Relay Therapeutics Announces Zovegalisib Granted Breakthrough Therapy Designation by U.S. FDA for PIK3CA-mutant, HR+/HER2- Advanced Breast Cancer
Rhea-AI Summary
Relay Therapeutics (Nasdaq: RLAY) announced the U.S. FDA granted Breakthrough Therapy designation to zovegalisib (RLY-2608) plus fulvestrant for adults with PIK3CA-mutant, HR+/HER2- locally advanced or metastatic breast cancer after progression on a CDK4/6 inhibitor.
BTD was supported by Phase 1/2 ReDiscover data including two comparable-dose cohorts: 600mg BID fasted (N=52) and 400mg BID fed (N=57), with 400mg BID as the Phase 3 dose; 400mg fed data will be presented March 16, 2026.
Positive
- FDA granted Breakthrough Therapy designation for zovegalisib plus fulvestrant
- Phase 1/2 ReDiscover included 600mg BID (N=52) and 400mg BID (N=57) cohorts
- 400mg BID fed chosen as the Phase 3 dose (ReDiscover-2)
Negative
- Not an approval; BTD accelerates review but regulatory approval is still required
- Phase 3 efficacy data for the 400mg BID fed dose not yet public (to be presented March 16, 2026)
- Target population limited to patients with PIK3CA mutations (~40% of HR+/HER2-)
Market Reaction
Following this news, RLAY has gained 4.48%, reflecting a moderate positive market reaction. Our momentum scanner has triggered 12 alerts so far, indicating notable trading interest and price volatility. The stock is currently trading at $8.52. This price movement has added approximately $63M to the company's valuation.
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Key Figures
Market Reality Check
Peers on Argus
RLAY gained 6.4% while key biotech peers like NRIX, IMTX and VIR also showed positive moves, but momentum scanners did not flag a coordinated sector move, indicating a stock-specific reaction to this BTD news.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Dec 12 | Clinical efficacy data | Positive | +3.1% | Reported detailed PFS and ORR data for zovegalisib plus fulvestrant cohort. |
| Nov 06 | Earnings and updates | Positive | -0.3% | Strong cash runway, lower R&D and G&A, and trial progress reported. |
| Nov 03 | Investor conferences | Neutral | -2.8% | Planned participation in November healthcare investor conferences and webcasts. |
| Oct 30 | Earnings date notice | Neutral | -2.7% | Announcement of upcoming Q3 2025 financial results release date. |
| Aug 28 | Investor conferences | Neutral | -2.7% | Scheduled September 2025 fireside chats at major healthcare conferences. |
Clinical updates on zovegalisib have previously drawn modest positive reactions, while earnings and conference participation have seen flat-to-negative moves, suggesting investors respond most to direct efficacy and development catalysts.
Recent news flow has centered on zovegalisib and corporate execution. On Dec 12, 2025, a subset efficacy analysis from the ReDiscover program in breast cancer produced a positive 3.08% move, highlighting investor focus on clinical depth. Q3 2025 results on Nov 6, 2025 showed substantial cash of $596.4M and reduced R&D and G&A spending, but the stock dipped slightly. Multiple conference participation announcements in late 2025 were followed by small declines, underscoring that direct clinical milestones like today’s BTD stand out most.
Market Pulse Summary
This announcement grants U.S. FDA Breakthrough Therapy designation to zovegalisib plus fulvestrant for PIK3CA-mutant HR+/HER2- advanced breast cancer, supported by Phase 1/2 ReDiscover data across 600mg BID fasted and 400mg BID fed cohorts. It builds on prior efficacy updates presented at ASCO 2025 and SABCS 2025 and precedes new data at the March 16, 2026 ESMO congress. Investors may watch future ReDiscover-2 Phase 3 readouts and subsequent regulatory interactions to gauge how this designation translates into longer-term development outcomes.
Key Terms
breakthrough therapy designation regulatory
fast track designation regulatory
pharmacokinetics medical
pharmacodynamics medical
antitumor activity medical
pik3ca medical
hr+/her2- medical
AI-generated analysis. Not financial advice.
Designation supported by robust clinical data from ReDiscover trial with 600mg BID fasted and 400mg BID fed doses of zovegalisib in combination with fulvestrant
Initial Phase 1/2 data of zovegalisib + fulvestrant at the 400mg BID fed (Phase 3 dose) in CDK4/6-experienced patients to be presented at ESMO Targeted Anticancer Therapies Congress on March 16
CAMBRIDGE, Mass., Feb. 03, 2026 (GLOBE NEWSWIRE) -- Relay Therapeutics, Inc. (Nasdaq: RLAY), a clinical-stage, small molecule precision medicine company developing potentially life-changing therapies for patients living with cancer and genetic disease, today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy designation (BTD) to zovegalisib (RLY-2608) in combination with fulvestrant for the treatment of adults with PIK3CA mutant, hormone receptor positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) locally advanced or metastatic breast cancer following recurrence or progression on or after treatment with a CDK4/6 inhibitor.
“Approximately
The FDA’s BTD is designed to accelerate the development and review of therapies for serious conditions when early clinical evidence suggests the potential for substantial improvement over available treatments. BTD provides eligibility for all Fast Track designation features, along with enhanced FDA guidance on development and increased engagement with senior FDA leadership.
BTD for zovegalisib was supported by clinical data generated to date from the Phase 1/2 ReDiscover trial, designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary antitumor activity of zovegalisib in combination with fulvestrant, and in combination with fulvestrant and CDK inhibitors. Specifically, the application included data across all PIK3CA mutations (kinase and non-kinase) for two doses with comparable exposures: 600mg BID fasted (N=52) and 400mg BID fed (N=57), the dose being used in the ongoing Phase 3 trial, ReDiscover-2.
Safety and efficacy from the 600mg BID fasted data referenced above were presented at the American Society of Clinical Oncology (ASCO) 2025 Annual Meeting, with an additional efficacy subgroup analysis presented at the 2025 San Antonio Breast Cancer Symposium (SABCS).
Data for the 400mg BID fed (the Phase 3 dose) will be presented for the first time at ESMO Targeted Anticancer Congress 2026 on Monday, March 16.
About Zovegalisib
Zovegalisib is the lead program in Relay Therapeutics’ efforts to discover and develop mutant selective inhibitors of PI3Kα, the most frequently mutated kinase in all cancers and all vascular anomalies. Zovegalisib has the potential, if approved, to address a significant portion of the approximately 140,000 patients with HR+, HER2- breast cancer with a PI3Kα mutation per year in the United States and the estimated 170,000 patients with vascular anomalies driven by a PI3Kα mutation per year in the United States.
Traditionally, the development of PI3Kα inhibitors has focused on the active, or orthosteric, site. The therapeutic index of orthosteric inhibitors is limited by the lack of clinically meaningful selectivity for mutant versus wild-type (WT) PI3Kα and off-isoform activity. Toxicity related to inhibition of WT PI3Kα and other PI3K isoforms results in sub-optimal inhibition of mutant PI3Kα with reductions in dose intensity and frequent discontinuation. The Dynamo® platform enabled the discovery of zovegalisib, the first known allosteric, pan-mutant, and isoform-selective PI3Kα inhibitor, designed to overcome these limitations. Relay Therapeutics solved the full-length cryo-EM structure of PI3Kα, performed computational long time-scale molecular dynamic simulations to elucidate conformational differences between WT and mutant PI3Kα, and leveraged these insights to support the design of zovegalisib. Zovegalisib is currently being evaluated in multiple metastatic breast cancer studies and a first-in-human study designed to treat patients with PIK3CA (PI3Kα) mutation driven vascular anomalies. For more information on zovegalisib, please visit here.
About PIK3CA-mutated, HR+/HER2- Advanced Breast Cancer
Hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer is the most common subtype of breast cancer. Approximately
About Relay Therapeutics
Relay Therapeutics (Nasdaq: RLAY) is a clinical-stage, small molecule precision medicine company developing potentially life-changing therapies for patients living with cancer and genetic disease. Relay's Dynamo® platform integrates an array of leading-edge computational and experimental approaches designed to drug protein targets that have previously been intractable or inadequately addressed. The company’s lead clinical asset, zovegalisib, is the first pan-mutant selective PI3Kα inhibitor to enter clinical development and is currently in a Phase 3 clinical trial (ReDiscover-2) in HR+/HER2- metastatic breast cancer. Zovegalisib is also being investigated in a group of genetic disease indications called PI3Kα-driven vascular anomalies. Relay's pipeline also includes programs for NRAS-driven solid tumors and Fabry disease. For more information, please visit www.relaytx.com or follow us on LinkedIn.
Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements regarding Relay Therapeutics’ strategy, business plans and focus; the progress and timing of the clinical development of the programs across Relay Therapeutics’ portfolio; the expected therapeutic benefits and potential efficacy and tolerability of zovegalisib, both as a monotherapy and in combination with other agents, and its other programs; the clinical data for zovegalisib; the interactions with regulatory authorities and any related approvals; the potential benefits resulting from the FDA’s breakthrough therapy designation to zovegalisib; and the potential market opportunity for zovegalisib. The words “may,” “might,” “will,” “could,” “would,” “should,” “plan,” “anticipate,” “intend,” “believe,” “expect,” “estimate,” “seek,” “predict,” “future,” “project,” “potential,” “continue,” “target” and similar words or expressions, or the negative thereof, are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.
Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks associated with: the impact of global economic uncertainty, geopolitical instability and conflicts, or public health epidemics or outbreaks of an infectious disease on countries or regions in which Relay Therapeutics has operations or does business, as well as on the timing and anticipated results of its clinical trials, strategy, future operations and profitability; the delay or pause of any current or planned clinical trials or the development of Relay Therapeutics’ drug candidates; the risk that the preliminary or interim results of its preclinical or clinical trials may not be predictive of future or final results in connection with future clinical trials of its product candidates and that interim and early clinical data may change as more patient data become available and are subject to audit and verification procedures; Relay Therapeutics’ ability to successfully demonstrate the safety and efficacy of its drug candidates; the timing and outcome of its planned interactions with regulatory authorities; and obtaining, maintaining and protecting its intellectual property. These and other risks and uncertainties are described in greater detail in the section entitled “Risk Factors” in Relay Therapeutics’ most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q, as well as any subsequent filings with the Securities and Exchange Commission. In addition, any forward-looking statements represent Relay Therapeutics' views only as of today and should not be relied upon as representing its views as of any subsequent date. Relay Therapeutics explicitly disclaims any obligation to update any forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.
Contact:
Pete Rahmer
prahmer@relaytx.com
Media:
Dan Budwick
1AB
973-271-6085
dan@1abmedia.com
FAQ
What did Relay Therapeutics announce about zovegalisib (RLAY) on February 3, 2026?
What doses and patient cohorts supported the FDA Breakthrough Therapy designation for RLAY's zovegalisib?
What does Breakthrough Therapy designation mean for zovegalisib (RLAY) development timeline?
When will Relay present additional ReDiscover data for the 400mg BID fed dose of zovegalisib?
Which patient population is targeted by zovegalisib plus fulvestrant under the BTD for RLAY?
