Key points
- Pertuzumab (Perjeta) is a second antibody against HER2 that is always given with trastuzumab [1].
- It is used in HER2-positive breast cancer, both in disease that has spread and before or after surgery in high-risk patients [1].
- In a large study in disease that had spread, adding pertuzumab usually helped patients live more than a year longer [1, 2].
- The most common side effect is diarrhoea [1].
- Like trastuzumab, it can weaken the heart and harm an unborn baby; avoid pregnancy until 7 months after the last dose [1].
What is this drug and how does it work?
For physicians
Pertuzumab, brand name Perjeta, is a humanised monoclonal antibody and HER2 receptor antagonist [1]. It binds to the dimerisation domain of HER2 (subdomain II) and stops HER2 from pairing with other HER family receptors, including EGFR, HER3 and HER4 [1]. As a result, two main cell growth signalling pathways (MAP kinase and PI3K) are blocked, which can lead to growth arrest and programmed death of the cancer cell [1]. Pertuzumab also recruits immune cells to attack cancer cells (antibody-dependent cell-mediated cytotoxicity, or ADCC) [1].
In laboratory models of HER2-positive tumours, combining pertuzumab with trastuzumab (Herceptin) had a greater antitumour effect than either alone [1]. This is why pertuzumab is given with trastuzumab (intravenous or subcutaneous), and if trastuzumab is stopped, pertuzumab must also be stopped permanently [1].
Which cancers is it used for?
According to the FDA label, pertuzumab is approved for adults with HER2-positive breast cancer, and patients should be selected on the basis of a validated HER2 test (protein overexpression or HER2 gene amplification) on a tumour sample [1]. Approved uses may differ between countries, and not every patient with breast cancer is a candidate for this drug.
Your doctor may prescribe this drug for:
- HER2-positive breast cancer — that has spread (first line) [1, 2, 3]
- Early HER2-positive breast cancer — before surgery [1, 4]
- Early HER2-positive breast cancer — after surgery [1, 5]
- HER2-positive breast cancer — that has spread, with trastuzumab deruxtecan [6, 7]
Whether it suits you depends on the type and stage of your cancer and your test results. Details of each use are in the section for doctors.
For physicians
| Cancer | Conditions of use | Key evidence |
|---|---|---|
| HER2-positive breast cancer — metastatic (first line) | With trastuzumab and docetaxel, in adults who have not had anti-HER2 therapy or chemotherapy for metastatic disease [1] | CLEOPATRA [2, 3]: median progression-free survival 18.5 vs 12.4 months (HR 0.62) and median overall survival 56.5 vs 40.8 months (HR 0.68) [1] |
| Early HER2-positive breast cancer — before surgery (neoadjuvant) | With trastuzumab and chemotherapy in locally advanced, inflammatory or early disease (tumour larger than 2 cm or node-positive), as part of a complete treatment plan [1] | NeoSphere [4]: pathological complete response 39.3% with pertuzumab + trastuzumab + docetaxel vs 21.5% with trastuzumab + docetaxel [1] |
| Early HER2-positive breast cancer — after surgery (adjuvant) | With trastuzumab and chemotherapy, in patients at high risk of recurrence [1] | APHINITY [5]: HR for invasive disease-free survival 0.82; in the node-positive subgroup HR 0.77 [1] |
| HER2-positive breast cancer — metastatic, with trastuzumab deruxtecan | Pertuzumab with trastuzumab deruxtecan as first-line treatment; this combination is approved in the Enhertu label [6] | DESTINY-Breast09 [7]: median progression-free survival 40.7 vs 26.9 months compared with THP (HR 0.56) [6] |
THP: taxane + trastuzumab + pertuzumab. The main source for the table is the FDA label.
How it is given and dose
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Treatment regimens and doses: index6 regimens
Pertuzumab is given as an intravenous infusion (drip) at the treatment centre once every 3 weeks and must not be given as a rapid intravenous injection [1]. The first dose is given over 60 minutes and later doses over 30 to 60 minutes [1]. Pertuzumab and trastuzumab can be given in either order, and the chemotherapy drug (a taxane) is given after them; you will be observed for 60 minutes after the first pertuzumab infusion and for 30 minutes after later infusions [1].
- Length of treatment: in early breast cancer, 1 year in total (up to 18 cycles), including the cycles before and after surgery [1]. In the CLEOPATRA study (metastatic disease), treatment continued until the disease progressed or side effects became unacceptable [1].
- Before starting: a HER2 test on a tumour sample, a measurement of heart function (left ventricular ejection fraction, or LVEF) and, in women who could become pregnant, a check of pregnancy status [1].
- During treatment: regular LVEF measurements (in the label: about every 12 weeks) [1].
- Before starting: HER2-positive by an approved test; baseline LVEF (early disease: 55% or more; after an anthracycline at least 50% before starting pertuzumab and trastuzumab; metastatic: 50% or more); pregnancy test [1].
- Administration: pertuzumab and trastuzumab in either order, then the taxane; observe for 30 to 60 minutes after each pertuzumab infusion before the next drug. Infusion reaction: slow or interrupt the infusion; serious hypersensitivity reaction: stop immediately. If trastuzumab is stopped, stop pertuzumab too [1].
- Missed dose: less than 6 weeks between two doses: pertuzumab 420 mg (and trastuzumab 6 mg/kg) as soon as possible; 6 weeks or more: re-load with 840 mg over 60 minutes (and trastuzumab 8 mg/kg), then the maintenance dose every 3 weeks [1].
- Adjustment by LVEF (pertuzumab dose reduction is not recommended) [1]:
- Metastatic: withhold pertuzumab and trastuzumab for at least 3 weeks if LVEF is below 40%, or 40 to 45% with a fall of 10 percentage points or more from baseline; resume after 3 weeks if LVEF rises above 45%, or 40 to 45% with a fall of less than 10 points.
- Early: withhold if LVEF is below 50% with a fall of 10 percentage points or more; resume after 3 weeks if LVEF is 50% or more, or the fall from baseline is less than 10 points.
- Monitoring: LVEF about every 12 weeks (in early disease at least once during the neoadjuvant period); signs of heart failure [1].
For physicians
Standard doses: with trastuzumab and chemotherapy (FDA label)
THP — pertuzumab + trastuzumab + docetaxel (CLEOPATRA)
HER2-positive metastatic breast cancer, first line (no previous anti-HER2 therapy or chemotherapy for metastatic disease)Cycle length: Every 3 weeks
HER2-positive metastatic breast cancer, first line (no previous anti-HER2 therapy or chemotherapy for metastatic disease)
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Pertuzumab | Initial dose 840 mg, then 420 mg | IV infusion; initial 60 minutes, then 30 to 60 minutes | Day 1 every 3 weeks |
| Trastuzumab | Initial dose 8 mg/kg, then 6 mg/kg (or subcutaneous 600 mg fixed dose) | IV; initial 90 minutes, then 30 to 90 minutes | Day 1 every 3 weeks |
| Docetaxel | 75 mg/m² (up to 100 mg/m² if tolerated) | IV, after pertuzumab and trastuzumab | Day 1 every 3 weeks |
[1]
Evidence: CLEOPATRA (2015), CLEOPATRA (2012)
Before surgery (neoadjuvant)
HER2-positive locally advanced, inflammatory or early breast cancer (more than 2 cm or node-positive)Cycle length: Every 3 weeks
HER2-positive locally advanced, inflammatory or early breast cancer (more than 2 cm or node-positive)
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Pertuzumab | Initial dose 840 mg, then 420 mg | IV infusion; initial 60 minutes, then 30 to 60 minutes | Day 1 every 3 weeks |
| Trastuzumab | Initial dose 8 mg/kg, then 6 mg/kg (or subcutaneous 600 mg fixed dose) | IV; initial 90 minutes, then 30 to 90 minutes | Day 1 every 3 weeks |
| One of the label regimens | |||
| Accompanying chemotherapy | 4 cycles of docetaxel, then 3 cycles of FEC after surgery; or 3 to 4 cycles of FEC, then 3 to 4 cycles of docetaxel; or 6 cycles of docetaxel + carboplatin (TCH; do not escalate docetaxel above 75 mg/m²); or 4 cycles of ddAC, then 4 cycles of paclitaxel | IV | — |
Pertuzumab and trastuzumab are given after the anthracycline is completed [1].
After surgery (adjuvant; APHINITY)
Early HER2-positive breast cancer at high risk of recurrenceCycle length: Every 3 weeks
Early HER2-positive breast cancer at high risk of recurrence
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Pertuzumab | Initial dose 840 mg, then 420 mg | IV infusion; initial 60 minutes, then 30 to 60 minutes | Day 1 every 3 weeks |
| Trastuzumab | Initial dose 8 mg/kg, then 6 mg/kg (or subcutaneous 600 mg fixed dose) | IV; initial 90 minutes, then 30 to 90 minutes | Day 1 every 3 weeks |
| Standard anthracycline- and/or taxane-containing chemotherapy | As per regimen | IV | — |
[1]
Evidence: APHINITY (2017)
Combined subcutaneous form (Phesgo)
All the uses above, instead of IV pertuzumab and trastuzumabCycle length: Every 3 weeks
All the uses above, instead of IV pertuzumab and trastuzumab
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Initial dose | |||
| Pertuzumab + trastuzumab + hyaluronidase | 1200 / 600 mg / 30,000 units (15 mL) | Subcutaneous in the thigh over about 8 minutes | Day 1 |
| Maintenance | |||
| Pertuzumab + trastuzumab + hyaluronidase | 600 / 600 mg / 20,000 units (10 mL) | Subcutaneous in the thigh over about 5 minutes | Every 3 weeks |
No weight-based adjustment. Observe for at least 30 minutes after the initial dose and 15 minutes after each maintenance dose. Switching from the IV form: if less than 6 weeks since the last dose, give the maintenance dose; 6 weeks or more, give the initial dose [8].
Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.
With trastuzumab deruxtecan (Enhertu label)
Trastuzumab deruxtecan + pertuzumab (DESTINY-Breast09)
HER2-positive metastatic or unresectable breast cancer, first lineCycle length: Every 3 weeks
HER2-positive metastatic or unresectable breast cancer, first line
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Trastuzumab deruxtecan | 5.4 mg/kg | IV infusion; initial 90 minutes, then 30 minutes | Day 1 |
| Pertuzumab | Cycle 1: 840 mg; then 420 mg | IV, 30 minutes after trastuzumab deruxtecan | Day 1 |
As in the Enhertu label; pertuzumab must not be given alone [6].
Evidence: DESTINY-Breast09 (2026)
Trastuzumab deruxtecan then THP (DESTINY-Breast11)
Early HER2-positive breast cancer, before surgeryCycle length: Every 3 weeks
Early HER2-positive breast cancer, before surgery
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| First 4 cycles | |||
| Trastuzumab deruxtecan | 5.4 mg/kg | IV | Every 3 weeks |
| Next 4 cycles | |||
| Taxane + trastuzumab + pertuzumab | Trastuzumab 6 mg/kg; pertuzumab 840 then 420 mg | IV | Every 3 weeks |
As in the Enhertu label [6].
Before prescribing, check each dose against the drug label, laboratory tests and the patient’s condition.
Side effects
The most common side effects:
- Diarrhoea is the most common side effect; once chemotherapy ends and only the two antibodies continue, it becomes much less common [1].
- Hair loss, nausea, tiredness and numbness in the hands and feet, mostly due to the accompanying chemotherapy [1].
- Skin rash, mouth sores and low white blood cells [1].
For physicians
In the CLEOPATRA trial (metastatic breast cancer), the most common side effects (more than 30%) with pertuzumab plus trastuzumab and docetaxel were: diarrhoea, hair loss, low neutrophils (a type of white blood cell), nausea, fatigue, skin rash and peripheral neuropathy (numbness or tingling in the hands and feet) [1].
As adjuvant treatment (APHINITY trial), the most common side effects (more than 30%) were diarrhoea, nausea, hair loss, fatigue, peripheral neuropathy and vomiting, and diarrhoea occurred in 71% of the pertuzumab group vs 45% of the placebo group [1]. After chemotherapy ended, when only pertuzumab and trastuzumab continued, diarrhoea was reported in 18% of patients [1].
The table below shows the frequency of common side effects in CLEOPATRA [1].
Serious side effects
These side effects are less common but serious; if you notice any sign of them, tell your team early:
- A weakened heart: shortness of breath, swollen legs or palpitations; this is why a heart scan (echocardiogram) is done before and during treatment [1].
- Harm to an unborn baby: do not become pregnant during treatment and for 7 months afterwards [1].
- A reaction during the infusion or a severe allergic reaction: chills, fever, shortness of breath or swelling [1].
- Fever with low white blood cells during chemotherapy [1].
For physicians
Boxed warning: the FDA label warns about two serious risks: left ventricular dysfunction and embryo-fetal toxicity [1].
- Cardiac dysfunction: in CLEOPATRA, left ventricular dysfunction occurred in 4% and symptomatic heart failure in 1% of patients in the pertuzumab group [1]. In APHINITY, symptomatic heart failure (class III or IV) with a fall in LVEF was seen in 0.6% of patients [1]. Patients who have previously had an anthracycline or chest radiotherapy may be at higher risk [1].
- Embryo-fetal toxicity: in animal studies pertuzumab caused fetal death and delayed kidney development, and use of a similar drug (trastuzumab) in pregnancy has been associated with oligohydramnios, pulmonary hypoplasia, skeletal abnormalities and neonatal death [1].
- Infusion reactions: these can be serious and even fatal [1]. In CLEOPATRA, on the first day when only pertuzumab was given, infusion reactions occurred in 13% of patients, fewer than 1% of them grade 3 or 4; in APHINITY the figure was 21% [1].
- Hypersensitivity and anaphylaxis: in CLEOPATRA, hypersensitivity reactions or anaphylaxis occurred in 11% of patients in the pertuzumab group, 2% grade 3 or 4 [1]. Pertuzumab is contraindicated in people with known hypersensitivity to it or its components [1].
- Febrile neutropenia: in CLEOPATRA it occurred in 14% of the pertuzumab group vs 8% of the placebo group; in Asian patients the rates were 26% vs 12% [1].
When should I call my doctor?
If you have any of the following symptoms, contact your doctor or treatment team straight away [1]:
- New or worsening shortness of breath, or a cough
- Swelling of the ankles or legs, or of the face
- Palpitations
- Weight gain of more than 5 pounds (about 2.3 kg) in 24 hours
- Dizziness or loss of consciousness
- Signs of a severe allergic reaction: swelling of the face, lips or tongue, difficulty breathing or chest pain
- Pregnancy or a possible pregnancy
In severe cases, such as severe shortness of breath, throat swelling or loss of consciousness, call your local emergency number.
Interactions, pregnancy and precautions
- Drug interactions: no important drug interactions are known for pertuzumab [1]. Give your treatment team a list of all your medicines and supplements.
- Pregnancy and contraception: pregnancy status is checked before starting, and women who could become pregnant should use effective contraception during treatment and for 7 months after the last dose of pertuzumab with trastuzumab [1]. If you become pregnant during this time, tell your doctor straight away [1].
- Breastfeeding: there is no information on whether pertuzumab passes into human milk; the decision about breastfeeding should be made with your doctor, taking into account the half-life of pertuzumab and the 7-month washout period of trastuzumab [1].
- Fertility: no specific fertility study has been done; in toxicity studies of up to 6 months in monkeys, no harmful effect on the reproductive organs was seen [1].
- Vaccines: the FDA label gives no specific advice about vaccination; talk to your treatment team before any vaccine.
- Missed appointment: contact the treatment centre as soon as possible rather than waiting for the next appointment; if 6 weeks or more have passed since the previous dose, a loading dose is given again [1].
- Kidneys: no dose adjustment is needed with mild or moderate kidney impairment [1].
Frequently asked questions
Is pertuzumab ever given on its own?
No. Pertuzumab is always given with trastuzumab (and in most regimens with chemotherapy), and if trastuzumab is stopped, pertuzumab is stopped too [1]. When combined with trastuzumab deruxtecan, pertuzumab must also not be given as a single agent [6].
How is pertuzumab different from trastuzumab?
How long does treatment last?
Does pertuzumab cause hair loss?
Scientific evidence
Show detailsHide
Key studies
1 itemTrastuzumab Deruxtecan plus Pertuzumab for HER2-Positive Metastatic Breast Cancer
Related cancer types
Treatment regimens (physicians)
References
8 referencesShow all references, 5 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1PERJETA (pertuzumab) injection, for intravenous use: Prescribing Information
- 2
- 3Pertuzumab plus Trastuzumab plus Docetaxel for Metastatic Breast Cancer
- 4Efficacy and safety of neoadjuvant pertuzumab and trastuzumab in women with locally advanced, inflammatory, or early HER2-positive breast cancer (NeoSphere): a randomised multicentre, open-label, phase 2 trial
- 5Adjuvant Pertuzumab and Trastuzumab in Early HER2-Positive Breast Cancer
- 6
- 7Trastuzumab Deruxtecan plus Pertuzumab for HER2-Positive Metastatic Breast Cancer
- 8PHESGO (pertuzumab, trastuzumab, and hyaluronidase-zzxf) injection, for subcutaneous use: Prescribing Information
This page is based on reputable scientific sources and was last updated on 27 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
Printed from the website; the full and up-to-date version: https://drdabiri.com/en/drugs/pertuzumab/