---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-23-013199"
form_type: "8-K"
ticker: "RLAY"
cik: "0001812364"
company_name: "Relay Therapeutics, Inc."
filed_at: "2023-04-18T23:59:59+00:00"
generated_at: "2026-06-17T00:51:34.850351+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# RLY-2608 shows selective PI3Kα inhibition, no Grade 3 hyperglycemia, partial response in breast cancer

## Summary
- No Grade 3 hyperglycemia, rash, or diarrhea at target exposures; no dose-limiting toxicities or discontinuations.
- Confirmed partial response (RECIST) in metastatic HR+/HER2- breast cancer patient with 12 prior lines of therapy.
- Target exposure (~80%+ mutant PI3Kα inhibition) achieved at 400mg BID monotherapy and 600/800mg BID combination.
- Nine of 16 breast cancer patients with measurable disease had radiographic tumor reductions; 11 remain on treatment.
- Expansion cohorts expected in H2 2023; new first-in-human trial for second PI3Kα inhibitor RLY-5836 initiated April 2023.

## SEC filing metadata
- accession: 0000950170-23-013199
- form_type: 8-K
- ticker: RLAY
- cik: 0001812364
- company_name: Relay Therapeutics, Inc.
- filed_at: 2023-04-18T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1812364/000095017023013199/0000950170-23-013199-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1812364/000095017023013199/rlay-20230418.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-23-013199
- JSON: https://secwatch.observer/filing/0000950170-23-013199.json
- Plain text: https://secwatch.observer/filing/0000950170-23-013199.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.