Drug Update · Oncology

Camizestrant at FDA ODAC April 30, 2026: SERENA-6 Showed PFS 16.0 vs 9.2 Months (HR 0.44)

August 13, 2026

NDA discussed at ODAC

NDA 220359 (AstraZeneca) discussed April 30, 2026 [2][3]

Primary endpoint (SERENA-6)

Investigator-assessed progression-free survival [5]

Median PFS

16.0 months (camizestrant) vs 9.2 months (aromatase inhibitor) [5]

Hazard ratio

HR 0.44; 95% CI, 0.31-0.60 [5]

Patients randomized

315 eligible patients randomized (157 camizestrant, 158 aromatase inhibitor) [5]

Clinical Perspective

This development affects oncologists and breast cancer specialists managing adults with HR-positive, HER2-negative locally advanced or metastatic breast cancer who detect ESR1 mutations during first-line endocrine-based therapy, per the ODAC meeting description ^[2]. The ODAC discussion and the SERENA-6 data support consideration of whether switching to camizestrant plus a CDK4/6 inhibitor at molecular detection of ESR1 mutation yields earlier PFS benefit, as reflected by median PFS 16.0 versus 9.2 months and HR 0.44 reported in SERENA-6 ^[4]. Will early switching at ESR1-mutation detection translate into improved long-term overall survival compared with continuing an aromatase inhibitor until radiographic progression?

Dr. Rahul Verma, MBBS, MD (General Medicine), DM (Medical Oncology) · Oncology

The FDA convened the Oncologic Drugs Advisory Committee (ODAC) on April 30, 2026 to discuss NDA 220359 for camizestrant tablets, submitted by AstraZeneca, for use in combination with a CDK4/6 inhibitor for adult patients with hormone receptor (HR)-positive, HER2-negative, locally advanced or metastatic breast cancer upon emergence of an ESR1 mutation during first-line endocrine-based therapy ^[2]. The SERENA-6 trial, cited in the briefing materials, reported investigator-assessed median progression-free survival of 16.0 months with camizestrant versus 9.2 months with an aromatase inhibitor (HR 0.44; 95% CI, 0.31 to 0.60) at a median follow-up of 12.6 months ^[4]^[3].

Clinical Context

Camizestrant is described in the ODAC materials as an oral estrogen receptor antagonist under review by the FDA; the applicant is AstraZeneca UK Limited / AstraZeneca Pharmaceuticals LP as noted in the FDA meeting announcement and briefing package ^[2]^[3]. The proposed indication discussed at ODAC is camizestrant in combination with a CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib) for treatment of adult patients with HR-positive, HER2-negative, locally advanced or metastatic breast cancer upon emergence of ESR1 mutation during first-line endocrine-based therapy, based on an FDA-authorized test ^[2]. FDA materials note that ESR1 mutations are an acquired resistance mechanism to aromatase inhibitors and that several oral estrogen receptor antagonists are already FDA approved for patients with tumor ESR1 mutations after progression on aromatase inhibitor and CDK4/6 inhibitor, while the benefit of switching earlier at detection of ESR1 mutation remains unknown ^[1]. The ODAC meeting materials framed the regulatory question around whether earlier switching at molecular detection of ESR1 mutation provides durable clinical benefit ^[1]^[3].

Key Findings

The SERENA-6 trial showed that camizestrant reduced the risk of progression or death versus an aromatase inhibitor (HR 0.44; 95% CI, 0.31-0.60). Median investigator-assessed progression-free survival was 16.0 months in the camizestrant group and 9.2 months in the aromatase-inhibitor group at an interim analysis with a median follow-up of 12.6 months ^[4].
Trial testing and enrollment figures in the published report: 3,256 patients were tested for an ESR1 mutation; 315 eligible patients were randomized, with 157 assigned to switch to camizestrant and 158 to continue an aromatase inhibitor ^[4].
Patient-reported global health status deterioration occurred later with camizestrant (median 21.0 months) than with an aromatase inhibitor (median 6.4 months; HR 0.54; 95% CI, 0.34 to 0.84) in SERENA-6 at the reported interim analysis ^[4].

These efficacy findings from SERENA-6 were a central part of the materials reviewed at the April 30, 2026 ODAC meeting for NDA 220359 ^[2]^[3]^[4].

Safety & Tolerability

A patient in SERENA-1 who received camizestrant with ribociclib experienced Torsades de Pointes requiring defibrillation, as noted in the FDA presentation materials ^[1].
The frequency of discontinuation because of adverse events in SERENA-6 was reported as 1.3% with camizestrant and 1.9% with an aromatase inhibitor in the published report ^[4].

Study Design

SERENA-6 was a randomized study in which patients with emerging ESR1 mutations detected during first-line endocrine-based therapy were assigned in a 1:1 ratio to switch to camizestrant (with continued CDK4/6 inhibitor and placebo in place of an aromatase inhibitor) or to continue an aromatase inhibitor plus a CDK4/6 inhibitor (with placebo in place of camizestrant); the primary endpoint was investigator-assessed progression-free survival ^[4]. The published report states that 3,256 patients were tested for ESR1 mutation and that 315 eligible patients were randomized (157 to camizestrant, 158 to aromatase inhibitor) with a median follow-up of 12.6 months at the interim analysis ^[4]. Regulatory context: the FDA ODAC convened on April 30, 2026 to discuss NDA 220359 for camizestrant, submitted by AstraZeneca, for the proposed ESR1-mutation emergence indication in combination with a CDK4/6 inhibitor ^[2]^[3].

FAQ

Q1 What is camizestrant currently being considered for?

Camizestrant is the subject of NDA 220359 submitted by AstraZeneca and was discussed at the FDA Oncologic Drugs Advisory Committee on April 30, 2026 for use in combination with a CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) for adult patients with hormone receptor (HR)-positive, HER2-negative, locally advanced or metastatic breast cancer upon emergence of an ESR1 mutation during first-line endocrine-based therapy, based on an FDA-authorized test. The FDA meeting materials describe this as the proposed indication under review. Q2 How does camizestrant work?

Camizestrant is described in the FDA materials as an oral estrogen receptor antagonist. The ODAC briefing documents and meeting announcement frame camizestrant’s development in the context of targeting tumors with ESR1 mutations that are associated with acquired resistance to aromatase inhibitors; further mechanistic and pharmacology details were not provided in the source excerpts. Q3 What dose was used in the reported trial?

In the SERENA-6 report cited in the meeting materials and the published trial, patients assigned to switch were given camizestrant and continued a CDK4/6 inhibitor; the published article describes the randomized comparison and reports outcomes but full dosing details beyond the trial assignment descriptions in the provided excerpts were limited in the source summary. Dosing information was not available in the provided source excerpts. Q4 What are the side effects reported?

The provided source excerpts report that in SERENA-6 the frequency of discontinuation because of adverse events was 1.3% with camizestrant and 1.9% with an aromatase inhibitor, and the FDA presentation materials note a patient in SERENA-1 who received camizestrant with ribociclib experienced Torsades de Pointes requiring defibrillation. Additional detailed adverse-event profiles and rates were not available in the provided source excerpts.

Clinicians should consult current prescribing information for complete dosing guidance.

Camizestrant at FDA ODAC April 30, 2026: SERENA-6 Showed PFS 16.0 vs 9.2 Months (HR 0.44)

Direct Clinical Takeaway & Evidence Summary

Camizestrant at FDA ODAC April 30, 2026: SERENA-6 Showed PFS 16.0 vs 9.2 Months (HR 0.44)

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

Get weekly clinical updates for Oncology in your inbox.

Related Clinical Updates

FDA Approves Sonrotoclax for Relapsed or Refractory Mantle Cell Lymphoma: 52% ORR

FDA Approves relacorilant for Platinum-Resistant Ovarian Cancer; PFS HR 0.70 (ROSELLA)

FDA Approves vepdegestrant for ESR1‑Mutated ER+ HER2‑ Breast Cancer; PFS HR 0.58 in VERITAC‑2

Verified HCP Portal