Skuteczność i bezpieczeństwo alpelisibu z trastuzumabem i pertuzumabem w terapii podtrzymującej u dorosłych z przerzutowym rakiem piersi HER2‑pozytywnym i mutacją PIK3CA

Baseline Assessment

After enrollment you undergo a series of examinations that include medical history, physical Examination, blood tests, and imaging studies to document the extent of the disease.

A tissue or blood sample is tested for the presence of a PIK3CA mutation, which determines eligibility for the study.

Randomization

Based on the test results you are assigned by the study system to one of two groups: the active treatment Group receiving alpelisib together with trastuzumab and pertuzumab, or the control Group receiving a placebo together with trastuzumab and pertuzumab.

Start of part 1 safety run‑in

You begin taking alpelisib orally at a dose of 300 mg once daily.

Trastuzumab is administered by intravenous infusion at a dose of 6 mg per kilogram of body weight.

Pertuzumab is administered by intravenous infusion at a fixed dose of 420 mg.

The medication schedule follows the protocol‑defined treatment cycles, and you receive the infusions on the days specified by the study.

During the first 6 weeks the study team closely monitors you for any dose‑limiting toxicity, which are side effects that may require dose changes.

Safety evaluation after 6 weeks

After the initial 6‑week period the investigators review safety data to confirm that the 300 mg dose of alpelisib is tolerable when combined with the two infusions.

If the dose is confirmed you continue to the next phase of the study.

Part 2 double‑blind maintenance therapy

You continue receiving the assigned study medication for the remainder of the trial.

The active Group takes alpelisib 300 mg orally each day, while the control Group takes a matching placebo tablet.

Both groups receive trastuzumab 6 mg/kg and pertuzumab 420 mg by intravenous infusion at the regular interval defined by the protocol (typically every three weeks).

Treatment is continued until disease progression, unacceptable side effects, or the end of the study period.

Regular monitoring

At each visit you undergo physical Examination, blood tests, and Assessment of any adverse events.

Imaging studies are performed periodically to evaluate tumor size according to the RECIST 1.1 criteria, which determines progression‑free survival.

Dose adjustments

If side effects occur, the study protocol allows temporary interruption, reduction, or discontinuation of alpelisib or the infusions according to predefined rules.

End of treatment

Treatment stops when the investigators determine that the disease has progressed, side effects are no longer manageable, or the study reaches its planned end date.

After discontinuation you may continue routine follow‑up care as recommended by your physician.