SLS Stock’s Big AML Trial Milestone Sparks A Selloff — What’s Fueling Retail’s ‘Extremely Bullish’ Bets?

Retail bulls discussed buying the dip and a potential buyout, while others also challenged survival estimates.

• Sellas’ Phase 3 Regal leukemia trial reached its 80th event, triggering final analysis.
• Preliminary topline results are due this quarter, with no survival-benefit findings disclosed yet.
• Sellas also expects fourth-quarter data from its Phase 2 SLS009 study in newly diagnosed AML.

Sellas Life Sciences (SLS) moved closer to a key cancer-drug readout Wednesday, but its shares tumbled nearly 15%, leaving retail bulls buying the dip and betting the upcoming results could reverse the slide.

SLS stock ended 15% lower on Wednesday at $10.38, logging its worst day in nearly five months. Shares are also down 10% for the week. 

Sellas' Countdown To Cancer-Drug Data Begins

Sellas said its Phase 3 Regal trial of Galinpepimut-S (GPS) reached the pre-specified 80th event, meaning 80 deaths had occurred in the study. That threshold triggers the final analysis, with preliminary topline results due this quarter.

Sellas will now lock the database, unblind the data, and analyze the results under its pre-specified statistical plan. However, the update did not reveal whether GPS improved survival. Regal evaluates GPS as a maintenance treatment for patients with acute myeloid leukemia (AML) who have achieved a second complete remission. Overall survival is the primary endpoint, with leukemia-free survival as a secondary measure.

“With this pivotal study now advancing to final analysis, we look forward to evaluating the data, as positive results could position GPS as the first- and best-in-class novel immunotherapeutic option for these patients,” CEO Angelos Stergiou said.

The milestone follows a lengthy wait. Sellas reported 72 events as of Dec. 26, 2025, and 78 as of May 11, 2026. Those pooled counts do not show which treatment arm patients were in or establish whether GPS improved survival.

Sellas also expects fourth-quarter topline data from its Phase 2 study of SLS009 (Tambiciclib) in newly diagnosed AML. 

Why Is SLS Retail Still ‘Extremely Bullish’?

On Stocktwits, retail sentiment for SLS jumped to ‘extremely bullish’ from ‘neutral’ levels a day ago amid a 308% surge in 24-hour message volumes.

One user challenged sellers after the long-awaited milestone. “After all this time, the ONE THING that everyone waited for actually happens and we’re scared?” the user said. “The one thing that mattered happened and some of you folded like a cheap suit.”

Another user said they bought during the slide. “Ended up loading my small boat at 9.92 during the first two dips. No worries here! But wow, unexpected.” The user added, “The anticipation of the data coming fairly soon will ignite the FOMO and then once again when data presented.”

A separate user speculated that a buyout offer could precede the results: “I wouldn’t be surprised to receive an initial BO offer PR being put to SH. Or topline could come first. Let’s see…” 

Some bulls also challenged survival estimates: “The blind Regal data hasn’t even been unblinded yet, so stop recycling basic Google snippets and pretending you have insider insight.”

SLS stock has jumped 175% year-to-date.

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