on the second day of
gonadotropin stimulation and every 1-3 days to monitor response and adjust medication dose
as per our usual IVF protocol. Letrozole will be stopped for both groups on the day that HCG
is given and resumed after egg retrieval. All patients will stay on the same dose of
Letrozole that was required for their last day of ovarian stimulation for 2 weeks after
stimulation to keep estradiol levels at a minimum. In addition, patients will have serum
estradiol levels drawn weekly for 2 weeks after stimulation. Follow-up vital signs will be
recorded along with CBC, liver function panel, and cholesterol panel 2 weeks after
stimulation. They will also be asked to return 6 months to 1 year after completion of
chemotherapy for AMH and FSH levels to evaluate ovarian reserve, and then followed on a
yearly basis by phone/mail questionnaire or in person with an annual gynecological

All study patients will be provided with an emergency 24-hour phone number to reach a
physician to report adverse reactions to medications, and these physicians will file adverse
event report forms to the principal investigator and data safety monitoring board. In
addition, they will be asked to report any adverse reactions to medications during
follicular monitoring sonograms. All decisions regarding daily medication doses will be
determined by the study principal investigator. Otherwise, the treatment of ovarian
stimulation, egg retrieval, and cryopreservation is identical to non-study patients
undergoing ovarian stimulation, oocyte retrieval, and embryo/oocyte cryopreservation.

Two weeks after retrieval, follow-up instructions will be reviewed. Patients will be advised
to refrain from embryo transfer for a minimum of 2 years after chemotherapy. Patients will
not be permitted to undergo embryo transfer for a minimum of one year after completing
chemotherapy and only after clearance for pregnancy has been obtained from their medical
oncologist. Patients will be followed for five years on an annual basis with a follow-up
telephone call from one of the investigators inquiring about health status (see patient
follow-up data sheet). A pregnancy registry will be created for any pregnancy occurring
following enrollment in the study. Detailed pregnancy outcome will be collected between age
2-5 years (see baby follow-up data sheet attached).

Inclusion Criteria:

- Female breast cancer patient with breast cancer diagnosis after surgery and before
undergoing chemotherapy desiring fertility preservation with oocyte or embryo

- Healthy subject according to documented medical history and physical examination who
has been diagnosed with breast cancer (estrogen and progesterone receptor positive
and/or negative)

- Age less that 45 years at time of informed consent

- Verbal or written clearance from medical or surgical oncologist to undergo controlled
ovarian hyperstimulation-IVF

- Delay to chemotherapy treatment will not jeopardize cancer treatment outcome

- Ovarian stimulation will not affect cancer treatment plan

- Transvaginal ultrasound scan (US) within one month of starting stimulation with no
clinically significant pelvic mass

- Serum FSH level (Day 2-4) less than 25

- Negative pregnancy test prior to beginning Letrozole or gonadotropin therapy

- Willing and able to comply with the protocol

- Voluntary provision of written informed consent, prior to any study related procedure
that was not part of normal medical care, with the understanding that the subject can
withdraw consent at any time without prejudice to her future medical care

- Willingness to provide follow-up information on herself and babies born as part of
this study

Exclusion Criteria:

- Patients not medically cleared by their oncologist

- Patients with stage IV breast cancer based on the poor prognosis, general health of
the patient, and higher uncertainty with delaying chemotherapy

- Any clinically relevant abnormal laboratory value (FSH >25 miu/ml, renal function,
(greater than two times normal value), hepatic function (greater than two times
normal value), blood biochemistry, hematology (elevated white blood count greater
than 1.5 times the normal value, hemoglobin <10mg/dL, thrombocytopenia), abnormal
cholesterol profile (total cholesterol ≥ 300mg/dL, abnormal LDL greater than 2 times
normal value,) based on a fasting sample during the screening phase

- Contraindications for the use of gonadotropins (i.e. Tumors other than breast cancer,
pregnancy, lactation, undiagnosed vaginal bleeding)

- Recent or current medical conditions where the patient is not medically stable to
undergo stimulation or egg retrieval, HIV infection, diabetes, cardiovascular
disease, gastrointestinal, hepatic disease, undiagnosed pelvic mass, renal or
pulmonary disease

- History or presence of alcohol or drug abuse within 12 months of signing consent

- History of severe allergic or anaphylactic reactions or hypersensitivity to any of
the concomitant medication prescribed as part of the treatment regimen in this

- Administration of investigational drugs within three months prior to signing the
informed consent

- Use of insulin sensitizing agents at least one month prior to signing informed

- Any patient who is not a candidate for IVF

Type of Study:


Study Design:

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Outcome Measure:

percent of mature oocyte yield

Outcome Time Frame:

1-2 month

Safety Issue:


Principal Investigator

Glenn Schattman, MD

Investigator Role:

Principal Investigator

Investigator Affiliation:

Weill Cornell Medical Cornell


United States: Food and Drug Administration

Study ID:




Start Date:

November 2009

Completion Date:

October 2015

Related Keywords:

  • Breast Cancer
  • Infertility
  • Letrozole
  • IVF (in vitro fertilization)
  • Cryopreservation
  • Fertility Preservation
  • Breast Cancer
  • Breast Neoplasms
  • Infertility



Weill Cornell Medical College New York, New York  10021