SELLAS Life Sciences Announces Enrollment of First Patient in Newly Diagnosed First-Line AML Trial of SLS009

Rhea-AI Summary

SELLAS (NASDAQ: SLS) enrolled the first patient in a randomized Phase 2 trial of SLS009 (tambiciclib) for newly diagnosed, first-line AML on March 12, 2026. The study will enroll ~80 patients in two cohorts and expects topline data in Q4 2026.

The trial uses SELLAS' predictive biomarker and AI precision‑medicine models, and follows prior r/r AML Phase 2 results where SLS009 plus aza/ven achieved an overall response rate of 33% (40% at the 30mg BIW dose) and median overall survival of 8.8 months at 30mg BIW.

Positive

• First patient enrolled in randomized Phase 2 first-line AML study
• Study sized at ~80 patients across two high‑need cohorts
• Topline data expected Q4 2026
• Prior r/r AML ORR 33% overall; 40% ORR at 30mg BIW
• Median OS 8.8 months at 30mg BIW dose

Negative

• Small planned cohort (~80 patients) may limit subgroup power
• Topline timing depends on enrollment and event rates through Q4 2026
• Efficacy data cited are from r/r AML, not yet shown in first-line setting

News Market Reaction – SLS

-8.21%

28 alerts

-8.21% News Effect

+9.2% Peak Tracked

-3.5% Trough Tracked

-$90M Valuation Impact

$1.00B Market Cap

0.9x Rel. Volume

On the day this news was published, SLS declined 8.21%, reflecting a notable negative market reaction. Argus tracked a peak move of +9.2% during that session. Argus tracked a trough of -3.5% from its starting point during tracking. Our momentum scanner triggered 28 alerts that day, indicating elevated trading interest and price volatility. This price movement removed approximately $90M from the company's valuation, bringing the market cap to $1.00B at that time.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Planned enrollment: 80 patients ORR all evaluable: 33% ORR at 30 mg BIW: 40% +5 more

8 metrics

Planned enrollment 80 patients Newly diagnosed first-line AML Phase 2 trial of SLS009

ORR all evaluable 33% Completed r/r AML Phase 2 trial, all cohorts and doses

ORR at 30 mg BIW 40% Recommended SLS009 dose level in r/r AML Phase 2

ORR AML-MR 44% AML with myelodysplasia-related changes at 30 mg BIW

ORR ASXL1-mutated AML-MR 50% ASXL1-mutated AML-MR at 30 mg BIW

ORR M4/M5 subtypes 50% M4/M5 AML subtypes in r/r AML Phase 2

Median OS 30 mg BIW 8.8 months r/r AML patients with median 1 prior line of therapy

Median OS AML-MR vs BAT 8.9 vs 2.4 months AML-MR patients on SLS009 combo vs best available therapy

Market Reality Check

Price: $5.36 Vol: Volume 6,122,650 is sligh...

normal vol

$5.36 Last Close

Volume Volume 6,122,650 is slightly below 20-day average 6,705,004 (relative volume 0.91x). normal

Technical Shares at $5.48 are trading above the 200-day MA of $2.42 and about 10.75% below the $6.14 52-week high.

Peers on Argus

SLS fell 5.84% while close peers were mixed: ELTX -8.46%, TLSA -4.38%, TNYA -1.3...

1 Up

SLS fell 5.84% while close peers were mixed: ELTX -8.46%, TLSA -4.38%, TNYA -1.3%, CGTX +0.88%, TRDA +3.77%. Momentum scanner only flagged EPRX (+3.12%), indicating a stock-specific move rather than a coordinated sector reaction.

Historical Context

5 past events · Latest: Jan 14 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Jan 14	Clinical expansion deal	Positive	-1.0%	IMPACT-AML agreement to expand SLS009 clinical program into Europe.
Dec 29	Phase 3 trial update	Neutral	+16.7%	REGAL Phase 3 AML trial nearing 80-event final survival analysis trigger.
Dec 07	Positive Phase 2 data	Positive	+4.6%	SLS009 plus AZA/VEN showed strong ORR and survival in r/r AML-MR.
Nov 12	Earnings and pipeline	Neutral	-2.0%	Q3 2025 financials and confirmation of upcoming SLS009 and GPS milestones.
Nov 03	Upcoming data presentation	Neutral	-1.6%	Announcement of future SLS009 AML-MR data presentation at ASH 2025.

Pattern Detected

Recent SLS news, especially on SLS009 and AML programs, often saw modest or mixed price reactions, with some positive clinical updates aligning with gains but several operational updates met with flat or negative moves.

Recent Company History

Over the last few months, SELLAS has steadily advanced its AML pipeline. In Q4 2025, it reported positive Phase 2 SLS009 data in relapsed/refractory AML-MR and prepared for an 80‑patient newly diagnosed AML trial. A pivotal Phase 3 REGAL trial in AML approached its final 80-event analysis, with an update on Dec 29, 2025. The Jan 14, 2026 IMPACT‑AML agreement expanded SLS009 into Europe. Today’s first‑patient enrollment marks execution of those previously outlined plans.

Regulatory & Risk Context

Active S-3 Shelf

Shelf Active

Active S-3 Shelf Registration 2025-10-10

SELLAS has an effective Form S-3 shelf filed on Oct 10, 2025, registering blocks of common stock for resale, including 15,354,331 shares plus additional warrant-convertible shares for selling holders. The shelf supports flexibility in resales via exchanges, OTC trades, block trades, short sales, Rule 144 transactions, and other permitted methods.

Market Pulse Summary

The stock moved -8.2% in the session following this news. A negative reaction despite operational pr...

Analysis

The stock moved -8.2% in the session following this news. A negative reaction despite operational progress fits a pattern where SELLAS news has occasionally met with selling pressure. While the first-line Phase 2 AML trial builds directly on prior SLS009 data showing ORR up to 50% and mOS near 8.9 months, investors may focus on execution timelines or broader dilution and overhang concerns from registered resale shares. Past events have sometimes seen divergence between seemingly constructive clinical updates and short-term price behavior.

Key Terms

cdk9 inhibitor, overall response rate (orr), median overall survival (mos), relapsed/refractory, +4 more

8 terms

cdk9 inhibitor medical

"SLS009 (tambiciclib), a highly selective CDK9 inhibitor in newly diagnosed..."

A CDK9 inhibitor is a drug that blocks the action of the cellular enzyme CDK9, which acts like a control switch for making certain short‑lived proteins that cells need to survive and multiply. For investors, it matters because these drugs are being developed to shut down critical survival pathways in cancers and some viral infections—think of cutting power to a factory assembly line to halt production—which can drive trial results, regulatory decisions, and company value.

overall response rate (orr) medical

"exceeding the pre-specified ORR threshold of 20%, demonstrating strong efficacy..."

Overall response rate (ORR) is the percentage of trial participants whose disease measurably improves—typically tumor shrinkage or disappearance—according to predefined medical criteria. Investors watch ORR because it provides an early, concrete signal of a therapy’s effectiveness and commercial potential, similar to seeing what share of products in a test batch actually work before deciding to back wider production.

median overall survival (mos) medical

"Median overall survival (mOS) of 8.8 months in patients treated with 30mg BIW..."

Median overall survival (mOS) is the length of time from the start of a study or treatment at which half of the patients are still alive and half have died; it describes the central point of survival times in a clinical trial. Investors care because it summarizes a therapy’s real-world benefit in a single, easy-to-compare number—like the midpoint in a race—affecting regulatory approval chances, market demand, pricing power, and a drug’s commercial value.

relapsed/refractory medical

"previously reported positive Phase 2 results in relapsed/refractory (r/r) AML..."

Relapsed/refractory describes a disease, usually cancer, that has returned after treatment (relapsed) or that did not respond to initial therapy (refractory). For investors this signals a high medical need and a defined patient group for new treatments — like a market of cars that won’t start with a standard key — which can affect drug development priorities, trial designs, potential pricing and commercial opportunity.

biomarker medical

"Predictive biomarker cohort: Newly diagnosed patients unlikely to benefit..."

A biomarker is a measurable indicator found in the body, such as in blood or tissues, that provides information about health, disease, or how the body responds to treatment. For investors, biomarkers can signal the potential success or risk of medical products or therapies, influencing the value of related companies and industry trends. They act like signals or clues that help assess the progress of medical advancements and their market impact.

transcriptomics medical

"through our extensive transcriptomics, genomics, and proteomics models..."

Analysis of all the RNA molecules a cell produces, showing which genes are actively being used at a given time—like reading which recipes are being pulled from a cookbook to see what’s actually being cooked. For investors, transcriptomics helps reveal how diseases work, whether a drug is hitting its target, and which patient groups are most likely to benefit, making it a tool for valuing therapies, guiding clinical trials, and spotting diagnostic or therapeutic opportunities.

genomics medical

"through our extensive transcriptomics, genomics, and proteomics models..."

The study of an organism’s complete set of genes and how those genes behave, interact, and influence traits — like reading and interpreting a living organism’s instruction manual. For investors, genomics matters because it drives new drugs, diagnostics and personalized treatments that can create big commercial opportunities or regulatory risks; understanding genomics helps assess a company’s technology edge, market potential and long-term value.

proteomics medical

"through our extensive transcriptomics, genomics, and proteomics models..."

Proteomics is the large-scale study of all the proteins produced by a cell, tissue or organism, like taking a full inventory and watching how the workforce and machines inside a factory behave. For investors, proteomics matters because it helps identify drug targets, disease indicators and responses to treatments—information that can speed development, reduce risk, guide partnerships and reveal new commercial opportunities in biotech and diagnostics.

AI-generated analysis. Not financial advice.

- Study to Enroll 80 Patients Unlikely to Benefit from Venetoclax/Azacitide (Aza/Ven) Therapy in the US and Europe -
- SELLAS’ Predictive Biomarker and AI Assisted Precision Medicine Models to be Utilized -
- Topline Data Expected in Q4 2026 –

NEW YORK, March 12, 2026 (GLOBE NEWSWIRE) -- SELLAS Life Sciences Group, Inc. (NASDAQ: SLS) (“SELLAS” or the “Company”), a late-stage clinical biopharmaceutical company focused on the development of novel therapies for a broad range of cancer indications, today announced the first patient has been enrolled in its randomized Phase 2 trial evaluating SLS009 (tambiciclib), a highly selective CDK9 inhibitor in newly diagnosed, first-line acute myeloid leukemia (AML) patients.

The newly initiated NCT04588922 is designed to enroll approximately 80 patients and includes two AML cohorts with high unmet need and greatest potential benefit:

1. Predictive biomarker cohort: Newly diagnosed patients unlikely to benefit from standard aza/ven therapy based on molecular profiling
   
2. Early resistance cohort: Patients who initiate treatment with aza/ven but demonstrate a confirmed lack of any response after two treatment cycles
   
   

“Enrolling the first patient in this first-line AML Phase 2 study represents an important milestone in the advancement of our SLS009 program and reflects our precision medicine strategy to address challenging subgroups of AML patients through our extensive transcriptomics, genomics, and proteomics models we have established,” said Angelos Stergiou, MD, ScD hc, President and Chief Executive Officer of SELLAS. “The strength of our Phase 2 data in r/r AML, particularly in high-risk molecular subtypes, together with the FDA's guidance, provided a strong foundation for moving into earlier lines of therapy. By targeting molecularly defined subgroups and those demonstrating early non-response, we aim to address a critical need in frontline AML and position SLS009 for potential registrational development.”

This milestone follows the Company’s previously reported positive Phase 2 results in relapsed/refractory (r/r) AML and the FDA’s guidance recommending advancement into a study that includes newly diagnosed AML patients eligible for venectoclax and azacitidine (aza/ven) therapy.

In the completed Phase 2 trial in r/r AML, SLS009 in combination with aza/ven met all endpoints, exceeding the pre-specified ORR threshold of 20%, demonstrating strong efficacy and favorable safety and tolerability with robust anti-tumor activity:

• 33% overall response rate (ORR) in all evaluable patients across all cohorts and dose levels, and 40% ORR for the recommended 30mg BIW dose level.
• ORR of 44% in AML patients with myelodysplasia-related changes (AML-MR) at the 30mg BIW dose
• ORR of 50% in ASXL1-mutated AML-MR at 30 mg BIW dose levels and 50% ORR in M4/M5 subtypes
• Median overall survival (mOS) of 8.8 months in patients treated with 30mg BIW, with a median of 1 prior line of therapy, and mOS of 8.9 months in AML MR patients vs 2.4 months with best available therapy.
  
  

About SELLAS Life Sciences Group, Inc.

SELLAS is a late-stage clinical biopharmaceutical company focused on the development of novel therapeutics for a broad range of cancer indications. SELLAS’ lead product candidate, GPS, is licensed from Memorial Sloan Kettering Cancer Center and targets the WT1 protein, which is present in an array of tumor types. GPS has the potential as a monotherapy and combination with other therapies to address a broad spectrum of hematologic malignancies and solid tumor indications. The Company is also developing SLS009 (tambiciclib) - potentially the first and best-in-class differentiated small molecule CDK9 inhibitor with reduced toxicity and increased potency compared to other CDK9 inhibitors. Data suggests that SLS009 demonstrated a high response rate in AML patients with unfavorable prognostic factors including ASXL1 mutation, commonly associated with poor prognosis in various myeloid diseases. For more information on SELLAS, please visit www.sellaslifesciences.com.

Forward-Looking Statements

This press release contains forward-looking statements. All statements other than statements of historical facts are “forward-looking statements,” including those relating to future events. In some cases, forward-looking statements can be identified by terminology such as “plan,” “expect,” “anticipate,” “may,” “might,” “will,” “should,” “project,” “believe,” “estimate,” “predict,” “potential,” “intend,” or “continue” and other words or terms of similar meaning. These statements include, without limitation, statements related to the GPS clinical development program, including the REGAL study and the timing of future milestones related thereto. These forward-looking statements are based on current plans, objectives, estimates, expectations, and intentions, and inherently involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks and uncertainties with oncology product development and clinical success thereof, the uncertainty of regulatory approval, and other risks and uncertainties affecting SELLAS and its development programs as set forth under the caption “Risk Factors” in SELLAS’ Annual Report on Form 10-K filed on March 20, 2025 and in its other SEC filings. Other risks and uncertainties of which SELLAS is not currently aware may also affect SELLAS’ forward-looking statements and may cause actual results and the timing of events to differ materially from those anticipated. The forward-looking statements herein are made only as of the date hereof. SELLAS undertakes no obligation to update or supplement any forward-looking statements to reflect actual results, new information, future events, changes in its expectations, or other circumstances that exist after the date as of which the forward-looking statements were made.

Investor Contact

John Fraunces
Managing Director
LifeSci Advisors, LLC
jfraunces@lifesciadvisors.com

FAQ

What is the design and size of SELLAS's SLS009 Phase 2 AML trial (SLS)?

The trial is a randomized Phase 2 study enrolling approximately 80 patients in two cohorts. According to the company, cohorts include biomarker‑predicted aza/ven non‑responders and early aza/ven non‑responders, using transcriptomic/genomic/proteomic models to select patients.

When will SELLAS (SLS) report topline results for the SLS009 first‑line AML study?

Topline data are expected in Q4 2026. According to the company, reporting timing depends on enrollment pace and predefined endpoints being reached during the trial's conduct.

What prior clinical evidence supports SELLAS moving SLS009 into first‑line AML (SLS)?

Prior Phase 2 in relapsed/refractory AML showed a 33% ORR overall and 40% ORR at the 30mg BIW dose. According to the company, those results and FDA guidance supported advancing into newly diagnosed patients.

Which patient groups will SELLAS target in the SLS009 first‑line AML trial (SLS)?

The study targets newly diagnosed patients unlikely to benefit from aza/ven and patients with confirmed early non‑response to aza/ven. According to the company, biomarker and AI models will guide enrollment into these two high‑need cohorts.

How did SLS009 perform on survival outcomes in prior trials relevant to SELLAS investors (SLS)?

At the 30mg BIW dose, median overall survival was reported as 8.8 months. According to the company, mOS at 30mg BIW compared favorably versus best available therapy in the cited r/r AML dataset.