Inclusion Criteria:
- Patients with a diagnosis of nonmetastatic or metastatic breast cancer in complete
clinicla response classic HER2pos (ie, IHC 3+ or FISHpos) breast cancer (BC) who have
previously been vaccinated with DC1 HER2-pulsed vaccines on any of several prior
clinical trials for ductal carcinoma in situ (DCIS) or inflammatory breast cancer
(IBC) are eligible; however, we also allowed HER2 2+ patients in many of these prior
trials and they will also be allowed to participate in this trial. Note: HER2pos BC is
defined by tumor tissue HER2 overexpression and or tumor HER2 amplification. The lack
of HER2 overexpression by IHC is defined as 0 or 1+ whereas overexpression is defined
as 3+. In the event of equivocal IHC, 2+, the tumor must be gene-amplified by
fluorescent in situ hybridization (FISH) performed upon the primary tumor or
metastatic lesion (ratio > 2 and HER2 copy number > 4 define HER2negdisease).
- Patients with nonmetastatic HER posBC must have completed all standard-of-care
treatment for nonmetastatic BC (e.g., surgery, chemotherapy, radiation therapy, and
HER2-targeted therapy). Note: antiestrogen therapy is permitted while on trial. Note:
antiestrogen therapy is permitted while on trial.
- Patients with diagnosis of metastatic HER2 pos breast cancer must have complete tumor
response to current treatment per RECIST 1.1 and completed all standard-of-care
chemotherapy. Note: maintenance treatment with approved HER2-targeted agents and/or
antiestrogen therapy is permitted while on trial.
- Age ≥ 18 years.
- Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
- Participants must have normal organ and marrow function within 2 weeks of
registration.
- For both male and female patients, effective methods of contraception must be used
throughout the study and for 3 months following the last dose.
- Must have the ability to understand and the willingness to sign a written informed
consent prior to registration on study.
Exclusion Criteria:
- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, congenital prolonged QT syndrome, symptomatic congestive heart failure,
unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations
that would limit compliance with study requirements.
- Current use of immunosuppressive agents or systemic corticosteroids. Topical, ocular,
intra-articular, intranasal, inhalational corticosteroids (with minimal systemic
absorption) are allowed. Patients who have received systemic corticosteroids ≤ 30 days
prior to starting study drug will be excluded.
- No other prior malignancy is allowed except for the following:
- Adequately treated basal cell or squamous cell skin cancer
- In situ cervical cancer
- Any other cancer from which the patient has been disease free for at least 3
years.
- Pregnant or breast feeding.
- Known to be HIV positive.
- Known current or a history of hepatitis B or C virus, including chronic and dormant
states, unless disease has been treated and confirmed cleared.
- Major surgery within 4 weeks of initiation of study drug.
- Have not recovered to ≤ Grade 1 or tolerable Grade 2 adverse events (AEs) due to
agents administered ≥ 28 days earlier, as documented by the treating investigator.
- Currently enrolled in any other clinical protocol or investigational trial that
involves administration of experimental therapy and/or therapeutic devices, or
investigational drug. Note: patients enrolled on another HER2 vaccine trial but not
receiving active therapy are allowed to enroll in this study.
- Not able to comply with the treatment schedule and study procedures for any reason.
