SELLAS Reports Positive Phase 2a Trial Results for SLS009 and Zanubrutinib in DLBCL

SELLAS Life Sciences Group, Inc., a biopharmaceutical company concentrating on advanced-stage clinical development, recently shared promising results from its Phase 2a trial of SLS009 (tambiciclib). This trial involved patients with relapsed or refractory Diffuse Large B-Cell Lymphoma (r/r DLBCL) and was undertaken by GenFleet Therapeutics in China. The study assessed the efficacy of SLS009, a selective CDK9 inhibitor, in conjunction with the BTK inhibitor Brukinsa® (zanubrutinib).

Key findings from this open-label, single-arm multicenter study reveal a significant improvement in patient outcomes. Notably, the combination therapy achieved an overall response rate (ORR) of 67%, surpassing the anticipated efficacy of zanubrutinib on its own. Among the participants, one patient reached a complete response, while three others experienced partial responses with notable reductions in tumor size. Despite a median follow-up period of 4.6 months, the median overall survival has yet to be determined, with six out of the nine patients still alive, indicating the potential long-term benefits of this treatment approach.

Dr. Angelos Stergiou, President and CEO of SELLAS, emphasized the importance of these findings, noting that the results highlight the potential of combining SLS009 with zanubrutinib to enhance treatment outcomes for DLBCL patients. He expressed hope that this combination therapy could lead to more innovative and effective treatments for this challenging cancer type.

The trial involved nine patients diagnosed with r/r DLBCL, including six with the more aggressive activated B-cell like (ABC) subtype, also known as non-GCB DLBCL. This subtype typically presents a poorer prognosis compared to the germinal center B-cell like (GCB) subtype. Among the six non-GCB DLBCL patients, four showed objective responses, and one had stable disease, resulting in a disease control rate of 83%.

Genetic analysis of the participants revealed no MYD88 or CD79B mutations, which are commonly linked with better responses to BTK inhibitors. Interestingly, the patient who achieved a complete response exhibited MYC amplification alongside TP53 mutations, suggesting that SLS009’s CDK9 inhibition may offer a way to overcome drug resistance in cancers with TP53 mutations.

Dr. Dragan Cicic, Chief Development Officer at SELLAS, highlighted the broader implications of these findings, noting that the data not only support the effectiveness of SLS009 in DLBCL but also reinforce its potential across various cancer types. SELLAS is concurrently advancing clinical developments in acute myeloid leukemia (AML) and exploring other indications to pinpoint genetic biomarkers critical in drug development.

SELLAS Life Sciences is committed to innovating cancer therapies, and its lead candidate, GPS, targets the WT1 protein, prevalent in numerous tumors. GPS is being developed as both a monotherapy and in combination with other treatments to address a wide range of hematological and solid tumors. Meanwhile, SLS009, known for its reduced toxicity and increased potency compared to other CDK9 inhibitors, continues to show promise in treating cancers with adverse prognostic factors.

Overall, the Phase 2a trial's outcomes underscore the potential for combination therapies in enhancing cancer treatment efficacy, particularly for patients with difficult-to-treat DLBCL. SELLAS remains focused on pushing the boundaries of cancer treatment through strategic collaborations and innovative research.