What SELLAS Life Sciences does

SELLAS Life Sciences Group, Inc. is a late-stage clinical biopharmaceutical company headquartered at 7 Times Square in New York City, listed on NASDAQ under the ticker SLS. The company develops novel therapeutics for a broad range of cancer indications, with a pipeline built around two core clinical-stage candidates: galinpepimut-S (GPS), a multi-peptide cancer immunotherapeutic that targets the Wilms tumor 1 (WT1) protein using AI-designed heteroclitic peptides, and SLS009 (tambiciclib), a highly selective cyclin-dependent kinase 9 (CDK9) inhibitor that induces apoptosis via MCL-1 and c-MYC suppression. GPS is licensed globally from Memorial Sloan Kettering Cancer Center, and SLS009 is licensed from GenFleet Therapeutics for territories outside Greater China. A third asset, GPS+ (nelipepimut-S), sits at the preclinical stage.

The company is pre-revenue and operates a traditional biotech go-to-market model centered on clinical development, regulatory engagement (GPS has received FDA Fast Track Designation for AML in CR2), and partnership-based commercialization. The lead program GPS is being evaluated in the Phase 3 REGAL trial in acute myeloid leukemia, which reached 78 of 80 required events as of May 11, 2026, positioning the company for a near-term pivotal readout. SLS009 is advancing through Phase 2 development in relapsed/refractory and first-line AML. Geographic commercialization rights are largely externalized through licensing agreements — 3D Medicines holds Greater China rights to GPS and GPS+, while SELLAS retains rights in all other territories — creating an asset-light path to international reach. The company is led by founder, President and CEO Angelos M. Stergiou, MD, with a management team spanning clinical development, regulatory affairs, finance, and commercial functions. With $107.1 million in cash as of March 31, 2026, plus additional Q2 2026 warrant proceeds, and a market valuation exceeding $1.5 billion as of May 2026, SELLAS is capitalized to advance its pipeline through the Phase 3 readout and into potential commercial launch.

Name

SELLAS Life Sciences

Legal name

SELLAS Life Sciences Group, Inc.

Website

https://sellaslifesciences.com

Company type

Public

Founded year

2006

Operating status

Operating

Headcount range

11–50 employees

Short description

SELLAS Life Sciences is a late-stage clinical biopharmaceutical company developing novel cancer therapies, principally GPS (a WT1-targeting immunotherapeutic licensed from MSKCC) and SLS009 (a CDK9 inhibitor licensed from GenFleet). The company serves oncology patients with hematologic malignancies and solid tumors and is approaching a pivotal Phase 3 readout in AML.

Ownership category

akta.pro rank

Product category

Clinical-stage oncology biopharmaceuticals

NAICS

Biological Product (except Diagnostic) Manufacturing (325414)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Oncology & Hematology Pharmaceuticals (HLAIAAAC)

akta.pro secondary industries

Therapeutic Vaccines (cancer, chronic infection immunotherapy) (HLAAAEAB), Rare Oncology & Hematologic Malignancy Therapies (HLAIAIAC)

Keywords

• Cancer immunotherapy
• Clinical biopharmaceuticals
• CDK9 inhibitor
• WT1 targeted therapy
• Hematologic oncology

Headquarters

HQ city

New York

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales

Revenue model

1. Product Revenue (Future): SELLAS is a pre-revenue clinical-stage biopharmaceutical company with no commercialized products. The company is focused on developing novel cancer therapies through clinical trials toward regulatory approval. Revenue will be generated from product sales upon successful commercialization of GPS, SLS009, or other pipeline candidates.
2. Licensing Revenue: The company has entered into licensing agreements that may generate future milestone payments and royalties. This includes licensing agreements with 3D Medicines for Greater China territory and retention of rights outside Greater China for GPS and GPS+, and licensing arrangements for SLS009 outside Greater China with GenFleet Therapeutics.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

SELLAS is a late-stage clinical biopharmaceutical company that develops novel cancer therapeutics. Its core product candidates are galinpepimut-S (GPS), a WT1-targeting multi-peptide cancer immunotherapeutic licensed from Memorial Sloan Kettering Cancer Center, and SLS009, a highly selective small-molecule CDK9 inhibitor licensed from GenFleet Therapeutics. The pipeline additionally includes GPS+, a next-generation heptavalent WT1 immunotherapeutic currently at the preclinical stage.

Product overview

SELLAS Life Sciences is a late-stage clinical biopharmaceutical company focused on novel cancer therapies. The company's product portfolio consists of two core clinical-stage candidates: Galinpepimut-S (GPS), a WT1-targeting cancer immunotherapeutic that activates T-cell immune responses against WT1-positive cancer cells, and SLS009, a highly selective CDK9 inhibitor that induces cancer cell apoptosis through MCL-1 and MYC suppression. Additionally, GPS+ represents a next-generation heptavalent immunotherapeutic in preclinical development. GPS is licensed globally from Memorial Sloan Kettering Cancer Center, while SLS009 is licensed from GenFleet Therapeutics for territories outside Greater China.

Differentiator

Problem solved

Functional benefit

Products and services

• Galinpepimut-S (GPS) A multi-peptide cancer immunotherapeutic targeting the Wilms Tumor 1 (WT1) protein. It contains four heteroclitic peptides (two with single amino acid mutations designed using artificial intelligence) that activate CD4 and CD8 T-cell responses against WT1-expressing cancer cells while sparing normal cells. Designed for use as maintenance therapy to prevent relapse in patients with WT1-positive hematologic malignancies and solid tumors, including acute myeloid leukemia (AML), multiple myeloma, malignant pleural mesothelioma, ovarian cancer, and peripheral T-cell lymphoma.
• SLS009 (tambiciclib) A next-generation highly selective small-molecule cyclin-dependent kinase 9 (CDK9) inhibitor that decreases MCL-1 and c-MYC protein levels, inducing apoptosis and cell cycle arrest in cancer cells. Designed to address resistance to venetoclax-based therapies by targeting MCL-1, a dominant survival mechanism after venetoclax failure. Demonstrated enhanced potency with repeated exposure (IC50 reduced from approximately 50 nM to 20 nM) and improved specificity versus first-generation CDK9 inhibitors, with the potential for reduced toxicity. Indicated for relapsed/refractory acute myeloid leukemia and other hematologic malignancies.
• GPS+ (Nelipepimut-S) A next-generation heptavalent WT1-targeting immunotherapeutic designed to expand upon the GPS platform. Currently at the preclinical development stage, intended for treatment of cancers expressing the WT1 protein across multiple indications.

Quantifiable outcome

• Median OS of 21 months for GPS vs 5.4 months for standard care in AML CR2 patients (p<0.02)
• +4 more outcomes

Segments2 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability1 record

Feature3 records

Partnerships

Three partnerships are on record, tiered core and flagship.

• GenFleet Therapeutics (Shanghai), Inc.coreStrategic or Co-development Partner · 1 March 2022In March 2022, SELLAS entered into an exclusive license agreement with GenFleet Therapeutics for the development and commercialization of SLS009, a highly selective CDK9 inhibitor, across all therapeutic and diagnostic uses worldwide outside of the Greater China Region.
• 3D Medicines, Inc.coreStrategic or Co-development Partner · 1 December 2020In December 2020, SELLAS entered into an exclusive license agreement with 3D Medicines Inc., a China-based biopharmaceutical company, for the development and commercialization of GPS and next-generation heptavalent immunotherapeutic GPS+ across all therapeutic and diagnostic uses in Greater China territory (mainland China, Hong Kong, Macau and Taiwan). SELLAS retained sole rights to GPS and GPS+ outside of Greater China.
• Memorial Sloan Kettering Cancer Center (MSKCC)flagshipStrategic or Co-development Partner · 1 September 2014In September 2014, SELLAS announced an exclusive global collaboration and exclusive license agreement with MSKCC for the development, marketing and commercialization of MSKCC's proprietary WT1 cancer immunotherapy, galinpepimut-S (GPS). This is SELLAS's core partnership for its lead product candidate.

Scale indicators8 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Geron Corporation: Late-stage hematology-focused biopharma developing imetelstat for lower-risk MDS and AML. Comparable to SELLAS as a small-cap, late-stage oncology company with a single pivotal hematologic asset and limited commercial footprint.
• TG Therapeutics: Commercial and late-stage hematology/oncology company with approved hematologic assets and an active pipeline. Comparable as a small-cap public biopharma operating in hematologic malignancies with similar regulatory and commercial dynamics.
• Cogent Biosciences: Late-stage precision oncology company developing kinase inhibitors in hematologic malignancies. Comparable to SELLAS in stage (Phase 2/3), kinase-focused mechanism (overlapping with SLS009 CDK9), and small-cap public profile.
• Syros Pharmaceuticals: Clinical-stage biopharma focused on heme malignancies, including AML and MDS, with small-molecule and gene-control approaches. Comparable in indication focus (AML/MDS), small-cap public profile, and reliance on a small set of clinical assets.
• Aprea Therapeutics: Clinical-stage oncology company developing small-molecule therapies for cancer, including hematologic malignancies. Comparable as a small-cap, late-clinical-stage public biopharma targeting oncology indications with limited commercial infrastructure.
• Kronos Bio: Clinical-stage oncology company developing CDK9 and other targeted therapies in hematologic malignancies. Directly comparable to SLS009 on CDK9 mechanism and AML/ALL patient populations.

Broad incumbents

• AbbVie: Large oncology biopharma with venetoclax (Venclexta) in AML — the backbone of combinations SLS009 is being tested with. Relevant as the dominant incumbent in venetoclax-based AML regimens and a potential combination or commercialization partner.
• Bristol Myers Squibb: Major oncology biopharma with established AML and hematology franchises (e.g., azacitidine, cytarabine combinations). Comparable as a broad incumbent operating in the same indications where SELLAS is testing its pipeline.
• Jazz Pharmaceuticals: Established biopharma with a significant hematology/oncology franchise including AML therapies (e.g., Vyxeos). Comparable as a broader incumbent with overlapping AML patient populations and commercial channels.
• Astex Pharmaceuticals (Otsuka): Cancer therapeutics developer and CDK inhibitor originator (with drugs like decitabine/cedazuridine and earlier CDK programs). Comparable as an established player with kinase-inhibitor expertise overlapping SLS009's CDK9 mechanism.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/sellas-life-sciences

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Funding overview

Funding rounds9 records

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about SELLAS Life Sciences