Phase I/II, FIH, Dose Escalation Trial of TL-895 and Expansion of TL-895 Monotherapy and Combination Therapy With Navtemadlin in Tx-Naïve and R/R CLL/SLL Subjects

The purpose of this research study is to determine the safety and tolerability of TL-895. There are 2 parts of this study. Part 1 tested increasing doses of TL-895 to identify the recommended safe dose for participants with relapsed/refractory (R/R) B cell malignancies who failed at least 1 but no more than 3 prior therapies. Part 1 of this study is no longer enrolling participants.

Arms 1 & 2 of Part 2 of this study will test different doses of TL-895 in participants with R/R CLL or SLL who have failed at least 1 prior therapy. Arms 1 & 2 of Part 2 of this study is randomized (like the flip of a coin) to receive a specific treatment dose. If someone participates in arms 1 or 2 of Part 2, the dose they receive will be either 100mg twice a day or 150mg twice a day.

Arms 3 and 4 of Part 2 of this study will test the 150mg and 100mg BID dose of TL-895, respectively in treatment naïve participants with CLL/SLL.

Arms 5 and 6 of Part 2 will test 150mg TL-895 BID in combination with 240 mg navtemadlin QD in participants with relapsed/refractory and treatment naïve without 17p(del). Arm 7 will test 150mg TL-895 in combination with 240 mg navtemadlin QD in participants with relapsed/refractory CLL/SLL with 17p(del).

Every participant in this study will receive TL-895.