Fulvestrant is an antiestrogen medication and selective estrogen receptor degrader (SERD) used for hormone receptor-positive advanced or metastatic breast cancer. It is administered by intramuscular injection and is marketed under the brand name Faslodex. Fulvestrant was approved for medical use in the United States in 2002.
Relay Therapeutics reported Q4/FY 2025 results, outlined 2026 milestones for zovegalisib, and held ~$555M in cash. Initial vascular anomaly data and breast cancer triplet data are expected in 2026.
Key oncology developments include a $315 million partnership between Astellas and Vir for the prostate cancer T-cell engager VIR-5500, with updated phase 1 data showing an 82% PSA50 rate. The FDA accepted a filing for Ono Pharmaceuticals' tirabrutinib seeking accelerated approval in primary central nervous system lymphoma. Research findings also identified a new kidney cancer biomarker and showed promising results for the TRK inhibitor repotrectinib and the breast cancer triple therapy gedatolisib plus palbociclib and fulvestrant.
Sensei Biotherapeutics dosed the first patient in a Phase 1b/2 trial of PIKTOR (sapanisertib + serabelisib) in HR+/HER2- advanced breast cancer. The multi-node PI3K/AKT/mTOR inhibitor previously showed a 47% overall response rate in a Phase 1b trial.
Topline phase 3 VIKTORIA-1 results showed gedatolisib combinations improved progression-free survival versus alpelisib plus fulvestrant in PIK3CA-mutant HR-positive/HER2-negative advanced breast cancer. Celcuity plans a supplemental FDA filing based on the data.
FDA has accepted the NDA for vepdegestrant (ARV-471), an oral PROTAC ER degrader from Arvinas and Pfizer, for ESR1-mutated ER+/HER2- advanced breast cancer. A PDUFA date of June 5, 2026 has been set. The submission is based on positive Phase 3 VERITAC-2 data.
The SONIA trial found no overall survival benefit for first-line CDK4/6 inhibitors versus second-line use in advanced HR+/HER2- breast cancer. Median survival was 47.9 vs 48.1 months, though post hoc analysis suggested benefit in premenopausal patients. First-line treatment was associated with more severe adverse events.
Multiple phase 3 breast cancer trials reported significant findings in early 2026, including positive results for novel therapies across different subtypes. Key data includes progression-free survival benefits for palbociclib in HR-positive, HER2-positive advanced breast cancer and investigations of antibody-drug conjugates and combination therapies. Full trial findings are expected to be presented at upcoming medical meetings.
Novartis will acquire Pikavation Therapeutics for up to $3 billion to gain its PI3Kα inhibitor programs, led by SNV4818 for metastatic breast cancer. The deal includes $2 billion upfront and up to $1 billion in milestones, with completion expected in first half 2026. SNV4818 is designed to selectively target mutated PI3Kα while sparing healthy cells.
Recent developments in breast cancer treatment include new clinical trials for advanced disease, findings on CDK4/6 inhibitor sequencing, and discovery of genetic markers explaining drug resistance in HER2-positive breast cancer.
Proteolysis-targeting chimeras (PROTACs) are advancing from experimental to clinical-stage cancer therapies, with first candidates entering Phase III trials. The technology degrades target proteins rather than blocking them, offering new options for previously undruggable targets.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT07748208 |
A Study Evaluating the Safety of Inavolisib and Fulvestrant With or Without Palbociclib in Participants With Advanced Breast Cancer (ABC) and Type 2 Diabetes |
NOT_YET_RECRUITING | PHASE2 |
| NCT07716046 |
Fulvestaciclib Combined With Anti-HER2 and Endocrine Therapy for HR+/HER2+ Advanced Breast Cancer |
NOT_YET_RECRUITING | PHASE2 |
| NCT07679269 |
Roll-Over Study of Alpelisib (BYL719) for Continued Access and Long-Term Safety. |
NOT_YET_RECRUITING | PHASE2 |
| NCT07666555 |
A Phase II Clinical Study of the Efficacy and Safety of Culmerciclib Rechallenge in HR-positive, HER2-negative Breast Cancer Patients With Resistance to First-line Endocrine Therapy. |
RECRUITING | PHASE2 |
| NCT07619066 |
A Phase II Study of Zongertinib Plus Fulvestrant in Participants With HR-positive/HER2-negative Advanced Breast Cancer Harboring HER2 Mutations. |
NOT_YET_RECRUITING | PHASE2 |
| NCT07604571 |
Study of IEV407 as Single Agent or in Combination in Patients With Advanced HR+/HER2- Breast Cancer |
RECRUITING | PHASE1 |
| NCT07604272 |
Reversing InGuinal Hernia Trial: The Evaluation of Sex Hormones to Reverse Inguinal Hernias in Males |
RECRUITING | PHASE1 |
| NCT07570966 |
Study of ERW316 as a Single Agent or in Combination With Endocrine Therapy in Patients With HR+/HER2- Breast Cancer and Other Advanced Solid Tumors |
WITHDRAWN | PHASE1/PHASE2 |
| NCT07558733 |
Sapanisertib and Serabelisib (PIKTOR) in Various Combinations in Patients With HR+/HER2- Advanced/Metastatic Breast Cancer |
RECRUITING | PHASE1/PHASE2 |
| NCT07480681 |
Phase I Clinical Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of HLX97 (a KAT6A/B Inhibitor) in Patients With Advanced/Metastatic Solid Tumor |
NOT_YET_RECRUITING | PHASE1 |
