PI3K Inhibitor (Specialist Oncology Drug)

Alpelisib

Brand names: Piqray

Adult dose

Dose: Refer to BNF, SmPC, and current SACT protocol

Route: Oral

Frequency: As per SACT/MDT guidance

Clinical pearls

Indicated with fulvestrant for PIK3CA-mutated, HR+/HER2- advanced or metastatic breast cancer after endocrine therapy
SOLAR-1 trial demonstrated PFS benefit in PIK3CA-mutated tumours
NICE TA890 (2023): recommended for PIK3CA-mutated HR+/HER2- advanced breast cancer
PIK3CA mutation testing (tumour or ctDNA) required before prescribing
Hyperglycaemia management is critical — metformin, dietary advice, insulin as needed
Severe skin reactions (SJS/TEN) reported — monitor closely; withhold or discontinue

Contraindications

See SmPC — severe hypersensitivity
Severe hepatic impairment
See BNF for full list

Side effects

Hyperglycaemia (very common — class effect of PI3K inhibition)
Diarrhoea
Nausea
Rash (including severe cutaneous reactions)
Fatigue
Decreased appetite
Stomatitis
Pneumonitis

Interactions

CYP3A4 inducers — avoid (reduce alpelisib exposure)
CYP2C9 substrates — alpelisib is a CYP2C9 inhibitor; adjust doses of warfarin etc.
Refer to SmPC for full interaction profile

Monitoring

Fasting blood glucose / HbA1c before and during treatment
Skin (rash severity — use CTCAE grading)
LFTs
CT imaging per SACT protocol
Full blood count

Reference: BNF; NICE TA890 (Alpelisib with fulvestrant for PIK3CA-mutated HR+/HER2- advanced breast cancer, 2023); SOLAR-1 trial (NEJM 2019); ESMO Breast Cancer Guidelines; https://bnf.nice.org.uk/drugs/alpelisib/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways