Pharmacokinetic and exposure-response analyses of pertuzumab in combination with trastuzumab and docetaxel during neoadjuvant treatment of HER2+ early breast cancer

gPKPDviz: A flexible R shiny tool for pharmacokinetic/pharmacodynamic simulations using mrgsolve

GPKPDviz is a Shiny application (app) dedicated to real-time simulation, visualization, and assessment of the pharmacokinetic/pharmacodynamic (PK/PD) models. Within the app, gPKPDviz is capable of generating virtual populations and complex dosing and sampling scenarios, which, together with the streamlined workflow, is designed to efficiently assess the impact of covariates and dosing regimens on PK/PD end points. The actual population data from clinical trials can be loaded into the app for simulation if desired. The app-generated dosing regimens include single or multiple dosing, and more complex regimens, such as loading doses or intermittent dosing. When necessary, the dosing regimens can be defined externally and loaded to the app for simulation. Using mrgsolve as the simulation engine, gPKPDviz is typically used for population simulation, however, with a slight modification of the mrgsolve model, gPKPDviz is capable of performing individual simulations with individual post hoc parameters, individual dosing logs, and individual sampling timepoints through an external dataset. A built-in text editor has a debugging feature for the mrgsolve model, providing the same error messages as model compilation in R. GPKPDviz has had stringent validation by comparing simulation results between the app and using mrgsolve in R. GPKPDviz is a member of the suite of Modeling and Simulation Shiny apps developed at Genentech to facilitate the typical modeling work in Clinical Pharmacology. For broader access to the Pharmacometric community, gPKPDviz has been published as an open-source application in GitHub under the terms of GNU General Public License.

Generation and Characterization of Trastuzumab/Pertuzumab-Resistant HER2-Positive Breast Cancer Cell Lines

The combination of trastuzumab and pertuzumab as first-line therapy in patients with HER2-positive breast cancer has shown significant clinical benefits compared to trastuzumab alone. However, despite initial therapeutic success, most patients eventually progress, and tumors develop acquired resistance and invariably relapse. Therefore, there is an urgent need to improve our understanding of the mechanisms governing resistance in order to develop targeted therapeutic strategies with improved efficacy. We generated four novel HER2-positive cell lines via prolonged exposure to trastuzumab and pertuzumab and determined their resistance rates. Long-term resistance was confirmed by a significant increase in the colony-forming capacity of the derived cells. We authenticated the molecular identity of the new lines via both immunohistochemistry for the clinical phenotype and molecular profiling of point mutations. HER2 overexpression was confirmed in all resistant cell lines, and acquisition of resistance to trastuzumab and pertuzumab did not translate into differences in ER, PR, and HER2 receptor expression. In contrast, changes in the expression and activity of other HER family members, particularly HER4, were observed. In the same vein, analyses of the receptor and effector kinase status of different cellular pathways revealed that the MAPK pathway may be involved in the acquisition of resistance to trastuzumab and pertuzumab. Finally, proteomic analysis confirmed a significant change in the abundance patterns of more than 600 proteins with implications in key biological processes, such as ribosome formation, mitochondrial activity, and metabolism, which could be relevant mechanisms in the generation of resistance in HER2-positive breast cancer. We concluded that these resistant BCCLs may be a valuable tool to better understand the mechanisms of acquisition of resistance to trastuzumab and pertuzumab-based anti-HER2 therapy.

Alternative Trastuzumab Dosing Schedules Are Associated With Reductions in Health Care Greenhouse Gas Emissions

PURPOSE

Cancer care-related greenhouse gas (GHG) emissions harm human health. Many cancer drugs are administered at greater-than-necessary doses, frequencies, and durations. Alternative dosing strategies may enable reductions in cancer care GHG emissions without compromising patient outcomes.

MATERIALS AND METHODS

We used streamlined life-cycle analysis in a case-control simulation to estimate the relative reductions in GHG emissions that would be expected to result from using each of three alternative dosing strategies of trastuzumab (6-month adjuvant treatment duration, once every 4-week dosing, and both) in human epidermal growth factor receptor 2 (HER2)+ breast cancer. Using primary data and conversion factors from the environmental science literature, we estimated per-patient relative reduction in GHG emissions and, using SEER data, health impacts (in terms of disability-adjusted life-years [DALYs] and excess mortality per kg CO2) on bystanders for each alternative dosing strategy.

RESULTS

Compared with the trastuzumab dosing strategy commonly used at baseline (12-month duration of adjuvant therapy and once every 3-week dosing in all settings), adoption of both 6-month adjuvant trastuzumab and once every 4-week trastuzumab dosing would reduce GHG emissions by 4.5%, 18.7%, and 14.6% in the neoadjuvant, adjuvant, and metastatic settings, respectively. We estimate that US-based adoption of alternative trastuzumab dosing would reduce annual DALYs and excess lives lost due to environmental impact of US-based trastuzumab therapy for HER2+ breast cancer by 1.5 and 0.9, respectively.

CONCLUSION

Alternative dosing strategies may materially reduce the population health impacts of cancer care by reducing environmental impact. Regulatory decision making and health technology assessments should consider a treatment's environmental and population health impacts. Clinical trials of alternative dosing strategies are justified on the basis of environmental and population health impacts.

Neoadjuvant pertuzumab in non‑metastatic HER2‑positive breast tumors: Multicentric study in Peru (NeoHer)

Several clinical trials have demonstrated the benefit of adding pertuzumab to trastuzumab plus neoadjuvant chemotherapy in the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The comparison of outcomes between nonrandomized groups of patients who received similar treatments in routine practice remains difficult. The present study aimed to evaluate the pathological complete response (pCR) rates achieved with pertuzumab among patients in routine clinical care in Peru using real-world data. The definition of pCR used was the absence of residual invasive cancer from the complete resected breast specimen and all sampled regional lymph nodes following completion of neoadjuvant systemic therapy. A total of 44 patients with non-metastatic HER2-positive breast cancer (stages II and III) treated with pertuzumab in the neoadjuvant setting and who underwent surgery at three private clinics in Lima (Peru) were retrospectively evaluated. The pCR was the efficacy endpoint and it was determined and compared with the results from other clinical trials. Furthermore, safety data were described. The median age was 44 years (interquartile range, 39.5-50.5 years) and 65.9% of patients were premenopausal. Regarding the clinical stage, 56.8% were IIA/IIB and 36.4% were IIIA/IIIB/IIIC. All treatment schemes included concurrent trastuzumab. The patients' treatment comprised neoadjuvant therapy of docetaxel/trastuzumab/pertuzumab (THP) with a median of 4 cycles in 30 patients (68.2%) or docetaxel/trastuzumab/pertuzumab/carboplatin (THPCarb) with a median of 6 cycles in 14 patients (31.8%). In total, 70.5% of patients experienced pCR; among hormone receptor-negative cases, 75.0% achieved pCR and in tumors expressing hormone receptors, the rate of pCR was 66.7%. Of those patients subjected to neoadjuvant treatment with THP, 66.7% (20/30) achieved pCR, whereas 78.6% (11/14) of patients who received THPCarb had a pCR. The incidence of drug-related adverse events was 59.1% and in none of the patients, administration was discontinued due to toxicity. The present results of Peruvian patients with HER2 breast cancer treated according to clinical routine demonstrated that dual blockade of HER2 with trastuzumab and pertuzumab in the neoadjuvant setting achieved high rates of pCR even in hormone receptor-positive patients. These results are consistent with those of randomized controlled trials, with a good safety profile.

Individualized treatment of breast cancer with chronic renal failure: A case report and review of literature

BACKGROUND

Studies have shown that patients with chronic renal failure (CRF) are more likely to suffer from breast cancer and other malignant tumors. To our knowledge, CRF can reduce drug excretion, thereby increase drug exposure and lead to increased toxicity, which will limit drug treatment and lead to tumor progression. Currently, there are few successful reports on the combination of docetaxel, trastuzumab, and pertuzumab (THP) as a neoadjuvant treatment regimen for breast cancer patients with CRF.

CASE SUMMARY

We report a breast cancer (cT2N2M0, Her-2+/HR-) patient with CRF. It was a clinical stage IIIA tumor on the left breast. The patient had suffered from uremia for 2 years, and her heart function was normal. Based on the pathological type, molecular type, and clinical stage of breast cancer, and the patient’s renal function, the clinician analyzed the pharmacological and pharmacokinetic characteristics of the antitumor drugs after consulting the relevant literature, and prescribed the neoadjuvant regimen of THP (docetaxel 80 mg/m², trastuzumab 8 mg/kg for the first dose, and 6 mg/kg for the maintenance dose with pertuzumab 840 mg for the first dose and 420 mg for the maintenance dose), once every 3 wk, for a total of 6 courses. The neoadjuvant treatment had a good effect, and the patient then underwent surgery which was uneventful.

CONCLUSION

CRF is not a contraindication for systemic treatment and surgery of breast cancer. The THP regimen without dose adjustment may be a safe and effective neoadjuvant treatment for HER-2 positive breast cancer patients with CRF.

Impact of Dose Delays and Alternative Dosing Regimens on Pertuzumab Pharmacokinetics

PERJETA (pertuzumab), administered with Herceptin (trastuzumab), is used in the treatment of human epidermal growth factor receptor 2-positive breast cancer. Pertuzumab is currently approved with an initial loading dose of 840 mg, followed by a 420-mg maintenance dose intravenously every 3 weeks. A reloading dose is required if there is a ≥6-week delay in treatment. In response to the potential treatment disruption due to COVID-19, the impact of dose delays and alternative dosing regimens on intravenous pertuzumab for human epidermal growth factor receptor 2-positive breast cancer treatment is presented. Simulations were conducted by using the validated population pharmacokinetic model for pertuzumab, and included (1) 4-, 6-, and 9-week dose delays of the 840 mg/420 mg every 3 weeks dosing regimen and (2) 840 mg/420 mg every 4 weeks and 840 mg every 6 weeks alternative dosing regimens. Simulations were compared with the currently approved pertuzumab dosing regimen. The simulations in 1000 virtual patients showed that a dose reload (840 mg) is required following a dose delay of ≥6 weeks to maintain comparable Ctrough (lowest concentration before the next dose is given) levels to clinical trials. The 840 mg/420 mg every 4 weeks and 840 mg every 6 weeks alternative dosing regimens decrease median steady-state Ctrough by ≈40% compared with the approved regimen, and <90% of patients will be above the target Ctrough . Thus, the alternative 840 mg/420 mg every 4 weeks and 840 mg every 6 weeks pertuzumab dosing regimens are not recommended. Flexibility for intravenous PERJETA-based regimens is available with an alternative route of pertuzumab administration (subcutaneous vs intravenous).

Population pharmacokinetic and exploratory exposure-response analysis of the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection in patients with HER2-positive early breast cancer in the FeDeriCa study

Purpose

To characterize pertuzumab pharmacokinetics (PK) in FeDeriCa (NCT03493854: fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection [PH FDC SC] versus intravenous pertuzumab plus trastuzumab); derive individual pertuzumab exposures in the PH FDC SC arm for subsequent pertuzumab exposure–response (ER) analyses; compare observed trastuzumab PK with predicted exposures from a previous SC trastuzumab model; assess whether pertuzumab affects trastuzumab PK; evaluate pertuzumab exposure–efficacy and –safety relationships and support the approved SC dosing regimen.

Methods

Population pharmacokinetic modeling and simulations were used to describe the data. Standard goodness-of-fit diagnostics and prediction-corrected visual predictive checks were used for model performance assessment. Covariates were included from previously reported models. ER analysis was conducted using logistic regression.

Results

SC pertuzumab PK was described adequately by a two-compartment model with first-order absorption; significant covariates included in the final model were albumin, lean body weight, and Asian region; however, these appeared not to be clinically relevant. Trastuzumab concentrations were described adequately by the previous model; there was no evidence of a pertuzumab effect on trastuzumab PK as part of PH FDC SC and higher model-predicted pertuzumab exposure was not associated with differences in pathologic complete response rate or an increased probability of selected grade ≥ 3 adverse events of interest.

Conclusion

The approved PH FDC SC dose [loading: 1200/600 mg pertuzumab/trastuzumab (15 mL); maintenance: 600 mg pertuzumab/trastuzumab (10 mL) and 2000 U/mL recombinant human hyaluronidase every 3 weeks] provides a positive benefit–risk profile with comparable efficacy and safety to intravenous pertuzumab plus trastuzumab.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-021-04296-0.

Drug Exposure to Establish Pharmacokinetic-Response Relationships in Oncology

In the oncology field, understanding the relationship between the dose administered and the exerted effect is particularly important because of the narrow therapeutic index associated with anti-cancer drugs and the high interpatient variability. Therefore, in this review, we provide a critical perspective of the different methods of characterising treatment exposure in the oncology setting. The increasing number of modelling applications in oncology reflects the applicability and the impact of pharmacometrics on all phases of the drug development process and patient management as well. Pharmacometric modelling is a worthy component within the current paradigm of model-based drug development, but pharmacometric modelling techniques are also accessible for the clinician in the optimisation of current oncology therapies. Consequently, the application of population models in a hospital setting by generating close collaborations between physicians and pharmacometricians is highly recommended, providing a systematic means of developing and assessing model-based metrics as 'drivers' for various responses to treatments, which can then be evaluated as predictors for treatment success. Characterising the key determinants of variability in exposure is of particular importance for anticancer agents, as efficacy and toxicity are associated with exposure. We present the different strategies to describe and predict drug exposure that can be applied depending on the data available, with the objective of obtaining the most useful information in the patients' favour throughout the full drug cycle. Therefore, the objective of the present article is to review the different approaches used to characterise a patient's exposure to oncology drugs, which will result in a better understanding of the time course of the response and the magnitude of interpatient variability.

Pharmacokinetics of pertuzumab administered concurrently with trastuzumab in Chinese patients with HER2-positive early breast cancer

In the APHINITY study (NCT01358877, BIG 4-11/BO25126/TOC4939G), pertuzumab added to trastuzumab and chemotherapy significantly improved invasive disease-free survival as adjuvant treatment for patients with HER2-positive early breast cancer. The objective of this analysis was to assess the pharmacokinetics of pertuzumab in combination with trastuzumab in Chinese patients with early breast cancer. Samples for pertuzumab and trastuzumab pharmacokinetic analysis were taken from Chinese patients during cycle 1 of treatment and at steady-state in cycle 10. Noncompartmental analysis was used to estimate minimum and maximum serum concentrations (Cmax and Cmin), area under the concentration-time curve, clearance, and other pharmacokinetic parameters. In 15 patients, mean steady-state Cmax and Cmin pertuzumab serum concentrations (368 ± 177 μg/ml, and 122 ± 47 μg/ml, respectively) were numerically higher than observed previously in a pharmacokinetic analysis of the global population in APHINITY and in patients treated in the metastatic setting. The geometric mean ratio and corresponding 90% confidence interval for trastuzumab Cmax and Cmin in the presence (n = 15) or absence (n = 17) of pertuzumab were 104.6 (91.09-120) and 98.23 (84.58-114), respectively, indicating no apparent impact of pertuzumab on the pharmacokinetics of trastuzumab. Increases in pertuzumab Cmax and Cmin were not associated with an increase in adverse events. The APHINITY Chinese pharmacokinetic substudy analysis supports the dosing regimen for pertuzumab (840 mg loading dose followed by 420 mg maintenance doses every 3 weeks administered by intravenous infusion) in a Chinese HER2-positive early breast cancer patient population.

A phase 2 basket trial of combination therapy with trastuzumab and pertuzumab in patients with solid cancers harboring human epidermal growth factor receptor 2 amplification (JUPITER trial)

INTRODUCTION

Human epidermal growth factor receptor 2 (HER2) gene amplification and mutations have emerged as oncogenic drivers and therapeutic targets not limited to breast and gastric cancers, but also in a variety of cancers. However, even if an actionable gene alteration is found, the incidence of HER2 amplification in these cancers is less than 5%. It is too difficult to conduct a conventional randomized, controlled trial in a rare fraction. Therefore, we have designed a organ-agnostic basket study, which covers a variety of solid cancers harboring HER2 amplification, in 1 study protocol.

METHODS/DESIGN

This trial is a multicenter, single-arm, basket phase 2 study in Japan. Patients with solid cancers harboring HER2 amplification that have progressed with standard treatment, or rare cancers for which there is no standard treatment, will be eligible. Target cancers include bile duct, urothelial, uterine, ovarian, and other solid cancers where HER2 amplification is detected by comprehensive genomic profiling using next-generation sequencing technology. A total of 38 patients will be treated with combination therapy with trastuzumab and pertuzumab every 3 weeks until disease progression, unmanageable toxicity, death, or patient refusal. The primary endpoint is the objective response rate, and secondary endpoints are progression-free survival, overall survival, and duration of response.

DISCUSSION

The aim of this trial is to evaluate the safety and efficacy of combination therapy with trastuzumab and pertuzumab in patients with locally advanced or metastatic, solid cancers harboring HER2 amplification. Instead of focusing on 1 organ type, our trial design uses a basket study focusing on HER2 amplification, regardless of the site or origin of the cancer. The results of our study will advance clinical and scientific knowledge concerning the treatment of locally advanced, rare solid cancers harboring HER2 amplification, using the combination of trastuzumab and pertuzumab.

TRIAL REGISTRATION

This trial was registered in Japan Registry of Clinical Trials (jCRT) on February 25, 2019, as jRCT2031180150.

New HER2-negative breast cancer subtype responsive to anti-HER2 therapy identified

Purpose

HER2 signaling functional activity may be important to measure in addition to HER2 protein quantification when identifying patients eligible for HER2 therapies. A HER2 Signaling Function (CELx HSF) Test for HER2-negative patients uses patient’s live tumor cells on a biosensor to identify patients with abnormally high HER2-related signaling (HSFs+) likely to respond to anti-HER2 therapies.

Methods

The CELx HSF test was employed to: (1) characterize the sensitivity and specificity of the test to detect abnormal levels of HER2 signaling; (2) evaluate the inhibitory effectiveness of five different anti-HER2 therapies; (3) assess the correlation between CELx HSF test detection of abnormal HER2 signaling and response to HER2 therapy using xenograft models; and (4) confirm the prevalence of abnormal HER2 signaling amongst HER2-negative breast cancer patients (HER2−/HSFs+).

Results

HER2−/HSFs+ breast cancer patient samples were identified and showed sensitivity to five approved anti-HER2 therapies. Xenograft studies using both HER2+ and HER2− cell lines confirmed that CELx HER2 signaling status better predicts HER2 inhibitor efficacy than HER2 receptor status. In a study of 114 HER2-negative breast tumor patient samples, 27 (23.7%; 95% CI = 17–32%) had abnormal HER2 signaling (HSFs+). A ROC curve constructed with this dataset projects the CELx HSF Test would have greater than 90% sensitivity and specificity to detect the HER2−/HSFs+ patient population.

Conclusions

The CELx HSF test is a well-characterized functional biomarker assay capable of identifying dynamic HER2-driven signaling dysfunction in tumor cells from HER2-negative breast cancer patients. This test has demonstrated efficacy of various HER2 targeted therapies in live tumor cells from the HSFs+ population and correlated the test result to HER2 drug response in mouse xenograft studies. The proportion of HER2-negative breast cancer patients found to have abnormal HER2 signaling in a 114 patient sample study, 20–25%, is significant. A clinical trial to evaluate the efficacy of anti-HER2 therapies in this patient population is warranted.

Electronic supplementary material

The online version of this article (10.1007/s00432-020-03144-7) contains supplementary material, which is available to authorized users.

Pharmacokinetic and exposure-response analysis of pertuzumab in patients with HER2-positive metastatic gastric or gastroesophageal junction cancer

PURPOSE

To characterize the pharmacokinetics (PK) of pertuzumab and trastuzumab in patients with HER2-positive metastatic gastric or gastroesophageal junction cancer in the randomized, double-blind, phase III JACOB study (NCT01774786), and to evaluate the appropriateness of the pertuzumab regimen in these patients.

METHODS

Patients received 840 mg intravenous pertuzumab or placebo plus trastuzumab q3w and chemotherapy. Pertuzumab and trastuzumab were administered until disease progression or unacceptable toxicity. Chemotherapy was administered for up to six cycles or disease progression or unacceptable toxicity. Serum concentrations of pertuzumab and trastuzumab were measured. Pertuzumab PK was characterized across treatment cycles. The impact of anti-drug antibodies (ADAs) on pertuzumab PK and the impact of pertuzumab on trastuzumab PK were assessed. An exploratory exposure-efficacy analysis was also conducted.

RESULTS

In total, 374 patients in the pertuzumab arm had evaluable PK data. The mean observed pertuzumab steady-state serum trough (minimum) concentration (Cmin,ss) ± standard deviation was 114 ± 51.8 μg/mL. The target pertuzumab Cmin,ss of ≥ 20 μg/mL was reached in 99.3% of patients at Cycle 5 (steady state) and beyond. Greater than 90% of patients were above the PK target right after the first pertuzumab dose. There was no apparent impact of ADAs on pertuzumab PK nor of pertuzumab on trastuzumab PK. There were no differences in overall survival across Cycle 1 pertuzumab (Cmin) or Cycle 5 pertuzumab (Cmin,ss) exposure quartiles.

CONCLUSIONS

Pertuzumab exposure in JACOB was consistent with prior studies in advanced gastric cancer and breast cancer. The 840 mg q3w dose allowed the majority of patients in JACOB to achieve target pertuzumab concentrations and appears to be an appropriate dose selection.

An in vitro FcRn- dependent transcytosis assay as a screening tool for predictive assessment of nonspecific clearance of antibody therapeutics in humans

A cell-based assay employing Madin–Darby canine kidney cells stably expressing human neonatal Fc receptor (FcRn) heavy chain and β2-microglobulin genes was developed to measure transcytosis of monoclonal antibodies (mAbs) under conditions relevant to the FcRn-mediated immunoglobulin G (IgG) salvage pathway. The FcRn-dependent transcytosis assay is modeled to reflect combined effects of nonspecific interactions between mAbs and cells, cellular uptake via pinocytosis, pH-dependent interactions with FcRn, and dynamics of intracellular trafficking and sorting mechanisms. Evaluation of 53 mAbs, including 30 marketed mAb drugs, revealed a notable correlation between the transcytosis readouts and clearance in humans. FcRn was required to promote efficient transcytosis of mAbs and contributed directly to the observed correlation. Furthermore, the transcytosis assay correctly predicted rank order of clearance of glycosylation and Fv charge variants of Fc-containing proteins. These results strongly support the utility of this assay as a cost-effective and animal-sparing screening tool for evaluation of mAb-based drug candidates during lead selection, optimization, and process development for desired pharmacokinetic properties.

Pharmacokinetic and exploratory exposure-response analysis of pertuzumab in patients with operable HER2-positive early breast cancer in the APHINITY study

Purpose

To characterize the pharmacokinetics (PK) of, and perform an exploratory exposure–response (E–R) analysis for, pertuzumab in patients with HER2-positive early breast cancer (EBC) within the APHINITY study (NCT01358877, BIG 4–11/BO25126/TOC4939G).

Methods

A previously developed pertuzumab two-compartment linear population pharmacokinetic (popPK) model was subjected to external validation to examine appropriateness for describing pertuzumab concentrations from the APHINITY study. Pharmacokinetic drug–drug interactions (DDIs) between pertuzumab, trastuzumab, and chemotherapy were assessed by comparing observed serum or plasma C_max, C_min, and AUC_last geometric mean ratios with 90% CIs. Predictions of pertuzumab C_max,ss, C_min,ss, and AUC_ss were derived from individual parameter estimates and used in an exploratory E–R analysis.

Results

Using data from 72 patients, based on goodness-of-fit, the popPK model was deemed appropriate for predictions of individual exposures for subsequent comparisons to historical data, assessment of DDIs, and E–R analyses. No evidence of DDIs for pertuzumab on trastuzumab, trastuzumab on pertuzumab, or pertuzumab on chemotherapy PK was observed. Analyses of differences in exposure between patients with and without invasive disease-free survival events did not indicate improved efficacy with increased exposure. Overall Grade ≥ 3 diarrhea prevalence was higher with pertuzumab versus placebo, but was not greater with increasing pertuzumab exposure. No apparent E–R relationship was suggested with respect to other grade ≥ 3 AEs.

Conclusion

Overall, the limited available data from this exploratory study suggest that no dose adjustments are needed for pertuzumab when administered in combination with trastuzumab and an EBC chemotherapy regimen.

Electronic supplementary material

The online version of this article (10.1007/s00280-019-03826-1) contains supplementary material, which is available to authorized users.

Cell-specific biomarkers and targeted biopharmaceuticals for breast cancer treatment

Breast cancer is the second leading cause of cancer death among women, and its related treatment has been attracting significant attention over the past decades. Among the various treatments, targeted therapy has shown great promise as a precision treatment, by binding to cancer cell-specific biomarkers. So far, great achievements have been made in targeted therapy of breast cancer. In this review, we first discuss cell-specific biomarkers, which are not only useful for classification of breast cancer subtyping but also can be utilized as goals for targeted therapy. Then, the innovative and generic-targeted biopharmaceuticals for breast cancer, including monoclonal antibodies, non-antibody proteins and small molecule drugs, are reviewed. Finally, we provide our outlook on future developments of biopharmaceuticals, and provide solutions to problems in this field.