A Study With NKT5097 for Adults With Advanced/Metastatic Solid Tumors

Inclusion Criteria:

* Able to provide written informed consent
* Advanced unresectable or metastatic solid tumor (Part 1, 2 \& 3 only)
* Advanced unresectable or metastatic HR+/HER2- breast cancer (Part 4 \& 5 only)
* Refractory to or unable to tolerate existing therapies (Part 1, 2 \& 4 only)
* Measurable or evaluable disease (Part 1, 2, \& 4 only).
* Measurable disease (Part 3 \& 5 only)
* Eighteen years of age or older
* ECOG status of 0 or 1
* Adequate organ function
* Patients with female reproductive organs must be surgically sterile, post- menopausal or willing to use effective contraception per protocol
* Patients who are capable of insemination must be willing to use highly effective contraception and to refrain from sperm donation during treatment and for 28 days after the last dose
* Able to swallow oral meds
* Willing to provide tumor tissue

Exclusion Criteria:

* Advanced solid tumor that is a candidate for curative treatment
* History of another malignancy except for the following: adequately treated local basal cell or squamous carcinoma of the skin, in situ cervical cancer, adequately treated papillary noninvasive bladder cancer, other adequately treated Stage I or Stage II cancers currently in complete remission
* Not recovered from the effects of prior anticancer therapy
* Clinically significant cardiovascular event, including myocardial infarction, arterial thromboembolism, or cerebrovascular thromboembolism, within 6 months
* Known active CNS metastases and/or carcinomatous meningitis
* Active interstitial lung disease requiring treatment
* History of uveitis, retinopathy, or other clinically significant retinal disease
* Major surgery within 30 days of administration of first dose
* Active uncontrolled infectious disease
* Significant liver disease (Child Pugh class B or C)
* Should not have received any prior selective investigational inhibitors or degraders (Part 5 only)