SELLAS Life Sciences Group, Inc.

What they do

SELLAS develops GPS, a peptide immunotherapy licensed from Memorial Sloan Kettering Cancer Center that targets the WT1 antigen present in 20 or more cancer types, and SLS009 (tambiciclib), a selective CDK9 inhibitor licensed from GenFleet Therapeutics for worldwide rights excluding Greater China. GPS is in an ongoing open-label randomized Phase 3 REGAL trial as monotherapy in AML patients in second complete remission, with overall survival as the primary endpoint. SLS009 is in a Phase 2 trial in newly diagnosed AML in combination with azacitidine and venetoclax, and has shown preclinical activity in pancreatic ductal adenocarcinoma.

Revenue drivers

• GPS (galinpepimut-S) — Lead product candidate; no product revenue to date. Under the 3D Medicines license for Greater China, SELLAS has received $10.5 million in aggregate upfront and milestone payments as of December 31, 2025, with up to $191.5 million in potential future development, regulatory and sales milestones plus royalties.
• SLS009 (tambiciclib) — Second product candidate licensed from GenFleet for worldwide rights excluding Greater China; no revenue reported in the filings.
• License and milestone payments — The only reported revenue history is milestone-based: annual revenue was $1.9 million in 2020, $7.6 million in 2021, $1.0 million in 2022, and $0.00 in 2019 and 2023. Recent quarterly revenue was $0.00 throughout 2023.

Recent performance

For the second quarter of 2026, SELLAS reported a net loss of $9.6 million, or $0.05 per basic and diluted share, compared with a net loss of $6.6 million, or $0.07 per share, in the second quarter of 2025. First-half 2026 net loss was $18.0 million, or $0.10 per share, versus $12.4 million, or $0.13 per share, in the first half of 2025. R&D expenses were $6.3 million in Q2 2026 versus $3.9 million in Q2 2025, and G&A was $4.4 million versus $3.0 million, with increases attributed to manufacturing, clinical and regulatory consulting, and preparation for a potential GPS BLA. Cash and cash equivalents totaled approximately $138.3 million as of June 30, 2026. The company reported no product revenue.

Strategy

Management is advancing GPS toward the pre-specified 80th event in the Phase 3 REGAL trial, which would trigger database lock, blinded data review, unblinding, and topline disclosure, with the goal of a potential BLA submission if results are statistically significant and clinically meaningful. For SLS009, the company is enrolling and dosing an 80-patient Phase 2 trial in newly diagnosed AML, including patients refractory early to azacitidine/venetoclax, with topline data expected in Q4 2026. SELLAS also reported preclinical results suggesting SLS009 can act as a single agent in pancreatic ductal adenocarcinoma cells resistant to leading RAS inhibitors and synergize with RAS inhibition, and intends to support clinical development at a top-tier academic institution. The company states it remains blinded to all efficacy and survival data outcomes.

Risks

• No product revenue or profitability — The company reports no source of product revenues, has incurred substantial losses since inception, and expects continued and increasing losses.
• Dependence on REGAL trial outcome — GPS's path to a BLA depends on a statistically significant and clinically meaningful overall survival result at the final analysis, which is event-driven and difficult to predict.
• Need for additional financing — Management states it will need additional financing to fund operations and complete development and potential commercialization, and failure to raise capital could force delays or elimination of programs.
• Reliance on third parties and licenses — SELLAS depends on CROs, CMOs and in-licensed intellectual property from MSK and GenFleet; a breach of either license agreement could end development of GPS or SLS009.

Outlook

Management said the final analysis of the Phase 3 REGAL trial will be conducted once 80 events occur, and the company will announce when the required 80th event is reached, which will trigger database lock, review procedures, unblinding, and disclosure of topline results. Topline data from the ongoing 80-patient Phase 2 trial of SLS009 in newly diagnosed first-line AML are expected in Q4 2026. SELLAS also intends to pursue clinical development of SLS009 in pancreatic ductal adenocarcinoma at a top-tier academic institution following preclinical results.