Acute Promyelocytic Leukemia

This Phase 3 study in adult participants with newly diagnosed low-risk APL will evaluate the efficacy, safety, and PK of an oral capsule formulation of ATO, in combination with ATRA.

LATITUDE: A Phase 3, Randomized, Open-Label, 3-Cohort, 2-Period, 2- Sequence, Crossover Trial to Evaluate the Pharmacokinetics, Safety, and Efficacy of Oral Arsenic Trioxide Versus Intravenous Arsenic Trioxide for Consolidation Therapy in Participants With Newly Diagnosed, Non-High Risk, Acute Promyelocytic Leukemia Rationale: SDK Therapeutics is developing an oral formulation of arsenic trioxide (ATO) for the treatment of acute promyelocytic leukemia (APL). Patients with APL are usually treated with arsenic trioxide (ATO) through an IV along with all-trans retinoic acid (ATRA) taken by mouth. Receiving ATO through an IV requires patients with APL to go to the hospital a lot and get long treatments (sometimes every day over a year of treatment). This can be hard and uncomfortable. If ATO can be taken by mouth, it would be much easier for patients and their families. Objective: The main objective is to show that the body absorbs the same amount of ATO whether it's taken by mouth or through an IV. Other objectives include checking if ATO taken by mouth works just as well, causes fewer heart problems, is safe, and improves quality of life compared with ATO given through an IV. Main trial endpoints: The main endpoint being measured is how much ATO is in the blood after 5 doses. Another important endpoint is how many patients have no signs of cancer in their blood after 3 rounds of treatment. Secondary trial endpoints: Other things being measured include: whether patients stay cancer-free over 2 years; changes in heart rhythm; side effects and lab test results; how patients feel during treatment; how much of ATO is in the blood; and how often patients feel bothered by side effects. Trial design: This is an open-label study, meaning everyone knows which treatment they are getting. Patients will get 4 rounds of treatment, each lasting 8 weeks. After that, patients will have check-ups every 3 months to assess safety and disease status for a total of 2 years. Trial population: The study includes adults and teens (12 years and older) who have APL, are not high-risk, and have already finished the first part of their treatment (induction) with IV ATO and ATRA. Interventions: There are 3 groups in the study: Cohort A: Takes 0.15 mg/kg Oral ATO for 3 rounds, then switches to 0.15 mg/kg IV ATO for part of the 4th round. Cohort B: Takes 0.15 mg/kg IV ATO for 3 rounds, then switches to 0.15 mg/kg Oral ATO for part of the 4th round. Cohort C: Takes 0.15 mg/kg Oral ATO for all 4 rounds. All cohorts also take 45 mg/m2/day ATRA during certain weeks of each round. Doctors will assess efficacy by checking bone marrow samples before and during treatment to see if the cancer is gone. Special lab tests will be used to look for cancer cells. Safety will be assessed by checking for side effects using blood tests, heart tests, physical exams, and other health checks. Quality of life will be assessed by the patients who will fill out surveys about how they feel during treatment and how much the side effects bother them. The study will also look at how often patients need to go to the doctor or hospital; how treatment affects daily life and work; and how satisfied patients are with their treatment.

The investigators have formulated an oral preparation of arsenic trioxide (oral-ATO), and shown that it is efficacious for APL in R1, inducing CR2 in more than 90% of patients \[8,9\]. Furthermore, in an effort to prevent relapse, the investigators have moved oral-ATO forward to the maintenance of CR1. This strategy results in favorable overall-survival (OS) and leukemia-free-survival (LFS) \[10\], implying that prolonged treatment with oral-ATO may prevent relapses. Current protocols have incorporated i.v.-ATO in the treatment of newly-diagnosed APL \[11-15\]. For regimens comprising oral-ATO, ATRA and chemotherapy, 5-year OS in excess of 90% is achieved \[11-15\]. The investigators have also published long-term data showing the use of oral-ATO is highly effective and safe in the relapsed and frontline settings \[16,17\]. In this study, the investigators evaluate the use of oral-ATO and ATRA based induction regimens in newly diagnosed patients with APL with no of minimal chemotherapy in a prospective multicentre phase 2 study.

The trial is open to all patients with a diagnosis of acute promyelocytic leukemia (APL) who are PCR-positive for the PML-RARα transcript and less than 18 years of age.