On June 1, 2026 Telix Pharmaceuticals Limited (ASX: TLX, NASDAQ: TLX, "Telix") reported the oral presentation of Part 1 safety, dosimetry and pharmacokinetics data from the ProstACT Global Phase 3 Study of TLX591-Tx (lutetium-177 (177Lu) rosopatamab tetraxetan), in metastatic castration-resistant prostate cancer (mCRPC). The late-breaking data were presented today at the 2026 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting in Chicago, Illinois by study Principal Investigator Pedro C. Barata, MD, Medical Oncologist, University Hospitals Seidman Cancer Center and Associate Professor of Medicine, Case Western Reserve University of School of Medicine, Cleveland, Ohio.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Results demonstrated that TLX591-Tx, Telix’s lead prostate-specific membrane antigen (PSMA) targeted lutetium rADC therapy candidate, has an acceptable safety and tolerability profile when administered with standard of care (SoC) therapies in mCRPC, with no new safety signals observed.

ProstACT Global is an international, multi-center, randomized Phase 3 trial comparing TLX591-Tx, administered as two doses, 14 days apart with SoC (abiraterone, enzalutamide or docetaxel) versus SoC alone. The study is designed to reflect real-world clinical practice2 and enrolls PSMA-positive mCRPC patients previously treated with one androgen receptor pathway inhibitor (ARPI).

Patients were monitored for treatment-emergent adverse events and underwent serial SPECT/CT3 imaging after TLX591-Tx administration for dosimetry and blood sampling for pharmacokinetics. The primary endpoint was safety and tolerability of TLX591-Tx + SoC. Key secondary endpoints were pharmacokinetics and radiation dosimetry.

Results: Data from 36 patients (baseline median PSA4: 18.18 ng/mL) who received any study treatment were included: Cohort 1 (11 patients), TLX591-Tx + abiraterone; Cohort 2 (11 patients), TLX591-Tx + enzalutamide; Cohort 3 (14 patients), TLX591-Tx followed by docetaxel.

Safety and tolerability

Acceptable safety profile observed across all combination cohorts, tolerability of TLX591-Tx consistent with prior studies.
All 36 patients received both doses of TLX591-Tx per protocol.
No new safety signals identified.
Almost all treatment-emergent non-hematologic events were Grade 1–2, primarily fatigue (53%), nausea (28%) and dry mouth (25%).
Hematologic events were transient and manageable: Grade 3 thrombocytopenia (14%) and neutropenia (22%), and Grade 4 thrombocytopenia (31%) and neutropenia (25%) events were in line with the profile expected for this class of therapy and extent of disease.
Dosimetry and pharmacokinetics

Radiation exposure to key organs was well below established safety limits5.
Highest absorbed dose observed in liver (range, 1.62-5.08 mGy/MBq), with lower doses received by kidneys (0.336-0.961 mGy/MBq) and salivary glands (0.001-0.104 mGy/MBq).
Lesion dosimetry confirmed uptake across tumor sites and across all cohorts.
Pharmacokinetics demonstrated sustained activity at Day 15, corroborated by imaging which demonstrated prolonged tumor retention.
No evidence of drug-drug interactions impacting TLX591-Tx targeting, distribution or clearance.
Telix has initiated Part 2, a 2:1 randomized treatment expansion, in jurisdictions where regulatory approvals have been obtained. Engagement is underway with the United States (U.S.) Food and Drug Administration (FDA) to discuss Part 1 data and seek an Investigational New Drug (IND) amendment to progress Part 2 in the U.S.

Pedro C. Barata, MD, stated, "These results support the feasibility of administering TLX591-Tx alongside current standard-of-care therapies for mCRPC, including ARPIs. Imaging demonstrated sustained tumor retention through day 15, while dosimetry analyses showed radiation exposure below established safety thresholds and limited dose to key organs. Hematologic adverse events were generally consistent with those expected in this patient population and therapeutic class and were transient in most cases. Overall, the safety, dosimetry, and tumor-targeting findings, together with the high treatment compliance observed in this study, support further evaluation of this approach, in the randomized phase of the trial."

David N. Cade, MD, Group Chief Medical Officer, Telix added, "Despite meaningful advances in clinical practice, mCRPC remains a disease where patients urgently need additional first and second-line options. These Part 1 results, presented today at ASCO (Free ASCO Whitepaper), build on prior clinical findings and further support our view that TLX591-Tx in combination with contemporary standard of care has the potential to become a new treatment option for this aggressive disease."

The ASCO (Free ASCO Whitepaper) presentation abstract can be found here.

About ProstACT Global

ProstACT Global (ClinicalTrials.gov ID: NCT06520345) is an international, multicenter trial in two parts: Part 1, safety and dosimetry lead-in with 36 patients (complete); and Part 2, 2:1 randomized global expansion with an overall target enrollment of approximately 490 patients. Eligible patients must have confirmed progressive mCRPC assessed with a 68Ga-PSMA-11 PET6 imaging agent (such as Illuccix, kit for the preparation of gallium-68 (68Ga) gozetotide injection, or Gozellix, kit for the preparation of gallium-68 (68Ga) gozetotide injection) following prior treatment with one ARPI.

The antibody approach demonstrates different targeting and pharmacology to that observed in other PSMA-targeted small molecule radioligand therapies (RLT). In contrast to these therapies7, collective long-term follow-up of patients administered with TLX591-Tx has not observed significant acute or delayed kidney toxicity, as the agent is primarily cleared through the liver, a comparatively radioresistant organ, instead of the kidneys8. Due to its large molecular weight, TLX591-Tx also demonstrates minimal salivary and lacrimal gland uptake, reducing dry mouth and dry eyes, common adverse effects of existing PSMA-targeted RLTs9.

Additional information on the Phase 3 ProstACT Global study can be found at: View Source

(Press release, Telix Pharmaceuticals, JUN 1, 2026, View Source [SID1234666347])

On June 1, 2026 Foundation Medicine, Inc., a global, patient-focused precision medicine company, reported that it has received approvals from the U.S. Food and Drug Administration (FDA) for FoundationOneCDx and FoundationOneLiquid CDx to be used as companion diagnostics for Pfizer’s TALZENNA (talazoparib) in combination with XTANDI (enzalutamide) to identify patients with homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer (mCRPC). TALZENNA is first and only PARP inhibitor approved for use with an existing standard of care (XTANDI) for adult patients with both BRCA mutated and non-BRCA HRR gene-mutated mCRPC.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Prostate cancer is the second most common cancer in men, with approximately 1 in 8 diagnosed during their lifetime.2 mCRPC occurs when prostate cancer grows and spreads to other parts of the body despite hormone therapy that lowers testosterone. HRR gene mutations are present in approximately 20-30% of patients with mCRPC.3 While treatment options have expanded in recent years, patients with mCRPC often continue to face poor prognosis and limited treatment options.4

"Every patient deserves clear, personalized answers when it comes to their treatment plan, but one-size-fits all approaches do not work for everyone. As more targeted therapies become available to treat mCRPC, it is incredibly important to have high-quality tissue- and blood-based companion diagnostics available to best inform personalized treatment plans for each unique patient," said Todd Druley, M.D., Ph.D., Chief Medical Officer at Foundation Medicine. "These two approvals further strengthen Foundation Medicine’s leadership in companion diagnostics and underscore the critical role of comprehensive genomic profiling in connecting patients with targeted treatment options."

Foundation Medicine is the only company with an FDA-approved portfolio of tissue and blood-based comprehensive genomic profiling tests.5 With this most recent approval, Foundation Medicine has nine FDA-approved companion diagnostic indications for prostate cancer, and over 100 approved CDx indications in total, three times more than any other comprehensive genomic profiling company.1,6

"Too many prostate cancer patients still can’t access the biomarker tests that should guide their treatment, not because the tests don’t exist, but because access isn’t consistent or equitable," said Courtney Bugler, President and CEO of ZERO Prostate Cancer. "Biomarker testing gives patients and their families the clarity they need to understand their diagnosis and make informed decisions about care. Every person deserves access to personalized treatment information, regardless of their doctor, their diagnosis, or their ZIP code."

(Press release, Foundation Medicine, JUN 1, 2026, View Source [SID1234666346])

On June 1, 2026 Sumitomo Pharma America, Inc. (SMPA) reported clinical data from its ongoing first-in-human Phase 1/2 trial of SMP-3124LP (NCT06526819). SMP-3124LP is a structurally distinct, investigational, selective checkpoint kinase 1 (CHK1) inhibitor delivered via a PEGylated liposome formulation. Designed with the specific goal of treating malignancies characterized by high replication stress, these findings were presented as a poster at the 2026 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

"Historically, the development of CHK1 inhibitors has been hampered by significant low blood counts and a narrow therapeutic window, which has limited their clinical utility for patients," said Timothy A. Yap, MBBS, PhD, Professor of Investigational Cancer Therapeutics at The University of Texas MD Anderson Cancer Center and lead investigator of the study. "By using this liposomal delivery method, we are attempting to address the primary obstacles that have previously stalled the CHK1 inhibitor mechanism of action. For patients who have already navigated multiple lines of therapy, this approach may offer the potential for meaningful clinical benefit and disease control without the overwhelming burden of side effects common to older therapies."

Encouraging antitumor activity in heavily pretreated malignancies
The phase 1 part of the study enrolled 61 patients with selected advanced solid tumors across four intravenous (IV) doses: 20, 40, 60, and 90 mg/m2 given every two weeks. The study population was heavily pretreated, with 37.7% of participants treated with more than four prior lines of therapy. SMP-3124LP demonstrated promising signals of antitumor activity (as of April 03, 2026.)

Among the 56 efficacy-evaluable patients, the study reported a 48.2% disease control rate (DCR). This included five RECIST v1.1 partial responses (PR) and 22 patients with stable disease (SD). The clinical significance of these results is underscored by responses in difficult-to-treat cancers. Partial responses were observed in 2 patients with platinum-resistant ovarian cancer (PROC), 2 with squamous cell carcinoma of the anus (SCCA), and 1 with colorectal cancer harboring an FBXW7 mutation (this mutation is linked to poorer outcomes). Furthermore, 2 additional PROC patients achieved stable disease with tumor shrinkage of 20% or more, including one patient who experienced a -88% cancer antigen-125 (CA-125) response.

Preliminary results show liposomal delivery widened the therapeutic window with a manageable safety profile
The Phase 1/2 results show that SMP-3124LP was generally well tolerated with a manageable safety profile. No dose-limiting toxicities (DLTs) were observed at the lower dose levels of 20 or 40 mg/m2. While DLTs including Grade 4 thrombocytopenia and Grade 3 febrile neutropenia were noted at higher doses (60 and 90 mg/m2), the blood-related side effects (low blood counts) were generally transient and did not lead to any treatment discontinuations.

These findings suggest the liposomal delivery system may minimize drug exposure to healthy tissues while optimizing delivery to tumors. Infusion-related reactions (IRR), reported in 41% of patients, were all Grade 1/2 and manageable through standard supportive care or adjusted infusion rates. Additionally, pharmacokinetic data validated the therapeutic approach, long half-life (24-28 hr), and low volume of distribution (2.00-2.67 L) are consistent with liposomal formulation. Dose-proportional increases in exposure were observed across all levels tested.

"We are proud to present our first-in-human data for SMP-3124LP at ASCO (Free ASCO Whitepaper)—where the most rigorous advancements in oncology are shared—as it reinforces our focus on addressing some of the most persistent challenges in cancer treatment," said Tsutomu Nakagawa, Ph.D., President and Chief Executive Officer of SMPA.

"With SMP-3124LP, we are developing a technology platform at SMPA based on liposomal delivery of targeted therapies in an effort to maximize the therapeutic window and minimize toxicities," said Jatin Shah, M.D., Chief Medical Officer, Oncology, SMPA. "These are the first data in this first-in-human study of SMP-3124 where we have demonstrated the potential ability to deliver selective CHK1 inhibition with less myelosuppression, which has been the major AE limiting the ability to target CHK1 directly to the tumor while sparing the patient’s healthy cells. These data are a reflection of our efforts toward realizing sustainable and effective therapeutic options for those facing the complexities of difficult-to-treat cancers, including advanced solid tumors."

CHK1 is an essential enzyme in the DNA damage response pathway that helps cancer cells repair their DNA to survive under high replication stress. While blocking CHK1 has long been a goal for oncologists, prior inhibitors were often toxic to healthy bone marrow, limiting their clinical utility. SMP-3124LP seeks to overcome this hurdle by using liposomal technology to widen the therapeutic window (the gap between an effective dose and a toxic one). This advancement may potentially unlock CHK1 inhibition for patients with few remaining treatment options.

Presentation Details

Abstract Number: 3081
Abstract title: First data disclosure from the first-in-human phase 1/2 trial of SMP-3124LP, the first investigational pegylated liposome CHK1 inhibitor, in patients with selected advanced solid tumors
Session title: Developmental Therapeutics—Molecularly Targeted Agents and Tumor Biology
About SMP-3124LP
SMP-3124LP is a structurally distinct, investigational, selective checkpoint kinase 1 (CHK1) inhibitor delivered via a PEGylated liposome formulation. CHK1 is a key regulator of the DNA damage response; SMP-3124LP is designed with the goal of inhibiting this protein to induce DNA damage and promote apoptosis (cell death) in cancer cells with high replication stress. The use of liposomal technology may potentially widen the therapeutic window by maximizing drug delivery to tumors while minimizing exposure to healthy tissues, potentially reducing treatment emergent adverse events (TEAEs).

(Press release, Sumitomo Pharmaceuticals, JUN 1, 2026, View Source [SID1234666345])

On June 1, 2026 Qurient Co., Ltd. (KRX: 115180) reported that the first patient has been dosed in a Phase 2 clinical study evaluating mocaciclib (Q901) in combination with fulvestrant for treatment of hormone receptor-positive (HR+) breast cancer. The trial specifically targets patients who have stopped responding to prior treatments containing CDK4/6 inhibitors. Mocaciclib is a highly selective and potent covalent inhibitor of cyclin-dependent kinase 7 (CDK7), developed to address significant unmet medical needs in advanced solid tumors, including treatment-resistant breast cancer.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

The dosing of the first patient with CDK4/6 inhibitor-resistant HR+ breast cancer marks a significant milestone in development of mocaciclib as a new therapeutic option. While CDK4/6 inhibitors combined with endocrine therapy have proven highly effective for treatment of HR-positive, HER2-negative metastatic breast cancer, many patients eventually experience disease progression due to innate non-responsiveness or acquired resistance. Mocaciclib is being investigated as a targeted solution to overcome the refractory conditions through cell cycle control and transcriptional regulation of key refractory mechanisms, such as PTEN-PI3K/AKT pathway activation.

"Dosing the first HR-positive breast cancer patient with mocaciclib is an important step forward in our mission to provide new therapeutic options for patients who have exhausted standard-of-care treatments," said Kiyean Nam, Ph.D., Chief Executive Officer of Qurient. "Because of its unique mechanism of action in cell cycle control and transcriptional regulation, mocaciclib holds promise for patients whose tumors have developed bypass mechanisms to evade CDK4/6 inhibition. We are highly encouraged by our latest findings in CDK7 biology and look forward to translating this science into meaningful clinical outcomes."

Mechanism of Action Rationale in HR+ Breast Cancer

Mocaciclib (Q901) provides a novel therapeutic strategy for HR+ breast cancer by targeting CDK7, a dual-function kinase essential for both cell cycle progression and transcriptional regulation:

Master Regulation of the Cell Cycle (CAK Inhibition): CDK7 acts as the CDK-activating kinase (CAK), responsible for phosphorylating the T-loop of other key cell cycle kinases, including CDK1, CDK2, CDK4, and CDK6. In HR+ breast cancer, resistance to CDK4/6 inhibitors frequently occurs through the loss of retinoblastoma (RB) protein function or the over-activation of the Cyclin E-CDK2 axis. This allows cancer cells to bypass the CDK4/6 blockade and re-enter the S-phase of division. By potently inhibiting CDK7, mocaciclib suppresses the activation of CDK2 and other downstream kinases, effectively shutting down these alternative escape routes and halting tumor proliferation.
Targeted Transcriptional Repression: Beyond cell cycle control, CDK7 is a core component of the transcription factor II H (TFIIH) complex. Mocaciclib selectively disrupts the transcription of heavily relied-upon oncogenic transcription factors (such as MYC and E2F) and suppresses the expression of genes that are activated by the PTEN-PI3K/AKT pathway, effectively neutralizing another mechanism of CDK4/6 inhibitor resistance.
About Mocaciclib (Q901)

Mocaciclib (Q901) is an intravenously administered, highly selective covalent CDK7 inhibitor currently advancing through Phase 1/2 clinical trials (NCT05394103). In addition to its potential as a monotherapy in HR+ breast cancer and other advanced solid tumors, mocaciclib has demonstrated profound synergy in preclinical models when used in combination with Topoisomerase 1 inhibitor-based antibody-drug conjugates (TOP1i-ADCs) and immune checkpoint inhibitors.

(Press release, Qurient Therapeutics, JUN 1, 2026, View Source [SID1234666344])

On June 1, 2026 Foundation Medicine, Inc., a global, patient-focused precision medicine company, and SWOG Clinical Trials Partnerships (SWOG CTP) reported a strategic partnership to advance biomarker-driven research and clinical trials, marking the first collaboration of this nature with a diagnostic company. This partnership builds upon Foundation Medicine’s decade-long collaboration with SWOG Cancer Research Network through the Lung Cancer Master Protocol (Lung-MAP) trial, a multi-drug, multi-arm, biomarker-driven clinical trial for patients with lung cancer.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Foundation Medicine will bring its genomic testing capabilities and extensive expertise as a global leader in companion diagnostic (CDx) approvals, with 100 approved CDx indications, the most of any comprehensive genomic profiling company.1 SWOG CTP’s network of investigators and committees at over 1,300 sites in 47 states, including community hospitals, academic medical centers and National Cancer Institute-designated clinical cancer centers, can collaborate with Foundation Medicine on initiatives including multi-arm platform trials and registrational studies that may lead to future CDx applications. Trials can leverage Foundation Medicine’s robust portfolio of high-quality tests and robust solutions designed for biopharmaceutical partners to support protocol design and uncover multi-omic insights in oncology.

"SWOG CTP shares our commitment to advancing precision oncology by pursuing scientifically rigorous, cutting-edge biomarker-driven research," said Todd Druley, M.D, Ph.D., chief medical officer at Foundation Medicine. "By bringing Foundation Medicine’s deep scientific, regulatory and genomic expertise to SWOG CTP and its broad investigator community, we can help accelerate new breakthroughs in biomarker-driven medicine, moving from discovery to impacting patient care in the clinic with speed and clarity."

"SWOG CTP offers access to an extensive network of sites nationwide and the opportunity to move biomarker-driven science closer to the people who need it most," said Kathy S. Albain, M.D., SWOG vice chair for Clinical Trials Partnerships. "This formalized partnership marks an exciting step forward – one we believe will drive the translation of promising research into meaningful options for patients."

(Press release, Foundation Medicine, JUN 1, 2026, View Source [SID1234666343])