FDA Flashback: Breast Cancer Decisions and News From April 2026

Catch a glimpse of the breast cancer–related FDA decisions granted in April 2026, including an Oncologic Drugs Advisory Committee (ODAC) update regarding camizestrant in hormone receptor–positive breast cancer, as well as a breakthrough device designation. Then, look ahead to anticipated approvals for this disease.

What was the ODAC decision regarding camizestrant switch in hormone receptor–positive breast cancer following ESR1 mutation detection?

On April 30, 2026, the FDA’s ODAC voted 6-3 against the clinical benefit of switching to camizestrant upon the emergence of an ESR1 mutation during treatment with an aromatase inhibitor and a CDK4/6 inhibitor before the progression of radiographic disease in patients with hormone receptor–positive, HER2-negative metastatic breast cancer.¹

The committee reviewed and discussed data from the phase 3 SERENA-6 trial (NCT04964934), which were included to support the new drug application (NDA) seeking the approval of camizestrant plus a CDK4/6 inhibitor (palbociclib [Ibrance], ribociclib [Kisqali], or abemaciclib [Verzenio]) for the treatment of adult patients with hormone receptor–positive, HER2-negative, locally advanced or metastatic breast cancer whose disease develops an emergent ESR1 mutation during first-line endocrine-based therapy, based on the results of an FDA-approved test. Findings from SERENA-6 presented at the 2025 ASCO Annual Meeting demonstrated that among patients who switched to camizestrant in combination with a CDK4/6 inhibitor (n = 157), the investigator-assessed median progression-free survival (PFS) was 16.0 months (95% CI, 12.7-18.2) compared with 9.2 months (95% CI, 7.2-9.5) with continued treatment using an aromatase inhibitor plus a CDK4/6 inhibitor with an aromatase inhibitor plus CDK4/6 inhibition (n = 158; HR, 0.44; 95% CI, 0.31-0.60; P < .00001).² Furthermore, updated data shared at the 2025 San Antonio Breast Cancer Symposium showed a median PFS of 16.6 months (95% CI, 14.7-19.4) in the camizestrant arm vs 9.2 months (95% CI, 7.2-9.7) in the control arm (HR, 0.46; 95% CI, 0.34-0.62; P < .00001).³

What FDA breakthrough device designation was granted in April 2026?

On April 29, 2026, the FDA granted breakthrough device designation to the AidaBREAST test for prognostic risk assessment and benefit prediction for the use of radiation therapy in patients with early-stage (stage I to IIa) invasive breast cancer.⁴ This assay uses multi-omic data to create a patient-specific report of 10-year locoregional recurrence risk, as well as predict benefit from radiation therapy following breast-conserving surgery.

What anticipated FDA approvals might alter the breast cancer treatment paradigm over the next couple months?

The FDA granted priority review to a supplemental biologics license application (sBLA) seeking the approval of the antibody-drug conjugate datopotamab deruxtecan-dlnk (Datroway) for the frontline treatment of adult patients with unresectable or metastatic triple-negative breast cancer who are not eligible for treatment with PD-1– or PD-L1–directed immunotherapy.⁵ The sBLA has a Prescription Drug User Fee Act (PDUFA) target action date in the second quarter of 2026.

The FDA is also reviewing an sBLA seeking the approval of neoadjuvant fam-trastuzumab deruxtecan-nxki (Enhertu) followed by paclitaxel, trastuzumab (Herceptin), and pertuzumab (Perjeta) for the treatment of adult patients with high-risk, HER2-positive, stage II/III breast cancer, with a PDUFA target action date of May 18, 2026.⁶

Additionally, the FDA is reviewing an NDA seeking the approval of vepdegestrant for the treatment of patients with estrogen receptor–positive/HER2-negative, ESR1-mutated advanced or metastatic breast cancer who have received prior endocrine-based therapy.⁷ This NDA has a PDUFA target action date of June 5, 2026.

References

1. April 30, 2026 meeting of the Oncologic Drugs Advisory Committee (ODAC). FDA. Accessed April 30, 2026. https://www.youtube.com/live/taCx7enN7hk
2. Turner N, Mayer E, Park YH, et al. Camizestrant + CDK4/6 inhibitor (CDK4/6i) for the treatment of emergent ESR1 mutations during first-line (1L) endocrine-based therapy (ET) and ahead of disease progression in patients (pts) with HR+/HER2– advanced breast cancer (ABC): phase 3, double-blind ctDNA-guided SERENA-6 trial. J Clin Oncol. 2025;43(suppl 17):LBA4. doi:10.1200/JCO.2025.43.17_suppl.LBA4
3. Bidard FC, Mayer EL, Park YH, et al. Updated results and an exploratory analysis of ESR1m circulating tumor DNA dynamics from SERENA-6, a phase 3 trial of camizestrant + CDK4/6 inhibitor for emergent ESR1m during first-line endocrine-based therapy and ahead of disease progression in patients with HR+/HER2– advanced breast cancer. Presented at: 2025 San Antonio Breast Cancer Symposium; December 9-12, 2025; San Antonio, TX. Abstract RF7-03.
4. PreludeDx receives FDA breakthrough device designation for AidaBREAST - early-stage invasive breast cancer assay. News release. PreludeDx. April 29, 2026. Accessed May 1, 2026. https://preludedx.com/wp-content/uploads/2026/04/PreludeDx-Receives-FDA-Breakthrough-Device-Designation-for-AidaBREAST%E2%84%A2-4_29_2026.pdf
5. Datroway (datopotamab deruxtecan-dlnk) granted priority review in the US as 1st-line treatment for patients with metastatic triple-negative breast cancer who are not candidates for immunotherapy. News release. AstraZeneca. February 3, 2026. Accessed May 1, 2026. https://www.astrazeneca-us.com/media/press-releases/2026/DATROWAY-datopotamab-deruxtecan-dlnk-granted-Priority-Review-in-the-US-as-1st-line-treatment-for-patients-with-metastatic-triple-negative-breast-cancer-who-are-not-candidates-for-immunotherapy.html
6. Enhertu followed by THP supplemental biologics license application accepted in the U.S. for patients with high-risk HER2 positive early-stage breast cancer prior to surgery. News release. Daiichi Sankyo. October 1, 2025. Accessed May 1, 2026. https://www.daiichisankyo.com/files/news/pressrelease/pdf/202510/20251001_E.pdf
7. Arvinas announces FDA acceptance of the new drug application for vepdegestrant for the treatment of ESR1m, ER+/HER2- advanced breast cancer. News release. Arvinas. August 8, 2025. Accessed May 1, 2026. https://ir.arvinas.com/news-releases/news-release-details/arvinas-announces-fda-acceptance-new-drug-application