Safety and Efficacy of KLS-1 Monotherapy in Malignant Neoplasms

The goal of this clinical trial is to test the safety and preliminary efficacy of a new drug, KLS-1, in adults with different types of solid tumors and chronic lymphocytic leukemia (CLL). The main questions it aims to answer are: * To define Dose Limiting Toxicities (DLT) and maximum tolerated dose (MTD) of KLS-1 * To select the recommended Phase II Dose (P2D) of KLS-1 * To determine the single dose and multiple dose PK profile following IV administration of KLS-1 * What is the safest and most effective dose of KLS-1? * Does KLS-1 show anti-tumor activity in patients? * To evaluate preliminary efficacy of KLS-1 in up to 4 cohorts of locally advanced or metastatic solid tumor (malignant melanoma, prostate cancer, pancreatic cancer), or CLL. * To evaluate 12-months progression-free survival (PFS) and duration of response (DOR) follow-up after the last dose of KLS-1 Participants will: * Receive KLS-1 through intravenous (IV) infusions in 21-day cycles. * Be monitored for side effects and improvements in their malignancy. Investigators will compare different doses of KLS-1 in the initial phase to find the best dose for Phase II. Once the P2D is defined, it will be tested in a larger group to see its effects on locally advanced or metastatic solid tumor (malignant melanoma, prostate cancer, pancreatic cancer) and CLL.