SLS Stock Rises Premarket Ahead Of Cancer Summit This Month – Investors Eye Phase 3 AML Trial Milestone

• Sellas will present new data on its CDK9 inhibitor SLS009 at the American Association for Cancer Research (AACR) meeting on April 21.
• Preclinical findings showed SLS009 triggered leukemia cell death by increasing caspase-3 activity and reducing survival proteins such as MCL-1 and survivin.
• Investor focus remains centered on the Phase 3 Regal study evaluating GPS as a maintenance therapy for AML patients in remission after relapse.

Shares of Sellas Life Sciences Group, Inc. (SLS) rose 1% in premarket trading on Thursday as investors positioned ahead of an upcoming cancer conference presentation and a closely watched survival milestone in the company’s Phase 3 acute myeloid leukemia (AML) trial.

SLS stock jumped 8% on Wednesday amid a volatile trading week.

AACR Preview: SLS009 Triggers Leukemia Cell Death Signals

Sellas is preparing to present new preclinical data on its CDK9 inhibitor candidate SLS009 at the American Association for Cancer Research (AACR) annual meeting on April 21 in San Diego.

Preclinical findings showed that SLS009 triggered leukemia cell death by increasing the activity of caspase-3, a key apoptosis protein, while lowering survival signals such as MCL-1 and survivin that help cancer cells persist. The drug also became more potent with repeated exposure, with early effects appearing within hours and strengthening over 24 hours.

Notably, SLS009 remained active even in AML models carrying ASXL1 and TP53 mutations, which are associated with treatment resistance and poorer outcomes.

Investor Focus Remains On AML Survival Readout Timeline

However, investor attention remains firmly focused on the company’s Phase 3 Regal trial evaluating GPS as a maintenance therapy for AML patients whose disease returned but later entered remission following additional treatment.

GPS targets the Wilms Tumor-1 antigen, a protein commonly expressed across leukemia cells regardless of mutation status.

The event-driven study will begin final analysis once 80 overall-survival events are recorded. Sellas previously said the contract research organization monitoring the trial had logged 72 events as of Dec. 26, bringing the study closer to the threshold required to initiate topline analysis.

CEO Angelos Stergiou recently addressed speculation surrounding the timing of the readout on LinkedIn, noting that slower accumulation of survival events in oncology trials can sometimes indicate patients are living longer than baseline expectations.

Once the 80th event occurs, the company plans to proceed with database lock, statistical analysis, unblinding and disclosure of topline results.

How Does Retail Feel About SLS?

On Stocktwits, retail sentiment for SLS has slipped to ‘bearish’ from ‘extremely bullish’ levels a month ago amid a 23% dip in message volumes over the past week.

One user said SLS is “truly shaping up to be a once in a lifetime moonshot win.  Don't miss your chance.”

Another user said, “GPS is a safe harbour now, the IDMC meeting will reveal this. We should be worth 2B Dollar already.”

SLS stock has surged 367% over the past year.

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