GPS
The Gap, Inc.
stock NYSE

Those are fair starting points, but once you consider the biology at play, what are the chances that AML CR2 patients' mOS would be 36 months?
We have 48 people still surviving, with the 80th event lowering that to 46. For the HR to actually fail (>0.636), BAT needs roughly 28% of its arm still alive at 3 years on a simple head-count. To argue that this is going to end up in a failure, you have to confidently push BAT 3-year survival up toward about 30% (roughly 1.5–2× the realistic level) and give GPS almost no extra tail of its own (but why? the evidence suggest otherwise). You have to stretch the inputs well past what the data supports to find a losing scenario. That's the whole point - and I am yet to see an argument that wouldn't have to go into defying biology and the available data and without giving GPS absolutely no credit.

Historical non-transplant CR2 relapsed AML runs at 10–15% 3-year survival (Kurosawa non-transplant was like 14%? and (!!) at a younger median age than REGAL). Even if you hand the venetoclax era and REGAL's healthier-than-average enrollment a generous bump, you top out somewhere in the high-teens to low-20s, but nowhere near 30%.
Again, this is obviously a risky choice, but the odds seem to be slightly better favoured, and the other reasons (one or another) you noted apply to other biotech stocks nonetheless. If you would not invest in what is believed to be a successful drug because of fear of what the regulation may do, then it will be very difficult to invest in any pharma stock whatsoever.

If this was true then you would know the risks
I think the risks can be summarized like this:
Binary trial outcome: The biggest risk is that the final analysis of overall survival does not reach the pre-specified statistical threshold. Even if patients appear to live longer, the trial must demonstrate a statistically significant benefit over the control group.
Unknown treatment vs. control split: Knowing there have been 78 of 80 deaths (events) tells us the trial is nearly complete, but it does not reveal whether significantly fewer deaths occurred in the GPS arm than in the control arm. That comparison determines success or failure.
Borderline statistics: If the hazard ratio or p-value ends up just missing the required threshold, the trial could be viewed as unsuccessful despite showing a clinically meaningful trend.
Regulatory risk: Even with positive survival data, regulators may decide that the evidence is not strong enough on its own or require additional data before approval.
Financial risk: Like many small biotech companies, SELLAS may need additional financing if approval is delayed or the trial does not support commercialization, which could dilute existing shareholders.

An extended access program for the drug has been active for years. It is driven by demand from the treating physicians in Regal (an open-label trial). So the docs who are administering GPS have been asking for more for other patients, primarily in a post-transplant setting.
Which is another reason why the low-ball buyout ranges you see (below $75/share) are missing the forest for the trees. SLS is going to totally reshape the AML market with SLS009 and GPS. And big pharma knows it.

Notice how the GPS never says made a mistake, it says recalculating route😉

Sure, the AML TAM is over 5-6B a year in peak sales. Slap a 4x multiple on that and youre at 20B. that gives 0 credit to the post transplant market or expansion for GPS solid tumors, or the SLS009 platform. That is purely AML frontline + CR1 + CR2
What i meant in my post by market mechanics is that buyouts are typically some control premium \* market price. Look at APGE. BP paid a 50% control premium - stock was at 95, buyout was for \~133.
This means that if we're trading at 60 after the unblinding, the buyout floor is around 90 (i argue 100 since there will almost definitely be multiple bidders).
GPS TAM in and of itself easily validates this, but market mechanics will force the acquirer's hand.

Based off of previous buyouts and how BO is typically calculated, can you explain to me how you came to that number? That’s around 18b and not sure if fully diluted or not. Is that for Regal and GPS or Regal only? I’m sincerely curious, I own a good amount of shares myself

Both were correct. Let me explain.
The drug category that SLS licensed from Sloan-Kettering (GPS) was viewed as a non-starter. It had not worked enough times that nobody was interested in it.
There are still shorts out there that are convinced that this will never work and that we'll all be crying after the 80th person in the Regal trial finally dies. Mathematically, they're wrong and they have no way of saying that the BAT could possibly keep people alive this long or it means that there was severe coordinated medical malpractice going on in Leukemia for the past several decades. Seems very unlikely.
Now that we have the clearer picture, that the drug has worked and worked better than anyone expected, we know how the movie ends. SLS doesn't have the financial resources to commercialize GPS, particularly as its still going through the costs of Phase II on its other drug. So, someone will come in and buy it and everyone: SLS, the acquirer, the patients who only had 10 months (on average) of life, and the shareholders will all be dancing and singing while the shorts go and try to find some other picnic to rain on.

SLS became a binary with a massive payoff and the odds became too great to pass up for many.
What's unique about that from a stock perspective is that biotechnology is NOT known for providing any certainty whatsoever. After months (and months and months and months) of waiting for the 80th event, there were no longer any reasonable models that showed SLS's GPS wasn't going to the moon.
Alpha Tau went through a nearly identical "prove it until it's derisked" phase. Trial after trial after trial proved safety/feasability on the hardest to reach/treat tumors. No other brachytherapy solution could work against PanC, for instance, because of the potential damage to surrounding organs. Alpha Tau achieved a 100% DCR on PDAC because it's high LET alpha decay radiation has zero effect on the surrounding healthy tissue. This lack of impact on healthy tissue positions Alpha Tau not just as a front line Standard of Care for cancers like rGBM but gives it the ability to work with systemic treatments like Chemo, Daraxonrasiv or Keytruda where the last thing you want is a local treatment that will put the immunity system of the patient at risk.
So, you wind up with SLS treating a broad range of cancers because of their approach and you wind up with DRTS treating nearly all solid tumors with their approach.
At the end of the day, the two couldn't look more different to an oncologist (systemic vs. targeted, soft tissue vs. solid tumor, drug vs. device, etc.) but to the biotechnology investor seeking broad coverage and derisked opportunity, they wind up nearly identical.
Someone tried to draw the distinction that SLS will almost certainly be bought out and DRTS will almost certainly be commercialized. I'm not so sure. If you go through the board of directors at Alpha Tau, you'll find several people that have deep bench experience with M&A. If someone brings a $5B or up BO to the Alpha Tau board, I'm not sure they'll be able to turn it down. I am, however, certain that any big pharma that buys Alpha Tau will make back that investment within two years depending on how fast the FDA starts approving the pivot trials.

Why isn't it $1? Or 1 billion? Price discovery. Market manipulation. Shorts. This is one trial for one drug for one condition. It looks great. What will the other trials for other conditions for GPS AND their other drug be? What would a bidding war look like?
Do you know any stocks that are priced to perfection and the price doesn't go up or down? What stock is that?
Other bio stocks that rapidly rose in value in the past, why did they do that? Why couldn't that same thing that's happened many times before happen again?

That’s factually incorrect.
The money spent on space exploration is 100% spent on people and companies on earth. A huge amount of technology that is being developed as part of space projects ends up in everyday household items that benefit everyone.
That being said, unless space becomes a self-sustaining economic force, it’s not worth investing a penny on the stock market, because nearly all money comes from government contracts. You’re better off investing in companies who use the spin-off technologies and market that towards products for terrestrial use.
Some examples:
CMOS sensors, IR thermometers, LASIK, Cochlear implants, aircraft anti-icing systems, earth observation for agriculture and land surveying, solar panels, GPS, dry lubricants, gold plating…

The sample size is bigger than 80 also, around 130, of those 130 we don't know how many are on GPS and how many are on BAT, but from my research BAT patients survival rate is 8-10 months, the trial has been running since 2021 and reached full enrolment in April 2024, so at the very least, some GPS patients have lived 26 months
My knowledge is limited to my basic research, I don't fully understand clinical trials, but seems like the data stacks up

Ok this is a pet peeve of mine.
OP I need you to learn. Just because something happens doesn't mean it's AI.
Just an FYI your account could also be restricted in 2020 before AI.
Please stop calling everything AI.
Hey guys, my GPS showed me this route to work today. AI is really good.

GPS has been running way way too long. Bears are going to BURN.

ATYR has been discussed in sellas 
 subreddit a lot..ATYR didn't had statistically much success rate when modeled and it didn't have much public avaliable data parameters  to model like GPS....

First of all, a p-value of 0.02 doesn't mean there is a 2% chance the outcome was random chance. This is simply an incorrect statement of statistics. The p-value means there is a 2% chance of observing data like that if the null were true-very different. A p-value is P(data showing these results | drug does nothing), not P(drug does nothing | data).
This is relevant, because second, here is your model:
True HR || Regal chance of significance
0.26 99%
.5 87%
.55 76%
.6 62%
.64 50%
.75 25%
.85 11%
We aren't looking for a drug that doesn't not work. We need one with a true HR below 0.64. A few extra months from the control group raises the HR, possibly above .64.
a 21 vs 5.4 month split carries a massive sampling error, especially on a small cohort. Meaningless.
Long survival in both arms looks identical to our current results, but shrinks the HR...a lot.
This isn't saying GPS is going to fail. It probably won't. But pretending like this is a guaranteed trial is dumb.
To anyone reading this, yes, I just spent 20 minutes modeling to shut this doofus who doesn't understand what a p-value is up. Guess I probably lost that interaction!

Why are you quoting other trials when you're being asked for a hard data, mathematical or biological scenario where GPS can fail?
Here I will help you with some numbers:
Trial started enrolment February 2021, final 20 patients enlisted April 2024, interim analysis 60 events at January 2025, 72 events by end of December, 78 events by April 2026. Median OS of BAT is 6-8 months, up to 11 months if care is provided by academic institutions instead of regular hospitals. Phase 2 trial demonstrated 5.4 month median OS for BAT vs GPS's 21, with a P-Value of 0.02 - meaning 2% chance the outcome was random chance. And this was 12 doses of the GPS drug, not ad ad infinitum like what Phase 3 got updated to because doctors begged for it.
Let's your math on how ***GPS*** fails. Not some article about some other biotech, not some other drug where we didn't know the biological and mathematical constraints. ***GPS.***
For anyone still reading this conversation - this is exactly what I was talking about. Bears can never argue with the math which is why they keep dodging it as hard as they can.

Irrelevant example, as the reason for their halt (failure to improve survival OS) cannot feasibly apply to SLS at this point. You have two possible bear conclusions: We are seeing historical results from BAT, or the trial is flawed. There is more evidence against those 2 options than supporting them.
Dr. Tsirigotis spoke at a P.R. event in September 2025 about his observations and belief in SLS and has the highest number of enrolled patients under his care. He explicitly point out GPS as the reason his patients are consistently outlining expectations.
Below is a decent read about why the most common bear cases don't hold water.
https://www.chaotropy.com/sellas-why-the-bear-case-might-not-hold-up/

There has already been partial unblinded results at the announcing of event 60, with treating doctors stating that GPS is responsible for the increased survival time and quality of life. We also know that GPS had been requested and received permission to be utilized in an unlimited fashion: infinite dosing as deemed necessary by the treating doctor.
The trial event timeline was also shortened from it's original number of 126 to 80, as patients were surviving much longer than expected.
The final readout is the last shoe to drop, but there is plenty of information available in the mean time.

They don't have to buy SLS009, they can just buy GPS.

Every single bear case comes down to "What if?" and "Anything can happen."
The subject sample size is what's needed for statistical power, it is not "small".
Feel free to post a mathematical or biological scenario where GPS can fail. You can't.