SillaJen has picked up U.S. FDA clearance to expand testing of its experimental cancer drug BAL0891 to include patients with relapsed or refractory acute myeloid leukemia (AML), while also buying out the rights to the candidate in a move that could eliminate future royalty and milestone obligations.

The Korean biotech said Monday that the FDA approved an investigational new drug (IND) amendment allowing BAL0891, a first-in-class dual kinase inhibitor originally developed for solid tumors, to now be studied in AML patients. 

The compound is already being tested in a phase 1 trial in the U.S. for use in certain solid tumors, including triple-negative breast cancer and gastric cancer. The newly added study arm will examine the safety and appropriate dosage of BAL0891 in leukemia patients. According to the company, the trial is expected to enroll a total of about 260 patients across 12 U.S. cancer centers and conclude by March 2026.

In a separate announcement on Monday, SillaJen said it had acquired global rights to BAL0891 from the drug’s original developer, Crossfire Oncology, a Netherlands-based company specializing in kinase inhibitors, for 2 million Swiss francs, or about $2.4 million. 

The acquisition includes two patents tied to the compound’s structure and its potential use in identifying treatment-eligible patients. The company said the deal eliminates future royalty and milestone payments that would have otherwise been owed to Crossfire under a previous licensing agreement.

BAL0891 is described as a “dual kinase inhibitor,” meaning it targets two enzymes involved in the process of cell division: threonine tyrosine kinase (TTK) and polo-like kinase 1 (PLK1). Inhibiting both enzymes is intended to disrupt the cancer cells’ ability to multiply and survive. According to the company, preclinical studies in animal models have shown that the drug suppressed tumor growth and extended survival, even at low doses. When used in combination with BCL-2 inhibitors—a type of drug commonly prescribed in AML—it showed enhanced effects.

The ongoing trial is structured to gradually increase dosage levels in small patient groups to determine the recommended dose for future studies. BAL0891 is being administered intravenously on days 1 and 8 of a 21-day cycle. In the leukemia subgroup, researchers will follow the same schedule and will monitor for safety, biological activity, and how the drug is processed in the body.

In its announcement, the company said the expansion into blood cancer represents a broader strategy to diversify its pipeline beyond solid tumors. A company spokesperson said that BAL0891 may offer a potential new option for patients with few alternatives and that the company is positioning itself for future development in hematologic malignancies.

Shares of SillaJen rose more than 25 percent in after-hours trading on Monday following the announcements. The stock closed at 2,440 won ($1.72) before jumping to 3,005 won in late trading. As of 8:53 a.m. Tuesday, the stock was trading at 3,015 won, up 23.57 percent from the previous day’s close.