SLS Stock Extends Rally Overnight: CEO Says ‘Bullish’ Leukemia Data Could Drive NCCN Recognition For GPS

• The CEO said positive Regal data could potentially help GPS gain broader NCCN recognition beyond the current AML setting.
• Earlier GPS data showed median survival of 35.5 months in older AML patients and 21 months in relapsed AML patients who did not receive GPS, versus 5.4 months.
• Stergiou also contrasted Sellas’ SLS009 AML drug with AstraZeneca's discontinued CDK9 programs.

Shares of Sellas Life Sciences Group (SLS) rose 2% in overnight trading heading into Thursday after CEO Angelos Stergiou said he is “very bullish” on upcoming Regal data that could potentially help push its flagship cancer drug GPS toward broader National Comprehensive Cancer Network (NCCN) recognition in acute myeloid leukemia (AML).

SLS stock jumped 6% on Wednesday, on track for its fifth straight week of gains and its best month this year. 

SLS CEO Flags Longer Survival For GPS 

Stergiou made the comments during TD Cowen’s 7th Annual Oncology Innovation Summit on Wednesday as investors focus on the company’s late-stage Regal trial, one of the biggest near-term catalysts for Sellas. 

The Phase 3 Regal study is evaluating galinpepimut-S (GPS), an immunotherapy targeting the WT1 cancer antigen, in AML patients who have achieved a second complete remission but are not eligible for stem cell transplant. The Regal study recently reached 78 out of 80 required events, with the 80th event serving as the trigger for final analysis and topline data disclosure.

The CEO said at the summit that the study has continued significantly longer than initially projected, which investors interpret as a potentially positive sign for survival outcomes. “80 events have not occurred yet, almost 25 months after enrollment completion, which obviously indicates longer survival than projected,” Stergiou said.

Stergiou reiterated that “every passing month” may improve the probability of a successful outcome due to a potential GPS effect. The company previously said the study was designed to show that GPS-treated patients could live longer than those receiving standard treatment, with a median overall survival projected at about 12.6 months versus 8 months in the control group. 

According to Stergiou, anything above a four-month survival difference would be considered “very clinically significant,” though he added the company hopes to see an even larger benefit.

SLS Eyes NCCN Recognition For GPS

One of the most closely watched comments from the conference came when Stergiou said that positive Regal data could potentially support broader NCCN recognition for GPS beyond the current trial setting. “I would also expect, depending on the data that we will see, and what I believe is that there’s a good chance that the REGAL trial would show GPS to have a median survival very similar to what [we] showed in AML CR1, to get NCCN guidelines also in the CR1 setting,” Stergiou said.

The CEO added, “We’re very bullish, but at the same time we’re very pragmatic.” Stergiou also said that GPS could emerge as a maintenance therapy option for AML patients after remission, noting that no therapies are currently approved for AML CR2 maintenance.

SLS Points To Strong GPS Survival History

Much of the TD Cowen discussion focused on earlier GPS data that continues fueling optimism ahead of the Phase 3 readout. Stergiou called the prior AML data “quite unprecedented” after Sellas reported a median overall survival of approximately 68 months in a Phase 2 study following first complete remission.

In AML patients aged 60 and older, the company reported a median survival of 35.5 months. The CEO also pointed to earlier data in relapsed AML patients who achieved second remission, where GPS-treated patients showed a median survival of 21 months compared with 5.4 months for patients who did not receive the therapy. 

The latest comments also come after Stergiou discussed new real-world data involving elderly AML patients treated at MD Anderson Cancer Center in a LinkedIn post on Tuesday. According to the CEO, newer chemotherapy combinations are helping more elderly AML patients achieve remission, but most still fail to reach stem cell transplant.

“Despite being touted as a ‘bridge to transplant,’ only 15% of these patients actually made it to an allogeneic stem cell transplant,” Stergiou said. “For the remaining 85% who are too frail or older, a steep therapeutic cliff remains.” The CEO used the findings to reinforce Sellas’ thesis around GPS and the unmet need in elderly AML maintenance therapy.

CEO Says SLS009 Could Succeed Where AstraZeneca Failed

Beyond GPS,  Sellas’ second AML program, SLS009, a highly selective CDK9 inhibitor currently in Phase 2 testing, is also gaining traction. During the TD Cowen summit, Stergiou contrasted SLS009 against earlier CDK9 programs from companies including AstraZeneca that were eventually discontinued.

“Other programs, such as AstraZeneca, they are CDK9 inhibitors who discontinued their programs,” Stergiou said. “They are not as selective and specific to the CDK9 target as SLS009 is.” The CEO said SLS009 remains in the body “long enough to kill cancerous cells, but not long enough to cause severe toxicities.”

Sellas expects topline SLS009 data later this year and said it may pursue accelerated approval depending on the results.

How Do Retail Traders Feel About SLS?

On Stocktwits, retail sentiment for SLS slipped to ‘bullish’ from ‘extremely bullish’ levels a day ago amid ‘high’ message volume.

One user said, “The asymmetric move that this is going to make will be Glorious.”

Another user said, “Mark this. All the bears have it wrong. This is going to the moon, better than any AI play today.”

SLS stock has surged 345% over the past year. 

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