Sumitomo Pharma Oncology Presents Preliminary Data from Phase 1/2 Clinical Study Evaluating Investigational Agent TP-3654 in Patients with Myelofibrosis at American Society of Hematology 2022 Annual Meeting & Exposition

CAMBRIDGE, Mass., Dec. 10, 2022 /PRNewswire/ -- Sumitomo Pharma Oncology, Inc., a clinical-stage company focused on novel cancer therapeutics, today presented new data from the ongoing Phase 1/2 study evaluating TP-3654, an investigational selective oral PIM1 kinase inhibitor, in patients with myelofibrosis (MF) previously treated with or ineligible for JAK inhibitor therapy. These results were presented during an oral presentation at the American Society of Hematology (ASH) Annual Meeting & Exposition, being held Dec 10-13, 2022, in New Orleans, LA.

Preliminary findings from the Phase 1 dose escalation study indicated TP-3654 is well tolerated with limited myelosuppressive adverse events. TP-3654, as a single agent, showed preliminary signs of clinical activity in the study, including spleen volume reduction, symptom improvement, and broad cytokine reduction, in patients previously treated with JAK inhibitors.¹

"We are pleased by these preliminary clinical data and are encouraged by the safety and tolerability data seen in the ongoing TP-3654 dose escalation study. We remain committed to progressing this program, including expanding our clinical sites, and contributing to the advancement of possible treatment options which may improve outcomes for patients with myelofibrosis," said Patricia S. Andrews, Chief Executive Officer and Global Head of Oncology, Sumitomo Pharma Oncology, Inc.

The dose escalation portion of the study has enrolled 9 patients at the time of the analysis. To date, five dose levels of TP-3654 were evaluated, including once-daily and twice-daily regiments. No dose-limitation or related serious adverse event was observed up to the time of the analysis.

The data showed an early signal of clinical activity with spleen volume reduction (SVR). Six of 8 evaluable patients on treatment for at least 12 weeks experienced SVR, including 2 of 8 patients having at least 35% SVR. Additionally, a reduction in the symptom burden, measured by change in treatment score symptom (TSS), was experienced by 7 of the 8 evaluable patients, with 5 out of 8 patients having greater than 50% reduction. TP-3654 treatment was associated with reduced levels of cytokines associated with MF as early as 4 weeks, with cytokine reductions correlating with improved TSS.

Overall, TP-3654 appears to be well tolerated with no dose limiting toxicity (DLT) to date. The most common adverse events are Grade 1 gastrointestinal toxicities, which resolved in 1-2 weeks. Additionally, patients showed stable blood counts and no cytopenia with extended time on treatment. Currently, there are no discontinuations due to adverse events.

"These preliminary data presented at ASH 2022 Annual Meeting & Exhibition are encouraging as we learn more about how TP-3654's inhibition of PIM1 kinase may lead to reductions in bone marrow fibrosis and splenomegaly, and improved overall survival in patients with myelofibrosis," said Jatin J. Shah, M.D., Chief Medical Officer and Global Head of Development, Sumitomo Pharma Oncology (SMP Oncology). "We look forward to continuing to advance this study to evaluate the potential role of TP-3654 as a monotherapy, in addition to exploring combination opportunities with JAK inhibitors, for patients with myelofibrosis." Below are the details for the SMP Oncology presentation:

To view the full presentation, please visit to our website here.

TP-3654 is an oral investigational inhibitor of PIM kinases, which has shown potential antitumor and anti-fibrotic activity through multiple pathways, including induction of apoptosis in preclinical models.^2,3 TP-3654 was observed to inhibit proliferation and increased apoptosis in murine and human hematopoietic cells expressing clinically relevant JAK2V617F mutation.³ TP-3654 alone and in combination with ruxolitinib also showed normalized WBC and neutrophil counts, and reduced spleen size and bone marrow fibrosis in JAK2V617F and MPLW515L murine models of myelofibrosis.³ TP-3654 is currently being evaluated in a Phase 1/2 study of oral TP-3654 in patients with intermediate and high-risk myelofibrosis (NCT04176198).

Sumitomo Pharma Oncology, Inc. is a wholly owned subsidiary of Sumitomo Pharma Co., Ltd. As a global oncology organization with teams in the U.S. and Japan, SMP Oncology is committed to the goal of advancing purposeful science by transforming new discoveries into meaningful treatments for patients with cancer. SMP Oncology's robust and diverse pipeline of preclinical and clinical-stage assets spans multiple areas, including oncogenic pathways, survival mechanisms and novel protein interactions, which aim to address unmet clinical needs in oncology. For more information, visit www.oncology.sumitomo-pharma.com.

Sumitomo Pharma Co., Ltd. is among the top-ten listed pharmaceutical companies in Japan, operating globally in major pharmaceutical markets, including Japan, the U.S., China, and other Asian countries with about 7,000 employees worldwide. Sumitomo Pharma Co., Ltd. defines its corporate mission as "To broadly contribute to society through value creation based on innovative research and development activities for the betterment of healthcare and fuller lives of people worldwide." Additional information about Sumitomo Pharma Co., Ltd. is available through its corporate website at https://www.sumitomo-pharma.com.

This press release contains "forward-looking statements," as that term is defined in the Private Securities Litigation Reform Act of 1995 regarding the research, development, and commercialization of pharmaceutical products. The forward-looking statements in this press release are based on management's assumptions and beliefs in light of information presently available and involve both known and unknown risks and uncertainties. Any forward-looking statements set forth in this press release speak only as of the date of this press release. We do not undertake to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. Information concerning pharmaceuticals (including compounds under development) contained within this material is not intended as advertising or medical advice.

1. Firas El Chaer, MD, James McCloskey, MD, et al. Preliminary Data from the Phase I/II Study of TP-3654, a Selective Oral PIM1 Kinase Inhibitor, in Patients with Myelofibrosis Previously Treated with or Ineligible for JAK Inhibitor Therapy. American Society of Hematology (ASH) 2022 Annual Meeting & Exhibition. 10 December 2022.
2. Foulks JM, Carpenter KJ, Luo B, et al. A small-molecule inhibitor of PIM kinases as a potential treatment for urothelial carcinomas. Neoplasia. 2014;16(5):403-412.
3. Nath D, Yang Y, Dutta A, Whatcott C. The PIM kinase inhibitor TP-3654 in combination with ruxolitinib exhibits marked improvement of myelofibrosis in murine models. Blood. 2018. 132(suppl 1):54. doi:10.1182/blood-2018-99-119421

SOURCE Sumitomo Pharma Oncology, Inc.