> Trialight public data. Index of pages: https://trialight.com/llms.txt
> Web page: https://trialight.com/data/asset/stx-478-be747e6f-d1c8-48a7-a2d8-05107a77ab5f
> Record changed: 2026-10-13

# STX-478

Highest phase reached

Phase 1

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

Drug type

Small molecule

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

## Development status

**Listing at source**

Listed

**Highest phase reached**

Phase 1

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

## Names and chemistry

**Drug type**

Small molecule

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

**Drug name**

STX-478

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

**Molecular weight**

401.3

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

**Structure (SMILES)**

Cc1c(\[C@@H\](NC(=O)Nc2cnc(N)nc2)C(F)(F)F)oc2c(F)cc(F)cc12

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

### Other names (11)

- ly4064809
- LY4064809
- stx 478
- Stx-478
- STX-478
- tersolisib
- Tersolisib
- tersolisib \[INN\]
- TERSOLISIB \[USAN\]
- tersolisib inn
- tersolisib usan

## Identifiers

**CAS registry numbers**

- 2883540-92-7

**ChEMBL ID**

CHEMBL5421037

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

**InChIKey**

LGPNQALKGDDVBD-CYBMUJFWSA-N

Source: [www.ebi.ac.uk](https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL5421037)

**PubChem compound IDs**

- 166532451

**FDA ingredient codes (UNII)**

- AGX9NKC8M9

## Regulatory information

### Other regulatory facts

**First in class**

No

**Orphan designation**

No

## Pharmacology

### Drug classification

**Pharmacology name**

tersolisib

**Type**

Synthetic organic

### Mechanisms of action (3)

- **Action type**  
Inhibitor

**Target**  
phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha

**Gene symbol**  
phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha
- **Action**  
Inhibition

**Action type**  
Inhibitor

**Target**  
phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha

**Gene symbol**  
PIK3CA

**Protein identifier**  
P42336

**Median affinity**

7.15

**Affinity units**  
pKd
- **Action**  
Inhibition

**Action type**  
Inhibitor

**Target**  
phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha

**Gene symbol**  
PIK3CA

**Protein identifier**  
P42336

**Median affinity**

8.33

**Affinity units**  
pKd

### Open Targets indications

- **Condition identifier**  
MONDO\_0007254

**Highest recorded phase**  
1

## Chemical properties

**Hydrogen bond acceptors**

5

**Hydrogen bond donors**

3

**Polar surface area**

106.07

**Calculated partition coefficient (ALogP)**

3.82

**Calculated partition coefficient (XLogP)**

2.5

**Prodrug**

No

**Chirality**

Single enantiomer

**Inorganic**

No

**Rule-of-five violations**

0

**Rotatable bonds**

3

**Heavy atoms**

28

**Molecular formula**

C16H12F5N5O2

**Monoisotopic mass**

401.09111545

**Natural product**

No

## Evidence counts

**Recorded assays**

61

**Active assays**

3

### Active assay types

- Confirmatory

## Related records

### Trials (8)

- A Study of \[14C\]-LY4064809 in Healthy Participants
- A Study of Food Effect and Esomeprazole on LY4064809 in Healthy Adult Participants
- A Study of Food Effect on Tersolisib (LY4064809) in Healthy Participants
- A Study of LY4064809 \[14C\]-STX-478 in Healthy Male Participants
- A Study of LY4064809 in Healthy Adult Chinese Participants
- A Study of LY4064809 in Healthy Adult Participants
- A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA)
- [First-in-Human Study of Tersolisib (STX-478) as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors](https://trialight.com/data/trial/first-in-human-study-of-tersolisib-stx-478-as-monotherapy-281c6acd-8b34-4767-a985-3022d47a201c.md)

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