CAR-macrophages for the Treatment of HER2 Overexpressing Solid Tumors

Inclusion Criteria:

* HER2-positive recurrent or metastatic solid tumors for which there are no available curative treatment options.

  * Breast cancer and gastric/gastroesophageal junction cancers must have failed approved HER2-targeted agents.
  * Other HER2-positive tumor types must have failed standard of care therapies, while prior therapy with anti-HER2 drugs is not required.
* Subject must be willing and able to undergo tumor tissue biopsy procedures
* Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
* Subject has adequate bone marrow and organ function

Exclusion Criteria:

* HIV, active hepatitis B or hepatitis C infection.
* Diagnosis of immunodeficiency or chronic exposure to systemic corticosteroid therapy or any other form of immunosuppressive therapy
* Untreated or symptomatic central nervous system (CNS) metastases or cytology proven carcinomatous meningitis.

  o Subjects with small, asymptomatic CNS metastases that do not require treatment are permitted to enroll.
* Left ventricular ejection fraction (LVEF) \<50% as determined by ECHO or multiple gated acquisition scan (MUGA)

Other protocol-defined Inclusion/Exclusion may apply.

CT-0508 in Combination with Pembrolizumab Substudy Only:

Exclusion Criteria:

* Subjects with severe hypersensitivity (≥Grade 3) to pembrolizumab and/or any of its excipients
* Subjects with an active autoimmune disease that has required systemic treatment in past 2 years (i.e., with use of disease modifying agents, corticosteroids or immunosuppressive drugs).
* Subjects who have a history of (non-infectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease
* Subjects who have had an allogeneic tissue/solid organ transplant