Could Radioligand Therapy Move Earlier in Prostate Cancer Treatment?

Reviewed by Ann Dietrich, MD, FAAP, FACEP 

A few years ago, that question would have sounded aspirational. Now it sounds practical. Radioligand therapyno longer is a late-stage concept that exists mostly in trial presentations and referral-center discussions. In prostate cancer, it already has a defined place in routine care, and the real debate has shifted from whether it works to how early in the disease course it belongs. The answer, at least today, is that it already has moved earlier once, and it may keep moving, but each step forward raises a different clinical standard. In late-line metastatic castration-resistant prostate cancer (mCRPC), showing activity was enough to change the conversation. Earlier in the disease course, the bar is higher. The treatment must prove not just that it can hit prostate-specific membrane antigen, but that using it sooner improves outcomes enough to justify exposing better-performing, longer-living patients to a radiopharmaceutical earlier in their journey.  

That distinction matters because “earlier” is not one thing. Earlier can mean before taxane chemotherapy in metastatic castration-resistant disease. It can mean alongside androgen deprivation therapy and an androgen receptor pathway inhibitor (ARPI) for patients with metastatic hormone-sensitive prostate cancer (mHSPC). It can mean oligometastatic recurrence, where the goal is to control limited disease and delay broader systemic escalation. Or it can mean a neoadjuvant strategy in high-risk localized prostate cancer, before surgery or radiation. These are very different populations, with different goals, different tolerances for toxicity, and very different levels of evidence. The better question is not simply whether radioligand therapy can move earlier in prostate cancer treatment. It is where earlier use already is justified, where it looks promising, and where the field still needs to slow down and prove more.  

Why this question matters now 

The momentum behind earlier radioligand therapy is not hard to understand. In advanced prostate cancer, sequence matters. Many patients do not receive every active therapy available to them because they decline clinically before later lines of treatment can be delivered. That is part of the logic behind moving effective agents forward in many solid tumors, and prostate cancer is no exception. The March 28, 2025, Food and Drug Administration (FDA) expansion of lutetium Lu 177 vipivotide tetraxetan (Pluvicto) made that idea concrete by extending the U.S. indication to adults with prostate-specific membrane antigen (PSMA)-positive mCRPC who already have received ARPI therapy and are considered appropriate to delay taxane-based chemotherapy. In other words, radioligand therapy did not just inch forward conceptually. It moved into an earlier, clinically meaningful position in the treatment sequence.  

That earlier move was not based on a vague sense that the drug “ought to work better sooner.” It was based on PSMAfore, a randomized Phase III study in taxane-naive mCRPC. The FDA summary reports a median radiographic progression-free survival of 9.3 months with lutetium Lu 177 vipivotide tetraxetan vs. 5.6 months with an ARPI switch (hazard ratio [HR], 0.41). The updated 2026 European Association of Urology (EAU) guideline cites a later analysis with median radiographic progression-free survival of 11.60 months vs. 5.59 months and notes that overall survival was not statistically different, in part because more than 60% of patients in the control arm crossed over to receive the radioligand after progression. That combination(strong progression benefit and heavily crossover-confounded survival) is exactly the kind of pattern that tends to push a drug forward in sequence before every academic argument has fully settled.  

Just as important, the current U.S. label still limits  lutetium Lu 177 vipivotide tetraxetan to PSMA-positive mCRPC. As of the current labeling available in April 2026, it is indicated for adults with PSMA-positive mCRPC who have been treated with ARPI therapy and are either appropriate to delay taxane chemotherapy or already have received prior taxane chemotherapy. That means the most provocative part of this conversation, use in metastatic hormone-sensitive disease or even earlier states, remains investigational rather than standard in the United States right now.  

Where radioligand therapy sits today 

The established foundation remains metastatic castration-resistant disease. The original FDA approval in March 2022 was based on the VISION study, which enrolled men with progressive PSMA-positive mCRPC after at least one ARPI and one or two prior taxane regimens. In that study, lutetium Lu 177 vipivotide tetraxetan plus best standard of care improved median overall survival from 11.3 months to 15.3 months (HR, 0.62), and improved radiographic progression-free survival. The EAU continues to treat Llutetium - 177 PSMA-617 as a life-prolonging option in mCRPC, and its 2026 treatment chapter places radioligand therapy squarely among the active systemic agents clinicians should consider when sequencing therapy.  

That point is worth pausing to consider because it shapes the whole “move earlier” debate. Radioligand therapy is not trying to move from experimental irrelevance into mainstream care. It already has cleared that hurdle. The question now is whether it should be used when disease burden is lower, performance status is better, competing therapies are more numerous, and the long-term consequences of treatment matter more. Those are different standards. A therapy that clearly benefits heavily pretreated mCRPC still may need much stronger evidence before it is used routinely in mHSPC or high-risk localized disease. The earlier the setting, the less room there is for uncertainty about selection, durability, and cumulative toxicity.  

There also is a useful lesson in the comparative data. The Phase II TheraP trial, as summarized by the EAU, randomized highly selected men with mCRPC after docetaxel to lutetium  Lu 177 vipivotide tetraxetan or cabazitaxel, using both PSMA positron emission tomography (PET) and fluorodeoxyglucose (FDG) PET for enrichment. The radioligand improved prostate-specific antigen (PSA) response rates, 66% vs. 37% by intention to treat, but overall survival was similar, 19.1 months vs.19.6 months. That does not diminish the treatment. It highlights something more important for earlier use: Better response or progression data do not automatically settle the entire sequencing question. Earlier use must compete not with “nothing left,” but with credible alternatives.  

Why a PSMA PET scan matters before radioligand therapy 

Radioligand therapy in prostate cancer is inseparable from imaging. A PSMA PET scan is not just a staging adjunct. It is the gatekeeper for treatment selection. The current lutetium Lu 177 vipivotide tetraxetan label instructs clinicians to select patients using gallium Ga 68 gozetotide (Locametz) or another approved PSMA PET product based on tumor PSMA expression. The original FDA approval language was even more explicit: Patients in VISION were selected based on PSMA-positive lesions on PET, and they were excluded if they had lesions above certain size thresholds with uptake less than or equal to normal liver. That matters because it means radioligand therapy is not simply given for prostate cancer. It is given for a PSMA-imaged biological phenotype of prostate cancer.  

That requirement becomes even more important if radioligand therapy moves earlier in treatment. In late-line mCRPC, clinicians may accept a certain amount of imprecision because the treatment need is urgent, and the alternatives are fewer. In earlier disease, the selection problem gets harder, not easier. A patient may have lower-volume disease, mixed biology, or lesions that are visible on other imaging but only modestly avid on a PSMA PET scan. The joint European Association of Nuclear Medicine/Society of Nuclear Medicine and Molecular Imaging (EANM/SNMMI) guideline notes that PSMA PET can identify target-positive disease in most clinically significant prostate adenocarcinomas, but it also emphasizes that practitioners should identify patients with the highest potential to benefit and that ongoing Phase III trials are needed to define additional clinical situations. In other words, PSMA positivity is necessary, but it is not the same thing as guaranteed benefit.  

The TheraP experience reinforces that point. Patients in this study were selected not only with PSMA PET but also with FDG PET, and the randomized comparison favored radioligand therapy for PSA response while later analyses showed that outcomes were poorer in men with low PSMA expression or FDG-discordant disease. That is an important caution for the “give it earlier” impulse. If radioligand therapy expands into lower-volume or less treatment-resistant states, the field may need more, not less, biomarker discipline. A PSMA PET scan will remain central, but the deeper question is which PSMA-positive patients are the right PSMA-positive patients.  

Earlier use in metastatic castration-resistant disease is already here 

VISION established the class 

The reason clinicians take the earlier-line question seriously is that VISION already established the class effect in a hard population. That trial showed that delivering beta radiation directly to PSMA-expressing metastatic deposits can translate into a survival advantage in mCRPC. It also came with a toxicity profile that was significant but familiar: fatigue, dry mouth, nausea, anemia, cytopenias, and renal considerations. The FDA also noted that the VISION follow-up was not long enough to fully capture late radiation-associated toxicities. That is not a reason to avoid the drug in advanced mCRPC, but it is absolutely relevant when discussing movement into earlier settings where patients may live much longer after exposure.  

Another subtle but important point from VISION is that the trial did not simply prove a target. It proved a treatment model. Patients were selected with a PSMA PET scan, treated with a fixed radioligand schedule, and managed within the framework of standard systemic therapy. That model is exactly what later studies have been trying to bring forward. When people ask whether radioligand therapy could move earlier in prostate cancer treatment, what they are really asking is whether the VISION model can be transplanted into settings where the disease is less refractory and the treatment intent is more ambitious.  

PSMAfore changed the timing 

If VISION proved the class, PSMAfore changed the sequence. The FDA expansion in March 2025 formally allowed lutetium Lu 177 vipivotide tetraxetan to be used after ARPI therapy and before taxane chemotherapy in selected patients with PSMA-positive mCRPC. The EAU’s 2026 guideline is blunt about what that means clinically: In patients progressing on a first ARPI for mCRPC, an ARPI-to-ARPI switch has limited value, and based on the radiographic progression-free survival benefit, lutetium Lu 177 vipivotide tetraxetan would be preferred to an ARPI switch. That is not a minor adjustment. It means radioligand therapy already has crossed from rescue therapy to a more strategic, earlier-line option within metastatic castration-resistant disease.  

The PSMAfore results also are instructive for how movement to earlier in treatment is likely to happen in the future. The treatment did not have to beat every existing option in every endpoint to justify earlier use. It had to outperform a weak control strategy that many clinicians already viewed skeptically (sequential ARPI use after prior ARPI progression) and do so with a manageable safety profile. That makes sense in pre-taxane mCRPC. It becomes more complicated in metastatic hormone-sensitive disease, where the comparator is not a tired ARPI switch but front-line combinations that already prolong survival. That is why movement from post-taxane to pre-taxane mCRPC felt achievable, while movement from mCRPC into mHSPC remains the far more consequential leap.  

The real next step is metastatic hormone-sensitive disease 

UpFrontPSMA provided the proof of concept 

The first serious proof of concept that radioligand therapy might have a role before castration resistance came from UpFrontPSMA. In this randomized Phase II trial in de novo high-volume mHSPC, sequential lutetium-177 PSMA-617 followed by docetaxel improved antitumor activity compared with docetaxel alone and did so without increased toxic effects, according to the Lancet Oncology report. That does not make it practice-changing on its own, but it matters because it showed that bringing radioligand therapy into hormone-sensitive disease was not purely theoretical. It could be operationalized in a population that was earlier in course, more treatment-responsive, and still receiving intensification with standard systemic therapy.  

The deeper significance of UpFrontPSMA is conceptual. It suggests that earlier use may work best not as a simple substitution, but as part of intensification. That fits the biology of modern mHSPC, where the standard approach already is combination treatment, typically androgen deprivation therapy (ADT) plus an ARPI, with or without docetaxel, depending on disease burden and clinical context. In that world, radioligand therapy is unlikely to earn a place by merely being active. It must show that adding targeted radiation to already effective systemic backbones produces clinically meaningful benefit without making the whole regimen unmanageable. UpFrontPSMA was a first signal that this may be possible.  

PSMAddition brought Phase III momentum 

The biggest reason the earlier use question is taken so seriously in 2026 is PSMAddition. This Phase III trial tested lutetium-177 vipivotide tetraxetan plus standard of care, defined as ADT plus an ARPI, vs. standard of care alone in PSMA-positive mHSPC. At the European Society for Medical Oncology ESMO Congress 2025, Novartis reported that the study met its primary endpoint, with a 28% reduction in the risk of radiographic progression or death (HR, 0.72), and a favorable early overall survival trend (HR, 0.84), with follow-up ongoing for maturity. The company also reported delayed progression to mCRPC (HR, 0.70). Annals of Oncology indexed the presentation as the first Phase III trial showing a significant radiographic progression-free survival benefit for radioligand therapy in mHSPC.  

That is a major development, but it needs to be interpreted with some discipline. First, these are trial data in a carefully selected PSMA-positive population, not a blanket endorsement for all mHSPC. Second, as of the current U.S. label available in April 2026, lutetium Lu 177 vipivotide tetraxetan is not yet approved for mHSPC. Third, early movement into hormone-sensitive disease creates a much tougher value equation. ADT plus ARPI already works. Many patients also receive docetaxel. The standard radioligand has to surpass no longer is therapeutic scarcity. It is an increasingly effective front-line ecosystem. A positive radiographic progression-free survival result is important, but most oncologists still will want mature overall survival, deeper quality-of-life interpretation, and clearer sequencing guidance before declaring the job done.  

There also is a subtle patient-selection issue inside PSMAddition. The trial enrolled men with PSMA-positive disease determined by PSMA PET, and its treatment strategy effectively assumes that image-selected target expression remains meaningful in the hormone-sensitive setting, even while patients are receiving ADT and ARPI therapy that may themselves alter PSMA biology and radiosensitivity. That is exactly the kind of translational nuance that makes earlier movement so interesting. It may turn out that earlier disease is more radiosensitive and more targetable. It also may turn out that the best timing, the best imaging thresholds, and the best companion systemic partners are narrower than a broad positive headline suggests.  

Oligometastatic disease may be the most interesting test case 

One of the most intriguing earlier-use settings is not newly diagnosed metastatic disease at all. It is oligometastatic prostate cancer, especially recurrent hormone-sensitive disease after prior definitive therapy. This setting is attractive because the tumor burden is limited, PSMA-targeted delivery may be more efficient, and the therapeutic goal often is to delay long-term systemic escalation rather than simply palliate later-stage disease. In that sense, oligometastatic disease may be the purest place to test whether radioligand therapy can change the natural history of prostate cancer earlier, because the disease state still is narrow enough that a targeted systemic radiopharmaceutical plausibly could reset the trajectory.  

The first randomized Phase II signal in this space is encouraging. A Lancet Oncology report on  lutetium Lu 177 vipivotide tetraxetan in high-risk oligometastatic hormone-sensitive prostate cancer described the study as the first randomized Phase II trial BULLSEYE trial of its kind and reported that radioligand therapy delayed disease progression while being well tolerated and maintaining health-related quality of life. That is the kind of result that naturally fuels interest in moving earlier, because oligometastatic patients are exactly the ones in whom clinicians and patients are most motivated to preserve quality of life while postponing broader systemic therapy.  

Still, oligometastatic disease is where the field has to be especially careful not to confuse elegance with certainty. Prostate cancer with one to five PSMA-detected lesions is not a single biological entity. Some patients have truly limited disease. Others have a PSMA PET scan that simply is more sensitive than older imaging and is revealing the visible edge of more widespread biology. That matters because radioligand therapy must compete in this space not just with observation or ADT, but also with metastasis-directed radiotherapy strategies that already are being used to defer escalation. Ongoing studies such as PSMA-DC, which is evaluating lutetium Lu 177 vipivotide tetraxetan in oligometastatic prostate cancer progressing after definitive treatment of the primary tumor, and LUNAR, which is testing lutetium Lu 177 vipivotide tetraxetan before stereotactic body radiotherapy in oligorecurrent disease, are important because they are asking whether systemic targeted radiation adds something distinct to local metastasis-directed care.  

If radioligand therapy truly moves earlier in treatment here, it may be because it solves a problem stereotactic body radiotherapy (SBRT) alone cannot solve. SBRT can sterilize the lesions a PSMA PET scan can see. A radioligand also might treat microscopic PSMA-expressing disease that imaging does not yet reveal. That is the theory. The challenge is proving that the additional systemic exposure is worth it in patients who otherwise may enjoy a long, relatively low-symptom course. This is why oligometastatic prostate cancer may end up being the most intellectually appealing setting for earlier radioligand therapy, and one of the hardest in which to change standard practice.  

Localized high-risk disease is the boldest move, and the least mature 

If moving from post-taxane mCRPC to pre-taxane mCRPC was a logical extension, and moving into mHSPC is a major but defensible escalation, bringing radioligand therapy into localized high-risk prostate cancer is the boldest version of the idea. Here the rationale is straightforward: High-risk localized disease often fails because local treatment alone does not address occult micro metastatic burden, and neoadjuvant systemic therapy could, in theory, downstage the primary tumor while also treating disease beyond what imaging can see. Radioligand therapy is attractive in that context because it targets PSMA expression systemically while still delivering substantial radiation to the known tumor.  

However, the clinical evidence still is early. LuTectomy, a Phase I/II study of neoadjuvant lutetium Lu 177 vipivotide tetraxetan before radical prostatectomy in high-risk localized or locoregionally advanced disease, reported that up to two cycles could be administered safely, delivered targeted radiation doses to tumor-affected tissues, and generally were well tolerated. A separate study of neoadjuvant lutetium-177 PSMA-I&T before robot-assisted radical prostatectomy NALuPROST trial similarly concluded that the approach was safe and feasible but stated clearly that therapeutic efficacy remains unknown. Those are promising translational results, not practice-defining results. They tell clinicians that earlier use in localized prostate cancer is technically and biologically possible. They do not yet prove that it improves the outcomes that matter most after surgery or radiation.  

This distinction matters more in localized disease than anywhere else. A patient with high-risk localized prostate cancer still may be cured with multimodality conventional treatment. That means the threshold for adding a radioligand is extremely high. The treatment cannot simply be active or safe enough. It must improve pathologic response, metastasis-free survival, or long-term cure-related endpoints in a way that justifies added complexity, radiation exposure, marrow effects, salivary toxicity, and cost. Until that happens, neoadjuvant radioligand therapy in localized prostate cancer should be viewed as an ambitious research strategy, not a near-term routine change in care.  

What still could prevent earlier use from becoming standard 

Selection is more complicated than simple PSMA positivity 

The first barrier is selection. A PSMA PET scan is indispensable, but it is not a magical binary test. The current regulatory framework for lutetium Lu 177 vipivotide tetraxetan requires approved PSMA PET-based selection, and VISION used a specific imaging definition that included both positive lesions and exclusion of certain PSMA-low lesions. TheraP went further by requiring both PSMA PET positivity and absence of unfavorable FDG-discordant disease. That tells us the field already knows a hard truth: Not every PSMA-positive prostate cancer is the same radioligand target. As treatment moves earlier, when clinicians are less willing to overtreat and more focused on maximizing durability, selection standards may have to become even more sophisticated rather than more permissive.  

The second barrier is that imaging positivity does not fully solve tumor biology. Earlier disease still can be heterogeneous. Some tumors show strong PSMA expression and sustained radiographic response. Others have mixed-expression biology, aggressive visceral behavior, or molecular features associated with poor response. The SNMMI/EANM practice guideline explicitly notes that patient selection should aim to identify those with the highest potential to benefit and discusses predictive factors beyond imaging alone. That matters because the temptation with a PSMA PET scan is to assume that a visible target equals a suitable target. In reality, earlier radioligand therapy may need a more integrated model that includes imaging phenotype, disease burden, prior therapy, visceral involvement, and, perhaps, circulating biomarkers.  

Long-term toxicity matters more the earlier treatment is used 

The toxicity profile that feels acceptable in late-line mCRPC may feel different in patients expected to live years longer. In VISION, lutetium Lu 177 vipivotide tetraxetan improved survival but was associated with radiation exposure, myelosuppression, renal toxicity, dry mouth, anemia, and other laboratory abnormalities. The FDA also stated that follow-up in VISION was not sufficient to capture late radiation-associated toxicities. That point becomes much more important in mHSPC or localized disease, in which patients may live long enough for late marrow, renal, salivary, or even secondary malignancy questions to matter more than they do in heavily pretreated mCRPC.  

This does not mean radioligand therapy is too toxic to move earlier in treatment. It means the tolerability conversation changes as the disease state changes. In post-taxane mCRPC, clinicians may accept higher uncertainty about late effects because the near-term treatment need is pressing. In metastatic hormone-sensitive disease, in which patients already may do well for years on ADT plus ARPI with or without docetaxel, adding a radiopharmaceutical requires more confidence that the progression benefit is durable, the toxicity is manageable, and the quality-of-life tradeoff is worthwhile. Earlier use magnifies the need for mature follow-up, not just positive interim curves.  

Sequencing and combination strategy still are unsettled 

Another unresolved issue is what earlier use actually is supposed to replace. In pre-taxane mCRPC, the comparator was an ARPI switch, a strategy many clinicians already view as weak after clear ARPI progression. In mHSPC, the comparator (ADT plus ARPI) is far more formidable,  with docetaxel still relevant in selected patients. That means earlier radioligand therapy may need to succeed by combination, not by substitution. UpFrontPSMA and PSMAddition both point in that direction. They do not frame radioligand therapy as a stand-alone early replacement. They frame it as an intensification strategy layered onto effective systemic backbones.  

That raises difficult sequencing questions. Should radioligand therapy be added before docetaxel, after docetaxel, or instead of docetaxel in selected patients? Should it be reserved for high-volume disease, or could lower-volume PSMA-avid disease benefit more? Does earlier exposure make later retreatment more attractive, or does it exhaust one of the most useful options too soon? The EAU already notes growing interest in rechallenge after prior response and relapse in mCRPC, but that is a different conversation from moving the therapy into the front half of the disease course. Earlier use is not just about proving activity. It is about deciding where the therapy belongs in a crowded treatment architecture.  

Logistics and infrastructure still matter 

There also is a more practical barrier: Radioligand therapy is not just a drug, it is a delivery system. The current label requires handling by healthcare providers with specific training and experience in radiopharmaceutical use, and treatment depends on imaging selection, radio pharmacy coordination, infusion infrastructure, radiation safety processes, and multidisciplinary follow-up. Earlier use not only would expand the number of eligible patients, it would increase the pressure on the entire theranostics ecosystem. That matters because access can influence real-world sequencing just as much as efficacy.  

To be fair, the industry has clearly recognized this. Novartis stated at the time of the 2025 pre-taxane approval that it had manufacturing capacity to meet supply needs for the expanded indication. Even so, scaling a radioligand from a late-line niche into a broader earlier-line standard is a different operational challenge. Earlier use is not only a regulatory or scientific question, it is a system question.  

What this means for treatment decisions right now 

In current practice, the most defensible answer is that radioligand therapy already has moved earlier within mCRPC treatment, and clinicians should think of it that way. For PSMA-positive mCRPC after ARPI exposure, before taxane in appropriately selected patients, this no longer is a theoretical future state, it is current U.S. regulatory reality. If the patient is being considered for an ARPI switch after progression on prior ARPI, the field now has strong evidence that a radioligand usually is the more compelling alternative.  

However, beyond that, earlier use still belongs mainly in the language of informed anticipation and clinical trials. Metastatic hormone-sensitive disease is the clearest next frontier because Phase III data are now positive for radiographic progression-free survival, but the treatment is not yet reflected in the current U.S. label, and overall survival remains immature. Oligometastatic disease is scientifically appealing and eventually may become a real niche for targeted systemic radiotherapy, but the evidence is not yet mature enough to standardize it outside trial-driven or highly selective practice contexts. High-risk localized disease is even earlier in development.