Primary-sourced models; adjustable sliders = undisclosed assumptions. Live · GitHub · Explain tab for methodology. Not investment advice. Phase 3
ReSTART
How this works
Fact ReSTART (NCT05323253) is a pivotal single-arm study of intratumoral Alpha DaRT in recurrent cutaneous SCC. Primary endpoints: ORR (confirmed BOR per RECIST 1.1) and DOR at 6 months. Enrollment completed with 88 patients (May 2026 PR). Breakthrough Device designation; first modular PMA module submitted Jan 2026.
Model Wilson CI + exact binomial tail vs historical benchmark p₀ (26–40% recurrent cSCC systemic therapy range; see table). Monte Carlo simulates n=88 outcomes from a Beta prior around your assumed ORR. Assumption ORR threshold 35% until public SAP.
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ReSTART ORR model. Observed responders k = round(n × ORR%). Wilson score 95% CI. One-sided P(X ≥ k | n, p₀) via exact binomial sum. MC co-primary: true p ~ Beta(20p, 20(1−p)); win requires ORR gate (threshold + beat bench) and durable-responder fraction (each responder durable with P(DOR≥6mo) prior from PD-1 comps). Deterministic DOR months slider is sensitivity only — not used in MC draws. PMA timeline includes clock-stop uncertainty band (heuristic).
Assumption Undisclosed — not ReSTART result. FIH DaRT SCC/H&N 78.6% CR (28 lesions, different design) — Arazi et al. · Cemiplimab metastatic ORR 47% is PD-1 comp, not direct anchor — Migden 2018
Assumption Default 35% until public SAP filed. ◆ marks model default. Primary endpoints on ClinicalTrials.gov.
Assumption Deterministic sensitivity only (pass/fail vs 6-month gate) — not used in MC co-primary draws. NCT05323253
Verified ◆ 6 mo = ReSTART DOR co-primary per protocol. Deterministic gate only. NCT05323253
Model MC co-primary prior — each responder durable with this probability. Default 81% from pembrolizumab LA cSCC (DOR ≥6 mo in 81% of responders) — Merck 2021
Assumption MC win requires durable/responders ≥ this fraction (co-primary DOR gate). Not a public SAP threshold.
Model Subjective prior blended 45% with structural ORR/DOR score. Breakthrough Device + modular PMA module 1 submitted Jan 2026 — Shareholder letter
Verified Module 1 submitted Jan 2026. Modular PMA timeline heuristic only — not FDA clock. FDA modular PMA
Assumption Adds uncertainty band to PMA ETA (mean ~3 mo/stop ±1.5×2). Heuristic — not FDA clock.
Model outputs
Responders (assumed)
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ORR 95% Wilson CI
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P(ORR > benchmark)
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DOR gate
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Combined P(PMA)
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MC trial P(success | assumptions)
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MC ORR-only P(success | assumptions)
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Readout timing
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PMA ETA (clock-stop band)
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Monte Carlo ORR distribution (seeded, n=1500 — slider hidden, fixed for perf)
Model Single-arm ORR+DOR co-primary gates are educational under slider assumptions — not a forecast of FDA approval. Historical-control bias and PMA review risk remain; a ~96% MC trial P(success) is not ~96% PMA certainty. Valuation applies a separate PMA approval haircut when skin P(s) is linked.
Prior FIH DaRT in SCC/H&N: 78.6% CR in 28 lesions — PubMed 31759075 (different design; not ReSTART).
Regulatory decision tree FDA + commercial
MC feeds topline pass rate only (ORR+DOR co-primary). FDA/PMA branches and commercial ramp are separate sliders — not derived from MC. Per-path share stress (88M approve · 100M fail/defer · 110M reject) applies when branch dilution is on. Output: EV + equity $/sh by path + weighted scenario.
Verified Modular PMA path — FDA modular PMA · module 1 submitted Jan 2026
Assumption Clock-stop / additional module requests — not FDA clock.
Assumption Fast = 1.4× base pen · base = slider · slow = 0.6×
Model Base ramp branch — 1.0× valuation pen slider.
Assumption Slow = 0.6× base pen in tree leaves.
MC topline pass (input)
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Weighted tree EV
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Weighted equity $/sh
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Path
P
Shares (M)
EV $M
Equity $/sh
Limitations: Single-arm ORR inference vs historical p₀ — not a randomized HR. Deterministic DOR is pass/fail sensitivity; MC uses per-responder durability prior (not KM). MC trial P(success | assumptions) is educational co-primary success under model gates — not PMA approval certainty. PMA timeline + clock-stop band is heuristic. Does not model FDA advisory panel or Cemiplimab SoC erosion.
Fact Five concurrent US IDE trials plus Japan approval and Tolmar urology deal — catalyst windows from company guidance and ClinicalTrials.gov only. No invented readout numbers.
Early REGAIN interim is n=3 feasibility only — local disease control ≠ OS. IMPACT primary endpoint is SAE rate, not ORR.
Pipeline map
Catalyst timeline model
Primary-sourced windows on the year axis; details and sources listed below in date order. Bars marked → continue past year end.
Pipeline models feasibility · display-only
Modular PMA clock-stop band, IMPACT wide prior (no US response data), and REGAIN n=3 posterior — feasibility not pivotal. Pilot posteriors cannot set registrational P(s) above a 15% hard cap (display-only; do not drive valuation P(s)). REGAIN interim n=3 per Jun 2026 PR.
Bear case honest
Skeptic / filing risks cross-checked in RESEARCH.md — not a recommendation to short.
Risk
Verdict
Tag
Notes
Community threads reference
High-signal discussion hubs — sentiment only; verify every claim against primary sources in RESEARCH.md.
PubMed 39398444 — EUS pancreatic DaRT first-in-human (n=5 feasibility)
How this works
Model EV = Σ (peak sales × EV multiple × P(success|indication)) + platform option ($M, not $B). Peak sales ($M/yr) = eligible patients/yr × penetration × years on therapy × price ($K) ÷ 1,000. Risk-adjust toggle multiplies each indication by its P(success) slider. Linked skin P(s) = ReSTART trial co-primary × PMA approval haircut (default 75%) — not MC trial success alone. Five indications: skin, GBM, pancreas, prostate (Tolmar), Japan H&N (Shonin).
Fact Cash ~$80.2M (Mar 31 2026); ordinary shares outstanding ~88.0M per SEC F-3 / 20-F (not ADS). F-3 shelf up to $300M + $100M ATM — dilution stress presets available. Runway uses cash burn (CFO interview, company-reported, not audited CFS), not GAAP net loss or operating loss — Q1 2026 PR · CFO interview. Tolmar: 60% of net sales as supplier — Jun 2026 PR.
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Valuation model. Per-indication peak ($M/yr) = patients/yr × pen × years × price ($K) ÷ 1,000. EV contribution = peak × mult × P(s). Indications: skin, GBM, pancreas, prostate (60% Tolmar supply share), Japan H&N (Shonin). Risk-adj equity $/sh = (EV + cash − debt stub) / ordinary shares (M) — default ~88.0M per F-3/20-F; header $/sh uses v_shares. Header “vs-ref” compares model equity (EV+cash) to shares × illustrative ref price (assumption, not live). Linked skin P(s) = ReSTART trial co-primary × PMA approval haircut (default 75%) — MC alone is educational trial-gate success, not approval certainty. Dilution stress presets (100M / 110M) stress-test F-3/ATM capacity. Commercial bull (ops) caps platform optionality at $8M (not $B). Runway = cash ÷ quarterly cash burn (CFO interview, not audited CFS). Not a DCF — educational sum-of-parts only.
Platform correlation: Skin approval ≠ full de-risk of GBM, pancreas, or prostate. Each indication keeps separate biology, endpoints, and registrational paths — use the correlation controls below.
Model default burn $6.5M/qtr for runway math Model — midpoint of CFO cash-burn range (company-reported interview, not audited CFS); not GAAP op loss
Ordinary shares 88,009,737 (~88.0M) Verified · SEC F-3 · 20-F FY2025 — model default; header $/sh uses this denominator
F-3 shelf + ATM up to $300M shelf + $100M ATM Verified · SEC F-3 — capacity, not imminent issuance; dilution stress (100M / 110M shares) available below
Valuation controls
Blue = defensible prior band · Red = aggressive · ◆ = filing anchor
Model Single-arm ORR+DOR gates are educational; PMA is not ~96% certain when MC trial P(success) is high — historical-control and FDA review risk remain. Linked path: trial P(success | assumptions) × PMA approval haircut → model approval P(s) used in EV.
Platform correlation
Model 0–1: non-skin P(s) blends toward skin — α-physics transfer, not approval certainty. Works with or without link toggle (uses max(link λ, mechanism) when link is on).
Assumption 0–1: seed placement / anatomy feasibility penalty on non-skin rows — GBM > panc > prostate > Japan Shonin weights in model.
Assumption Legacy 0–30% EV reduction on GBM/panc/prostate/Japan rows — supplements mechanism + delivery dials.
Model When link toggle is on: each non-skin P(s) = (1−λ)×slider + λ×skin P(s). Independent biology still dominates at low λ.
🔬 Inverse mode
Uses live quote mkt cap when available; else shares × illustrative ref price. Backs out implied skin penetration or P(commercial) holding other sliders fixed — identifiability check, not a price target.
Target equity (mkt cap)
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Implied skin pen
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Implied skin P(commercial)
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Skin cSCC (ReSTART)
ModelProcedure economics: peak = eligible × penetration × price ($K/procedure) — one-time intratumoral device, not years-on-therapy drug revenue. EV = peak × P(s) × multiple; the multiple is a terminal value proxy (device M&A ~3–6×), not a DCF of recurring procedure years. Procedure-years slider fixed at 1.
Estimate US recurrent/locally advanced cSCC addressable (~12K/yr default). SEER skin cancer
Assumption Intratumoral device share vs PD-1 SoC (cemiplimab/pembrolizumab).
Assumption No US list price — procedure-based device economics.
Model When linked: trial co-primary P(success) × PMA approval haircut (not MC alone, not approval certainty). Unlink to set manually — divergence is surfaced. NCT05323253
Assumption Haircut applied only when link is on: approval P(s) = trial P(success | assumptions) × this factor (default 75%). Captures historical-control and FDA review risk beyond educational co-primary gates.
Verified Tolmar deal: 60% of net sales to Alpha Tau. FY2025 PR
Japan H&N (Shonin)
Assumption Japan unresectable/locally recurrent H&N addressable pool — not disclosed; modest default. Shonin approval verified — PR · SEC 6-K.
Assumption Commercial ramp P(s) — approval is real; PMS n=66 at 5 centers is post-marketing, not revenue proof. Reimbursement timing unverified.
Verified ◆ Default ~88.0M ordinary shares (88,009,737) per SEC F-3 / 20-F. Header and valuation $/sh use this slider. Prior model used ~42M “FD ADS” — incorrect denominator.
Fact F-3 shelf up to $300M + $100M ATM (Apr 2026) is capacity, not imminent issuance — SEC F-3. Dilution stress bumps the share denominator only; the model does not auto-issue against shelf size.
Assumption Illustrative market ref as-of ~Jul 2026 (~$13 Yahoo/market snapshot) — not a live quote or data feed. Used only for header vs-ref upside (model equity vs shares × ref).
company-reported interview, not audited CFS ◆ Default $6.5M/qtr — CFO interview cash burn ~$5–6M+/qtr (~$25M/yr), ramping with trials. CFO interview. GAAP op loss Q1 $13.3M and net loss $22.9M (incl. $9.6M non-cash warrants) are not cash burn — Q1 2026 PR · SEC 6-K Ex. 99.1.
Convention Terminal-value proxy on procedure peak (not drug years-on-therapy). Device/oncology M&A ~3–6× peak sales — see comparables table.
Assumption Residual platform optionality in $M (not $B — do not confuse with SLS-scale platform). Commercial bull (ops) defaults to $8M max so platform does not dominate ops. Japan H&N is a separate contribution line above. Technology page
Emerging Separate bucket — JRPR 2024 cites abscopal / immuno-combo as theoretical, not pivotal proof (Kim & Sung). Like ASTS-style optionality, not ops revenue.
Outputs
Risk-adj EV
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Risk-adj equity $/sh
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Risk-adj peak sales
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Cash runway cash burn
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EV contribution by indication
Indication
Peak $M/yr
P(s)
EV $M
Comparables assumption
Comp
Multiple
Note
Tag
Community DD reality checks
Themes from r/DRTS_Stock and biotech retail forums cross-checked against IR, ClinicalTrials.gov, and SEC filings — not endorsements.
Theme
Verdict
Tag
Notes
Bear case honest
Short/skeptic arguments cross-checked against SEC filings, FDA device precedent, and company disclosures — not a recommendation to short.
Risk
Verdict
Tag
Notes
Limitations: Sum-of-parts only — no DCF, no probability-weighted NPV by year, no debt beyond cash stub. Linked skin P(s) applies a PMA haircut to educational trial co-primary success — not approval certainty. P(success) sliders are independent per indication unless linked. Dilution stress is manual (no auto-issue from F-3/ATM capacity). Comparables are illustrative, not a trading comp set. Bear case table summarizes community/ filing risks — not probability-weighted.
References · Valuation
Alpha Tau Q1 2026 PR — net loss $22.9M, financial expense $9.6M (warrants), cash $80.2M
Fact Ra-224 seeds implanted in tumor release alpha-emitting daughters that diffuse ~mm-scale, delivering high-LET DNA damage locally (PubMed 31759075).
Educational schematic Interactive modules below explain α penetration, LET, decay chain, hypoxia, and seed placement. Not clinical treatment planning or Monte Carlo dosimetry — see Explain tab for methodology links.
Sim A Penetration depth in tissue
Fact α particles from Ra-224 daughters travel ~40–70 μm in water/tissue (CSDA); β and γ/X-ray penetrate mm–cm. Model Log-scale bars + animated tracks from a seed — slider varies α energy (MeV).
Fact Click each daughter or step through the chain. Half-lives span milliseconds to days — this is a sequence of isotopes, not a clock. Half-lives from NNDC.
Step 1 of 7: Ra-224
→→→→→→
Ra-224t½ 3.66 d (NNDC)
Decay modeα
Parent fixed in the seed; continuously feeds the daughter chain over days of treatment.
Stays in the seed — source of the local α dose cloud.
Fact Mean lethal dose D₀ (Gy) from exponential survival fits: lower D₀ = more radiosensitive to α particles. Values below are compiled in an independent peer-reviewed review (Kim & Sung, J. Radiat. Prot. Res. 2024) from primary in vitro studies — educational only, not clinical response rates.
Educational Cell-line D₀ does not prove clinical efficacy in that histology. REGAIN interim n=3 remains feasibility only.
Fact Macroscopic α dose in DaRT is computed from diffusion-leakage (DL) transport of Ra-224 daughters, not from external-beam planning alone. Individual α tracks remain ~40–70 μm; the therapeutic cloud is mm-scale from daughter diffusion.
peer-reviewed modelingArazi et al. Phys Med Biol 2010 — foundational DL / CSDA range framework (Alpha Tau–affiliated program).
peer-reviewed modelingHeger, Roy, Dumančić & Arazi, Med Phys 2023 (PMID 36464914) — Part I: single-seed 1D/2D solutions; finite line-source approximations underestimate dose vs full 2D; recommends TG-43-style lookup tables for planning. Alpha TAU–funded; Ben-Gurion group.
peer-reviewed modelingKorotinsky & Arazi, Phys Med Biol 2026 — microdosimetry Part I: broad nucleus-size distributions alter survival/TCP vs uniform-cell assumptions; does not revise the ~40–70 μm α track range. Ben-Gurion / Arazi group (Alpha Tau–affiliated modeling lineage).
peer-reviewed reviewKim & Sung, JRPR 2024 — independent outside review of DaRT dosimetry (DL models, Heger/Zhang FEM, MC studies) and biology. Not an Alpha Tau publication.
Independent review themes (JRPR — sourced, not overclaimed)
Fact High LET → complex DSB, reduced oxygen dependence vs photons (mechanism consensus; not a new clinical proof).
Fact Clinical planning in early trials often used a standardized ~10 Gy prescription from models — JRPR calls this planning approach rudimentary and urges image-based, more sophisticated planning, especially near bone/teeth.
Fact Reported local toxicities (pain, erythema, swelling, mild ulceration) are generally described as tolerable in published cohorts; long-term multicenter toxicity follow-up still needed.
Emerging / theoretical Abscopal effect and immune modulation: case-level and preclinical signals (e.g. Bellia case report; combo with checkpoint blockade in mice). Not proven pivotal clinical efficacy for immunotherapy combinations.
Limit JRPR does not prove registrational efficacy across indications — it synthesizes modeling and early clinical feasibility literature.
Sources: Kim & Sung JRPR 2024 Summary & Discussion · Heger et al. Med Phys 2023 · Korotinsky & Arazi Phys Med Biol 2026 · Arazi 2010. Distinguish Arazi-group modeling (Alpha Tau–affiliated) from independent JRPR review.
Alpha (DaRT)
High LET, ~40–70 μm α track, oxygen-independent mechanism — spares distant organs when seeds placed correctly.
Beta / Gamma (EBRT)
Lower LET, mm–cm penetration — standard external beam; hypoxic regions less sensitive.
Educational schematic only. Does not compute patient-specific dose, prescription, or treatment-planning metrics. Uncertainty in α range ±~20% by energy and tissue composition. Arazi-group papers are peer-reviewed modeling from an Alpha Tau–affiliated program; Kim & Sung (JRPR) is an independent review and does not prove clinical efficacy.
Honesty check: REGAIN interim n=3 local control does not prove systemic GBM control or OS benefit. Do not extrapolate skin SCC FIH CR rate to ReSTART pivotal without discount. In vitro D₀ variance is not a clinical ORR forecast. Abscopal / immuno-combo claims remain emerging/theoretical unless a pivotal trial proves them.