Note: The estimated trial start and completion dates are derived from clinicaltrials.gov. Most trial completion dates are projections and can often be overestimates. Actimab-A is not shown on the timeline, as no trial dates are publicly available.

Below is a summary of the eleven leading assets in the alpha-emitting RLT treatment pipeline:

GEP-NET = gastroenteropancreatic neuroendocrine tumor; mCRPC/CRPC = metastatic/castration-resistant prostate cancer; AML = acute myeloid leukemia; HCC = hepatocellular carcinoma; IV = intravenous; IP = intraperitoneal; 2L = second-line.

Considering the assets above as well as assets in phase 1 of clinical trials outlined below, some key stats on the alpha-emitter landscape:

• Lead indications: Prostate cancer leads the pipeline with 8 assets in active development, followed by solid tumors (7 assets, spanning FAP-α, DLL3, Nectin-4, HER2, and GRPR targets), and GEP-NETs / neuroendocrine tumors (4 assets).
• Company and asset count by region: US - 13 assets across 7 companies. EU - 9 assets across 5 companies. Australia - 3 assets across 2 companies.
• Most Common Isotopes: Actinium-225 dominates the pipeline with 15 of 25 assets, followed by Lead-212 (8 assets). Radium-224 and Thorium-227 are each used in a single asset.

Pipeline Deep Dive

Below is a deep dive of global alpha-emitting radioligand therapy assets furthest along in clinical development:

1. AZD2265 (²²⁵Ac-PSMA) (AstraZeneca)

Trial Progress / Other Milestones

• No clinical trial data is available from VECTRA-01, as the trial very recently registered and kicked off in Q2 2026.^[8]

2. AAA817 (²²⁵Ac-PSMA) (Novartis)

Trial Progress / Other Milestones

• Being developed as the more targeted alpha therapy successor to Novartis's original RLT winner Pluvicto, AAA817 has entered pivotal phase 2/3 trials for metastatic prostate cancer. Novartis's lead indication and trial are targeting second-line treatment of the disease for patients that progress after first-line standard of care Pluvicto (PSMAcTION, NCT06780670)^[11], as well as an additional trial (AcTFirst, NCT06855277) that tests the new therapy in the first-line setting.^[9]
• While no recent trial updates have been provided, Novartis projects FDA regulatory filing for the therapy in 2028.^[12]

3. Actimab-A (Actinium Pharma)

Trial Progress / Other Milestones

• Recent press from Actinium Pharma indicates that Actimab-A is advancing towards a phase 2/3 trial.^[14] However, no such trial is yet registered or kicked off, likely due to lack of available funding; Actinium lists on their pipeline that they are actively seeking a collaborator in order to move forward with this trial.^[15]
• The therapy has multiple phase 1/2 trial failures and postponements which may be contributing to a stall in pivotal trial development: one study was completed in 2018 (NCT02575963)^[16], another was withdrawn (NCT03932318)^[17], and a final phase 1/2 trial records an unknown completion status (NCT03867682)^[18].

4. RYZ101 (²²⁵Ac-DOTATATE) (Bristol Myers Squibb)

Trial Progress / Other Milestones

• Most recent development updates came from a phase 1b portion readout of the ACTION-1 trial in 2024; the focus was on safety and dose-limiting toxicities, where the therapy was generally well-tolerated.^[23][24] The phase 3 portion of the trial is still ongoing.
• BMS is pursuing additional oncology indications, namely SSTR+ HR+/HER2- unresectable metastatic breast cancer, through an ongoing phase 1 trial.^[20]

5. AlphaMedix (²¹²Pb-DOTAMTATE) (Sanofi)

Trial Progress / Other Milestones

• Most recently, phase 2 trial results were released in October 2025, highlighting promising overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS) data.^[26]
• Due to the FDA Breakthrough designation AlphaMedix received in 2024, these phase 2 trial results may be sufficient for pursuing accelerated approval in a high unmet need cancer population.^[28]
• The single-arm trial design, as opposed to a dual-arm trial comparing AlphaMedix against standard of care, may lead to greater difficulty in using this phase 2 data to gain FDA approval.

6. CONV01-α (²²⁵Ac-PSMA) (Convergent Tx)

Trial Progress / Other Milestones

• Convergent recently shared interim data from the phase 2 CONVERGE-01 trial, highlighting radiographic PFS of 8.4 months and favorable tolerability.^[30] Convergent signaled that phase 3 trial design was already underway due to promising interim phase 2 results.

7. Radspherin (Oncoinvent)

Trial Progress / Other Milestones

• Radspherin is not an RLT, as it does not use a targeting ligand. Instead, it remains in the body cavity that it was injected into to create a radiation field,^[32] yielding fewer oncology indications which may benefit from this therapy due to its non-targeting limitations.
• Oncoinvent achieved 50% recruitment in its phase 2 ovarian cancer trial as of June 2026.^[33]
• Previous phase 1 and 1/2a trials in ovarian and colorectal cancer, respectively, were conducted, outlining favorable tolerability and leading to phase 2 advancement.^[32] Both the ovarian and colorectal phase 1 trials achieved positive safety results, suggesting a separate rationale for the company pushing forward with ovarian cancer in a phase 2 trial.^[34][35]
• FDA Fast Track designation was received in 2024.^[36]

8. RYZ801 (²²⁵Ac-GPC3) (Bristol Myers Squibb)

Trial Progress / Other Milestones

• The trial has recently begun and has yet to provide interim results. Most recent data on the therapy is preclinical.^[39]
• RYZ801 has a companion diagnostic molecule, RYZ811.^[38]

9. VMT-α-NET (²⁰³Pb-SSTR) (Perspective Tx)

Trial Progress / Other Milestones

• Interim data from the ongoing phase 1/2a trial was presented at 2026 ASCO. Results primarily focused on primary safety endpoints indicating tolerability, but additional efficacy data based on an n=2 cohort 1 and n=23 cohort 2 patient population was also revealed. The key outcome included 39% of patients responding to treatment, with 7 patients experiencing a deepening of response as classified by investigators.^[42]
• The therapy was granted FDA Fast Track designation in 2022 for treating patients with SSTR2-positive unresectable or metastatic neuroendocrine tumors.^[43]
• Additional trials are being conducted, namely a phase 1 trial in PRRT-refractory neuroendocrine patients (NCT06148636).^[44][45] The company also has its sights set on cancers beyond neuroendocrine tumors, such as meningioma, where SSTR2 is also quite relevant.^[46]
• Like Perspective Therapeutics's other pipeline assets, the core technology is being developed not only as a treatment but also as a diagnostic, in this case utilizing a ²⁰³Pb isotope for imaging purposes.^[45]

10. VMT-01 (²¹²Pb-MC1R) (Perspective Tx)

Trial Progress / Other Milestones

• Most recent trial update outlined 27 patients enrolled as of late 2026, with 13 patients already having received treatment as either monotherapy or combination therapy.^[48] For early interim data, 2 of the 7 patients receiving monotherapy doses showed partial responses.^[48]
• Fast Track designation for treating advanced melanoma was received in 2024.^[49]
• VMT-01 is listed in combination with VMT02; while VMT-01 is being developed both for imaging (²⁰³Pb) and treatment (²¹²Pb), VMT02 is solely used for imaging (⁶⁸Ga) to support subsequent treatment with VMT-01.^[50]

11. PSV359 (²¹²Pb-FAP-α) (Perspective Tx)

Trial Progress / Other Milestones

• Perspective's most recent update on the phase 1/2a trial outlines 17 patients treated across the three trial cohorts. Interim trial results are expected in 2027.^[48]
• The company also announced a collaboration with Merck for developing PSV359 as a combination therapy with pembrolizumab. This will be an amendment to the existing phase 1/2a study.^[53]

Edge Case: Alpha DaRT (Alpha Tau Medical)

Alpha DaRT represents a set of devices designed to deliver an intratumoral injection of Radium-224.^[54] Since the technology is a device platform, a cell-targeting ligand linked to the isotope is not necessary and it technically falls outside of the RLT landscape. It is, however, a directly competing radiopharmaceutical therapy and thus should be taken into consideration when assessing commercial opportunity by any RLT drug developer.

Phase 1 Assets in Development

There are numerous additional RLTs in earlier stages of development. Below are key assets which are in their first human clinical trials and farther out from any potential regulatory approval:

Preclinical Assets in Development

Furthest out from market approval are the preclinical alpha-emitting RLTs. However, this early stage of the pipeline is full of development programs. Data is limited on these programs, as biotechs are increasingly not disclosing details of earlier-stage assets, largely for fear of rapid clinical development times in China that may cause a loss of first-to-market advantage.

Note: Across preclinical and clinical phases 1-3, there are likely additional alpha-emitting assets in global development that weren't captured in this report. While we aim to be as comprehensive as possible, our goal is to focus on the most notable assets that will shape the treatment landscape, and no claims of 100% coverage are made.

Paused or Discontinued Programs

Below are some notable asset development programs that were either paused or permanently discontinued.

Concluding Remarks

The targeted alpha therapy landscape is nearing a first-in-class approval, as multiple assets are in phases 2/3 of clinical trials. Many assets carry breakthrough designations for oncology indications that would let them file for regulatory approval without an expansive global phase 3 effort.

Novartis currently owns the RLT space, with ownership over both therapies currently on the market. Since these are beta-emitters, they also have alpha-emitting assets in the pipeline to compete for this new market. Sanofi, AstraZeneca, and BMS are three of the other big pharma contenders in this space with late clinical-stage assets (Eli Lilly has also made an acquisition to get into the game, but its assets are in earlier phase 1 stages).

Two key emerging biotech players to keep an eye on are Perspective Therapeutics and Telix Pharma. Both companies have numerous assets in the pipeline and are RLT-focused, hoping to carve out a good chunk of this market.

One notable absence is the lack of China-based biotech companies pursuing this space. While there seem to be a couple of Chinese biotechs working on TATs, the number is quite low. There appear to be more Chinese biotechs developing beta-emitters, which is an older and more developed market.

Alpha-emitting RLTs hold the promise for highly targeted and efficacious radiation treatment of many different malignancies. Time will tell if these treatments become a core component of standard of care in oncology.