FDA Grants Orphan Drug Designation to JBI-802 for Small Cell Lung Cancer and AML

The FDA has granted an orphan drug designation to JBI-802 for the treatment of patients with small cell lung cancer (SCLC) and acute myeloid leukemia (AML), according to an announcement from Jubilant Therapeutics, Inc.¹

The agent is currently under evaluation in a phase 1/2 trial (NCT05268666) in patients with advanced solid tumors.

“JBI-802 is the lead product candidate from our TIBEO [Therapeutic Index and Brain Exposure Optimization] Discovery Engine,” Syed Kazmi, chief executive officer of Jubilant Therapeutics Inc, stated in a press release. “It is our unique approach of structure-based drug design to generate novel pharmacophores with improved target product profile compared to existing agents.”

JBI-802 is a dual LSD1- and HDAC6-directed epigenetic modulator engineered in a single pharmacophore to inhibit the transcriptional regulator CoREST, which regulates the development of cellular lineages responsible for neuroendocrine tumors like SCLC and hematopoietic tumors like AML.

Previously, the LSD1-only inhibitor, bomedemstat (IMG-7289), reported positive clinical findings in patients with essential thrombocythemia, supporting the role of epigenetic modulators in hematologic malignancies.

Moreover, preclinical research has shown synergistic antitumor activity with JBI-802 compared with inhibitors directed toward either target alone. The agent has also been found to have a favorable safety profile with no significant safety concerns. As such, JBI-802 is expected to be more tolerable than first-generation, single-target epigenetic modulators.

“The orphan drug designations were supported by several relevant preclinical models. In SCLC, JBI-802 showed unique activity not just in normal neuroendocrine models but also in the ‘variant’ models driven by MYC amplification. [These] data also support the ongoing phase 1/2 clinical trial in neuroendocrine tumor patients,” Kazmi explained. “In AML, the activity was uniquely seen in models of erythroleukemia, a subset of leukemia, with a unique erythroid phenotype and a very high unmet need based on its aggressive nature and limited therapy.”

In January 2022, the FDA cleared the investigational new drug application for JBI-806 for the treatment of SCLC, treatment-induced neuroendocrine prostate cancer, and other mutation-defined neuroendocrine tumors.²

In April 2022, the first patient had been dosed in the open-label, two-part dose-escalation and -expansion phase 1/2 trial.³ The study population comprised patients with locally advanced or metastatic solid tumors whose disease has progressed on prior standard therapy. Planned expansion cohorts will consist of patients with SCLC, NEPC, and other neuroendocrine-derived cancers, with a goal to expand into hematologic malignancies such as AML, essential thrombocythemia, and other myeloproliferative neoplasms (MPNs).

“This designation and emerging clinical data from the ongoing first-in-human JBI-802 study will now underpin expansion of our clinical activities in thrombocythemia, leukemia and other erythroid tumors like MPNs,” Kazmi concluded.

References

1. Jubilant Therapeutics Inc. receives orphan drug designation for JBI-802 for acute myeloid leukemia (AML) and small cell lung cancer (SCLC). News release. Jubilant Therapeutics, Inc. January 5, 2023. Accessed January 16, 2023. https://prn.to/3XgYGKr
2. Jubilant Therapeutics announces FDA clearance of IND for JBI-802, a novel dual LSD1 and HDAC6 inhibitor, for treatment of solid tumors. News release. Jubilant Therapeutics, Inc. January 6, 2022. Accessed January 16, 2023. https://prn.to/3XxgOj9
3. Jubilant Therapeutics Inc. doses first patient in phase I/II trial evaluating JBI-802, dual inhibitor of LSD1 and HDAC6, in patients with advanced solid tumors. News release. Jubilant Therapeutics, Inc. April 26, 2022. Accessed January 16, 2023. https://prn.to/3IRQHzp