SELLAS Life Sciences Group (SLS) investor relations material

Company overview and strategy

• Focuses on late-stage oncology with two main assets: GPS (galinpepimut-S) and SLS-009, both targeting acute myeloid leukemia (AML).

• GPS is a WT1-targeting immunotherapy in phase III (REGAL trial) for AML maintenance after second remission.

• SLS-009 is a selective CDK9 inhibitor in phase II for frontline AML and other cancers.

• Uses precision medicine approaches, leveraging transcriptomics, genomics, and proteomics to identify responsive patients.

• Aims to shift AML treatment from induction to maintenance, positioning as a leader in targeted cancer therapeutics.

GPS (galinpepimut-S) clinical progress and potential

• REGAL phase III trial in AML is nearing completion, with 78 of 80 required events (deaths) reached; unblinding and top-line data expected soon.

• GPS has shown positive trends in overall survival and durable immune responses, with a favorable safety profile across multiple cancers.

• If successful, GPS could become the first approved maintenance therapy for AML in the CR2 setting, with potential expansion to CR1 and other WT1-expressing cancers.

• Targets the WT1 antigen, expressed in about 20 tumor types, opening opportunities for broader indications.

• Fast Track and Orphan Drug designations may expedite regulatory review.

SLS-009 (CDK9 inhibitor) development and data

• SLS-009 is highly selective for CDK9, minimizing toxicity seen with other inhibitors and allowing higher dosing.

• Phase II expansion study showed a 44% overall response rate in relapsed/refractory AML-MR, and 58% in patients with one prior therapy, surpassing benchmarks.

• Median overall survival in venetoclax-refractory patients was 8.9 months, far exceeding historical 2.4 months.

• Current trial, with FDA input, is enrolling newly diagnosed AML patients and those refractory to standard therapy, using biomarker-driven selection.

• Top-line data from the ongoing study expected by year-end, with potential for accelerated approval or rapid progression to registrational trials.