SELLAS Life Sciences Group (SLS) investor relations material

Executive summary

• SLS009 showed positive Phase 2 results in relapsed/refractory AML, meeting all primary endpoints with a 44% response rate in AML-MRC and median overall survival of 8.9 months, nearly tripling historical benchmarks; FDA guidance received to advance to first-line AML trial by Q1 2026.

• REGAL Phase 3 trial for GPS in AML is ongoing, with interim analysis completed and a positive IDMC recommendation to continue; final analysis expected by year-end 2025.

• Expanded Scientific Advisory Board with oncology experts and presented promising preclinical data for SLS009 in ASXL1-mutated colorectal cancer and T-PLL.

• No product sales revenue; licensing revenue only from 3D Medicines Agreement, with ongoing arbitration over milestone payments.

• Inclusion in the Russell 3000 and Russell 2000 indexes, enhancing market visibility.

Financial highlights

• Net loss for Q2 2025 was $6.6 million ($0.07 per share), improved from $7.5 million ($0.13 per share) in Q2 2024; net loss for the first half of 2025 was $12.4 million ($0.13 per share), down from $17.0 million ($0.33 per share) prior year.

• R&D expenses for Q2 2025 were $3.9 million, down from $5.2 million in Q2 2024, mainly due to completion of REGAL study enrollment; first half 2025 R&D expenses were $7.1 million, down from $10.3 million year-over-year.

• G&A expenses for Q2 2025 were $3.0 million, up from $2.4 million in Q2 2024; first half 2025 G&A expenses were $5.9 million, down from $7.0 million year-over-year.

• Cash and cash equivalents were $25.3 million as of June 30, 2025, up from $13.9 million at year-end 2024, with an additional $4.0 million received in July 2025 from warrant exercises.

• No revenue recognized in the quarter; $191.5 million in potential future milestones under the 3D Medicines Agreement remain.

Outlook and guidance

• Cash and cash equivalents are not sufficient to fund planned operations for the next twelve months; substantial doubt exists about ability to continue as a going concern.

• Additional financing will be required to support ongoing development and operations; management is evaluating funding strategies.

• Research and development expenses expected to increase as GPS approaches potential BLA filing and SLS009 advances to first-line AML trial.

• Final analysis of the Phase 3 REGAL trial of GPS in AML expected by year-end 2025.

• Enrollment for the first-line SLS009 AML trial anticipated to begin by Q1 2026.