u/Efferdent_FTW

Here we go!

Implanted radioactive seeds into tumours is not new. DaRTs is an upgrade to it. I've been reading some common criticisms of DaRTs and thought it would be constructive to address them. So let's dive into some comparisons between the two.

Safety

ALARA (As Low As Reasonably Achievable) rules are agnostic to source of radiation. They will apply to all radiopharmaceuticals, nuclear medicine, etc. So yes, DaRTs will also have strict handling protocols for staff and patients. This is not new or scary, nor is it a barrier. If there was a previous assumption that DaRTs could just be transported in a ziploc bag from manufacture to OR, that's just not the case. With that said, hospitals are equipped for these safety protocols. This doesn't make DaRTs niche or requires a special hospital. If anything, the considerations are less. Alpha radiation is stopped by a sheet of paper or a few cm of air. Here is the safety comparison:

ALARA domain	Traditional BT	DaRT
Shielding required	Lead-lined room (HDR) or lead aprons (LDR)	Steel transport cask; no special room required
Staff procedure dose	65–420 µSv to hands (LDR); near zero if room evacuated (HDR)	0.9–5.2 µSv total body dose during entire procedure
Patient isolation	Weeks to months (LDR permanent); inpatient days (LDR temporary)	~1 week precautions; seeds removed at ~14 days
Contamination route	Dislodged seeds; body fluids (unsealed isotopes)	Glycerin carrier fluid containing Pb-212 daughters
Post-discharge public risk	Significant for months (I-125)	Negligible within days of seed removal
Regulatory reporting	Lost seed = reportable event	Same

Radiation

DaRTs are a form of brachytherapy, they aren't exclusive of each other. Prostate cancer is the most common implement of brachytherapy. Radioactive seeds are implanted into tumours, radiation kills tumours. Traditional brachytherapy uses beta and gamma radiation, which have a wider kill zone which is why there are so many side effects. Beta and gamma are also weaker. Traditional brachytherapy is also sensitive to hypoxic tumour conditions, which limits their efficacy.

It's not one or the other, DaRTs are a complete upgrade of traditional approaches. Oncologists who are already using brachytherapy routinely now have a tool which is more specific, more powerful, safer and possibly has a stronger immune effect (when combined with immunotherapy). Currently, brachytherapy's use of beta and gamma radiation has a much weaker immune effect. The reason is that the wide kill zone results in immune suppression due to radiation exposure.

Isotope	Half-life	Decay chain	Radiation / penetration
Iridium-192	74 days	¹⁹²Ir → ¹⁹²Pt (beta, ~95%) or ¹⁹²Os (electron capture, ~5%), both stable	Gamma + beta. Gamma penetrates several cm at avg 380 keV. Significant dose to surrounding tissue, lymph nodes, vasculature.
Iodine-125	60 days	¹²⁵I → ¹²⁵Te (electron capture), stable	X-ray + gamma. Low energy avg 28 keV. Penetrates ~1–2 cm. Continuous low-dose exposure for months.
Palladium-103	17 days	¹⁰³Pd → ¹⁰³Rh (electron capture), stable	X-ray only. Very low energy avg 21 keV. Penetrates ~0.5–1 cm.
Cesium-131	10 days	¹³¹Cs → ¹³¹Xe (electron capture), stable	X-ray only. Avg 29 keV. Penetrates ~0.5–1 cm. 90% of dose done within ~1 month.
Cesium-137	30 years	¹³⁷Cs → ¹³⁷mBa (beta) → ¹³⁷Ba (gamma), stable	Gamma + beta. High energy 662 keV. Penetrates several cm. Largely historical — replaced due to security concerns.
Radium-224 (DaRT)	3.6 days	²²⁴Ra → Rn-220 (56 s) → Po-216 (145 ms) → Pb-212 (10.6 h) → Bi-212 (61 min) → ²⁰⁸Pb stable	Alpha ×4 + beta. Alpha range <0.1 mm per particle in tissue. Daughters diffuse 2–4 mm into tumor by recoil. Immune cells outside tumor are not irradiated. Chain complete within days.

Immune system

Wider penetration means exposure to healthy blood vessels, lymph nodes and surrounding tissues. Lymph node penetration will lead to systemic immune response suppression which renders concurrent immunotherapy weaker/ineffective.

I don't know gribs, but I find their personal claims to be disingenuous. IF DaRTs continues exceeding tumour control expectations and maintains a healthy safety profile, it would be ridiculous that it isn't used. My colleagues are skeptical due to it's current pipeline phase, but have said the same thing: "if this comes to fruition, it will save millions".

Brachytherapy is mail, DaRTs is email.

Brachytherapy is bows and arrows, DaRTs is an AR-15.

Brachytherapy is a horse, DaRTs is a car.

As always, let me know if I'm missing something or if I got something wrong. Always open to learn.

TL;DR - We have some institutional bulls backing us. Came $0.06 shy of triggering a buying frenzy that would've shot price up to $11+. June 17th will be interesting. Watch for $12.50 and $15 marks, time your buys at those points. Not a financial advisor.

For context, DRTS popped up on my radar about 2.5 weeks ago and I've since gone down the rabbit hole (thank u/Pristine_Hurry_4693). This is the first options (May 15th) close period I've witnessed live with DRTS. I love using Tradingview for it's indicators and I stumbled upon a custom indicator set on Reddit that is pretty damn accurate for predicting entry/exit points by visualizing momentum through stacked multi-timeframe EMAs. That is shown in the middle with the green, red, and blue lines. The bottom is the Williams R% where essentially 0.00 = overbought, -100 = oversold. The top is just your standard price action/candlestick panel.

https://preview.redd.it/wkdzkz0rx71h1.png?width=1742&format=png&auto=webp&s=fe65617f56ec9d3f46e4df41bb1820110084b102

Yesterday was the last day to buy/sell the May 15th options, so I was curious to see who would duke it out. We have our market makers (MM) who want to keep pricing under $10.50 so options expire worthless, but I wanted to see if the other side was mainly retail investors or if there is some big money invested in calls as well. We started the day off with huge volume pushing pricing up to $10.50. There's some back and forth with big volume drops by MM to kill upwards momentum, keeping pricing at the $10.21-26 mark. At 3:47 that's when the institutions with calls came in, big volume buys and they were duking it out with MM. At 10:58, institutions pushed it to $10.44, but MM came in at 10:59 and nuked it to $10.38. If it hit $10.50, MM would trigger a gamma squeeze and go on a buying frenzy to cover their exposure which would've driven the price upwards in milliseconds. Total volume was 1M compared to the average daily of 439k.

Looks like we have some big boys backing the bull and likely more big boys coming. The next interesting date will be June 17th. If pricing hovers around the $12.50 or $15 mark in the last 10 minutes of market open, gamma squeeze will trigger. This would be the time to buy. This is all assuming, ASCO + earnings doesn't blow it completely out of the water! Not a financial advisor, just a passionate trader and also work in the healthcare industry.

This announcement was n=3, so a tiny pool. As was spoken about in the call, car T cell therapy also wiped out tumour size, but it came back. The median time is 1-3 months of return. Patients were treated with darts between Dec 2025 - March 2026. Data cut off was May 3rd, so we're 2-4 months from treatment date to data cut off. As of right now, no tumour return, but there's still a window. Alpha Tau hasn't cured GBM....yet, BUT they are in the right direction.

This was a feasibility and safety study. ~20% increase from objectively weak data is astounding. Let's cross our fingers and count down the days to ASCO.

My friend's dad passed from pancreatic cancer 3 years ago. It was a really tough road for their family and hope was a really powerful thing.

Company called Alpha Tau just presented data on a treatment that delivered 100% local disease control across every evaluable patient. Including people who already failed multiple rounds of chemo. The procedure is outpatient. Side effects mostly cleared within 2 weeks.

Its called Alpha DaRT and their ASCO presentation coming next month. It's in really early stages, but I'm praying this can bring hope to those who need it.

The next biggest hurdle for DRTS is the triggering of the abscopal effect. What is that? So what we know is that the alpha darts destroy tumour cells with alpha radiation which obliterates double stranded DNA. The dying cells release damage-associated molecular patterns (DAMPs) and tumour antigens that activate dendritic cells and cytotoxic T cells and stimulate the immune system to attack similar cells, serving as a "cancer vaccine" which is crucial for small distant metastases and remission. This is called the abscopal effect. In order for alpha darts to be seen as truly ground breaking, this absolutely needs to be triggered.

I think this call will demonstrate the successes of not only complete tumour regression, but also show data regarding immune markers indicating the abscopal effect is triggered. Here's to hoping!

I think it's important to look at the macro view of what a company brings and what that value actually means in the grand scheme of historic inner-industry comparisons. I did a semi-deep dive. When running the stats of 300-400M cap biotech that develop oncology drug treatments, only 3.3% make it from phase 1 to approval. Once a drug reaches phase 3, approval jumps to 35.5%. Median time spent in oncology clinical development is 13.1 years.

This all changes depending on response rates in Phase 1 studies. It needs >40% response rate in phase 1. Now this is where the data gets interesting because these are pharmaceutical interventions, not physics-based interventions. When looking at physics-based interventions, three out of four alpha-emitter small-caps that went through similar development were acquired. The fourth was still acquired despite disappointing Phase 3 data. Why? Because large pharma wanted the moat. They want the manufacturing infrastructure and IP.

Let's look at DRTS. The patented seed-design covers the specific mechanism of using Ra-224's decay chain which expands alpha irradiation from microns to millimeters. This is the foundation of the treatment. The moat is the 150+ patents that include the engineering, clinical buildout, seed construction, treatment planning system, delivery device engineering, combination therapy protocols, and more. The treatment planning system includes their dosimetry algorithm outlining seed placement given tumor geometry. That's the treatment roadmap. These not only form the moat, but that moat is deep and wide.

But wait, there's more. They are also buying the regulatory approvals and designations which the FDA has already granted for cutaneous squamous cell carcinoma, recurrent squamous cell carcinoma of the oral cavity and recurrent gliobastoma. Also, the manufacturing infrastructure, licensed facility and the clinical data set.

Let's look at historic winners and losers:

NovoCure had a $400M cap, uses a physics based approach, used the same multi-indication expansion strategy (started with recurrent squamous cell skin carcinoma then moved to pancreatic and GBM). Current market cap $8B.

RayzeBio, raised $160M + $311M IPO, used actinium-225 (alpha emitting isotope), early Phase 1b data showed encouraging efficacy and tolerability. Acquired by BMS before Phase 3 results were in.

Tokai Pharmaceuticals, compelling Phase 2, valid mechanism, designed their Phase 3 to go head to head against the category leader. Data monitoring committee determined the trial was unlikely to meet primary endpoint. Shares tumbled 70%. DRTS avoids this by having 5 concurrent US trials across different indications instead of binary readout.

Sorrento, filed for bankruptcy amid mounting debt and ongoing lawsuits. Clinical-stage companies burn through $100M a year without revenue. DRTS is not immune to this.

I wrote this post personally with research done with claude, where I checked the sources to verify. The next two months is crucial. Announcement of podium speech at AHNS is huge. ASCO is promising, not a Plenary Session, but poster presentations aren't often seen as ground-breaking. This can likely be because of the stage of the research as opposed to the mechanism itself.

What do we think will happen with MU next week with these beefy earnings calls?