The European Medicines Agency Review of Pertuzumab for the treatment of adult patients with HER2-positive metastatic or locally recurrent unresectable breast cancer: summary of the scientific assessment of the committee for medicinal products for human use

Comparing efficacy and safety of P013, a proposed pertuzumab biosimilar, with the reference product in HER2-positive breast cancer patients: a randomized, phase III, equivalency clinical trial

BACKGROUND

Breast cancer is the most frequently diagnosed cancer and the leading reason for cancer-related death among women. Neoadjuvant treatment with dual-HER2 (human epidermal growth factor receptor 2) blockade has shown promising effects in this regard. The present study aimed to compare the efficacy and safety of a proposed pertuzumab biosimilar with the reference pertuzumab.

METHODS

This randomized, phase III, multicenter, equivalency clinical trial was conducted on chemotherapy-naive women with HER2-positive breast cancer. Patients were randomly assigned (1:1) to receive six cycles of either P013 (CinnaGen, Iran) or the originator product (Perjeta, Roche, Switzerland) along with trastuzumab, carboplatin, and docetaxel every 3 weeks. Patients were stratified by cancer type (operable, locally advanced, inflammatory) and hormone receptor status. The primary endpoint was breast pathologic complete response (bpCR). Secondary endpoints included comparisons of total pCR, overall response rate (ORR), breast-conserving surgery (BCS), safety, and immunogenicity.

RESULTS

Two hundred fourteen patients were randomized to treatment groups. bpCR rate in the per-protocol population was 67.62% in the P013 and 71.57% in the reference drug groups. Based on bpCR, P013 was equivalent to the reference pertuzumab with a mean difference of - 0.04 (95% CI: - 0.16, 0.09). Secondary endpoints were also comparable between the two groups.

CONCLUSIONS

The proposed biosimilar P013 was equivalent to the reference product in terms of efficacy. The safety of both medications was also comparable.

Risks of molecular targeted therapies to fertility and safety during pregnancy: a review of current knowledge and future needs

INTRODUCTION

As the population of young cancer survivors is increasing and a trend toward postponing pregnancy later in life is reported, more efforts are focused toward understanding treatment-induced sequelae, in particular, the effects of cancer and/or treatment on fertility.

AREA COVERED

Whereas the fertility risk of cytotoxic agents for both men and women is well recognized, the impact of molecular-targeted therapy (MTT) on fertility parameters, their teratogenic potential and pregnancy outcome/management in case of an accidental exposure are not established. We update available clinical data on the impact of new MTTs on fertility in both sexes, their potential teratogenic effects and the outcome of pregnancy during accidental exposure. Agents are categorized by class and the potential relevance of their target signaling pathways to gonadal maturation.

EXPERT OPINION

The majority of MTTs have worrying preclinical data discouraging their use during pregnancy and reinforcing the idea that they can induce impairment in gonadal function. However, it does not mean that all MTTs result in permanent infertility and that they should be completely avoided during pregnancy. The current review provides a critical evaluation on the most commonly used MTTs, offering a possible guide for clinicians.

DLC2 operates as a tumor suppressor gene in breast cancer via the RhoGTPase pathway

Deleted in liver cancer 2 (DLC2) is a tumor suppressor, associated with various types of cancer. The aim of the present study was to analyze the expression of DLC2 in breast cancer, its clinical significance and its effect on breast cancer cell behavior. The expression of DLC2 was evaluated by immunohistochemistry in 131 cases of breast cancer. Associations among DLC2 expression and clinicopathological features were analyzed, and its effects on proliferation, motility, migration and invasion in DLC2-knockdown breast cancer cell lines were observed. The results indicated that DLC2 was expressed in 42.75% of breast cancer cases (56/131) and in 79.39% of adjacent normal tissues (104/131). Lower expression of DLC2 in breast cancer was associated with tumor differentiation (P<0.001), lymph node metastasis (P<0.001) and poor prognosis (P<0.001). The silencing of the DLC2 gene in human breast cancer cell indicated an increased number of cells entering S phase, and increased abilities of clone formation, cell migration and invasion. Downregulated expression of DLC2 was associated with activated Ras homolog family member A and decreased Rac family small GTPase 1, cell division cycle 42 and Rho-associated protein kinase-2 expression levels, indicating that DLC2 may serve a regulatory function in breast cancer cell proliferation and invasion via the RhoGTPase pathway. The results of the present study suggested that DLC2 serves as a suppressor gene in the development of breast cancer and may be a prognostic marker for patients with breast cancer.

Moving Breast Cancer Therapy up a Notch

Breast cancer is the second most common malignancy, worldwide. Treatment decisions are based on tumor stage, histological subtype, and receptor expression and include combinations of surgery, radiotherapy, and systemic treatment. These, together with earlier diagnosis, have resulted in increased survival. However, initial treatment efficacy cannot be guaranteed upfront, and these treatments may come with (long-term) serious adverse effects, negatively affecting a patient's quality of life. Gene expression-based tests can accurately estimate the risk of recurrence in early stage breast cancers. Disease recurrence correlates with treatment resistance, creating a major need to resensitize tumors to treatment. Notch signaling is frequently deregulated in cancer and is involved in treatment resistance. Preclinical research has already identified many combinatory therapeutic options where Notch involvement enhances the effectiveness of radiotherapy, chemotherapy or targeted therapies for breast cancer. However, the benefit of targeting Notch has remained clinically inconclusive. In this review, we summarize the current knowledge on targeting the Notch pathway to enhance current treatments for breast cancer and to combat treatment resistance. Furthermore, we propose mechanisms to further exploit Notch-based therapeutics in the treatment of breast cancer.

Pertuzumab, trastuzumab and taxane-based treatment for visceral organ metastatic, trastuzumab-naïve breast cancer: real-life practice outcomes

PURPOSE

In this study, we aimed to describe the real-life practice outcomes of pertuzumab-trastuzumab-taxane (PTT) combination in visceral organ metastatic, trastuzumab-naive breast cancer (BC) patients.

METHODS

This study was conducted by Turkish Oncology Group and included 317 patients' data from 36 centers.

RESULTS

Median age was 51 (22-82). Median PFS was 28.5 months, while median OS was 40.3 months. Patients with brain metastases (n: 13, 4.1%) had worse PFS (16.8 m vs. 28.5 m; p = 0.002) and OS (26.7 m vs. 40.3 m; p = 0.009). Patients older than 65 years of age (n: 42, 13.2%) had significantly lower OS results (19.8 m vs. 40.3 m; p = 0.01). Two hundred sixty-eight patients (86.7%) received docetaxel while 37 patients (11.7%) received paclitaxel. PFS and OS were similar between taxane groups. In eight patients (2.5%), 5-40% ejection fraction decrement from baseline was detected without any clinical sign of heart failure.

CONCLUSIONS

Our RLP trial included only visceral metastatic, trastuzumab-naïve BC patients including cases with brain involvement who received PTT combination in the first-line treatment. Regardless of negative prognostic characteristics, our results are in parallel with pivotal trial. Further strategies for brain metastasis should be developed to improve outcomes despite encouraging results with PTT treatment. Taxane selection can be personalized and endocrine maintenance may further improve outcomes after taxanes were discontinued. To our knowledge, this is the largest scale real-life clinical practice study of pertuzumab-trastuzumab-taxane therapy to date.

Predictive blood plasma biomarkers for EGFR inhibitor-induced skin rash

Epidermal growth factor receptor overexpression in human cancer can be effectively targeted by drugs acting as specific inhibitors of the receptor, like erlotinib, gefitinib, cetuximab and panitumumab. A common adverse effect is a typical papulopustular acneiform rash, whose occurrence and severity are positively correlated with overall survival in several cancer types. We studied molecules involved in epidermal growth factor receptor signaling which are quantifiable in plasma, with the aim of identifying biomarkers for the severity of rash. With a predictive value for the rash these biomarkers may also have a prognostic value for survival and disease outcome.

The concentrations of amphiregulin, hepatocyte growth factor (HGF) and calcidiol were determined by specific enzyme-linked immunosorbent assays in plasma samples from 211 patients.

We observed a significant inverse correlation between the plasma concentration of HGF and overall survival in patients with an inhibitor-induced rash (p-value = 0.0075; mean overall survival low HGF: 299 days, high HGF: 240 days) but not in patients without rash. The concentration of HGF was also significantly inversely correlated with severity of rash (p-value = 0.00124).

High levels of HGF lead to increased signaling via its receptor MET, which can activate numerous pathways which are normally also activated by epidermal growth factor receptor. Increased HGF/MET signaling might compensate the inhibitory effect of epidermal growth factor receptor inhibitors in skin as well as tumor cells, leading to less severe skin rash and decreased efficacy of the anti-tumor therapy, rendering the plasma concentration of HGF a candidate for predictive biomarkers.

The incidence and management of cutaneous adverse events of the epidermal growth factor receptor inhibitors

Overexpression of the epidermal growth factor receptor (EGFR) is found in many cancers, including those of the head and neck area, non-small-cell lung cancer, and colorectal, cervical, prostate, breast, ovary, stomach, and pancreatic cancer. The EGFR inhibitors are used at present in the treatment of such cancers. Skin lesions that develop during and after cancer treatment may be due to specific cytostatics, molecular-targeted drugs, radiation therapy, complementary therapy, or the cancer itself, and hence knowledge is essential to distinguish between them. The mechanism through which skin toxicity arises during treatment with EGFR inhibitors is not well known, but seems to be due to the modification of the RAS/RAF/MEK/ERK signal path associated with its activation, which results in the similarity between the adverse effects of EGFR inhibitors and the treatment of melanoma with BRAF and MEK inhibitors. The most common side effects are pruritus, xerosis, papulopustular rash, hand-foot skin reaction, alopecia and dystrophy of the hair, and paronychia. This work presents options for prevention and suggestions for managing these adverse events, which are of importance in the care of patients undergoing oncological treatment.

DNA Mutations May Not Be the Cause of Cancer

Cancer is the most challenging disease of our time with increasing numbers of new cases each year, worldwide. Great achievements have been reached in cancer research through deep sequencing which helped define druggable targets. However, the still-evolving targeted therapy suffers resistance suggesting that DNA mutations considered as drivers may not have a role in tumor initiation. The present work discusses the role of DNA mutations as drivers and passengers in cancer initiation and development. First, it is important to discern the role of these DNA mutations as initiating events causing cancer or as contributors crucial for the development of a tumor once it has initiated. Second, breast cancer shown here illustrates how identification of DNA mutations in cancerous cells has influenced our approach for anti-cancer drug design. The cancer trilogy we have reached and described as: initial drug; resistance/recurrence; drug/treatment combinations, calls for a paradigm shift. To design more effective cancer drugs with durable and positive outcome, future cancer research needs to move beyond the sequencing era and explore changes which are taking place in cancer cells at levels other than the DNA. Evolutionary constraints may be acting as a barrier to preserve the human species from being transformed and, for that matter, all multi-cellular species which can incur cancer. Furthermore, mutations in the DNA do occur and for a multitude of reasons but without necessarily causing cancer. New directions will draw themselves when more focus is given to the event responsible for the switch of a cell from normalcy to malignancy. Until then, targeted therapy will certainly continue to improve the outcome of patients; however, it is unlikely to eradicate breast cancer depicted here.

Safety and efficacy evaluation of pertuzumab in patients with solid tumors

BACKGROUND

The development of targeted therapies benefits patients with certain markers in the treatment of breast cancer. Pertuzumab is a novel humanized monoclonal antibody that blocks human epidermal growth factor receptor 2 (HER2) dimerization. The Food and Drug Administration has approved pertuzumab in combination with trastuzumab and docetaxel for the treatment of patients with HER2-positive metastatic breast cancer.

METHODS

To assess the safety and efficacy profile of pertuzumab, we searched PubMed and Embase (articles from January 1966 to January 2015) using the keyword "pertuzumab".

RESULTS

Fourteen eligible studies were included in our final analysis. From the results of our analysis, diarrhea (56.9%, 95% confidence interval [CI] 49.6%-63.9%), nausea (34.0%, 95% CI 27.7%-40.8%), and rash (25.6%, 95% CI 20.8%-31.0%) were the most common adverse effects in pertuzumab alone and pertuzumab-based therapies. Based on randomized controlled clinical trials, diarrhea (odds ratio [OR] 2.310, 95% CI 1.818-2.936), rash (OR 1.848, 95% CI 1.094-3.122), and febrile neutropenia (OR 1.672, 95% CI 1.130-2.474) were of statistical significance, which meant that pertuzumab played a prominent role in the incidence of diarrhea. Meanwhile, pertuzumab showed its effective role in cancer control and lifetime prolongation.

CONCLUSION

In conclusion, considering that the common adverse effects for pertuzumab are gastrointestinal and skin toxicities, which are easier to handle than other toxicities, pertuzumab is a safe and effective drug for patients with solid tumors.

Pathological Complete Response to Neoadjuvant Trastuzumab Is Dependent on HER2/CEP17 Ratio in HER2-Amplified Early Breast Cancer

Purpose: To evaluate whether pathologic complete response (pCR) to neoadjuvant trastuzumab is dependent on the level of HER2 amplification.Experimental Design: 114 HER2-overexpressing early breast cancer patients who had received neoadjuvant trastuzumab were included in this study. Absolute HER2 and chromosome 17 centromere (CEP17) were measured by in situ hybridization analysis, and associations were examined between HER2/CEP17 ratio and tumor pCR status (commonly defined by ypT0 ypN0, ypT0/is ypN0, and ypT0/is).Results: In trastuzumab-treated patients, ypT0 ypN0 was achieved in 69.0% of patients with high-level amplification (HER2/CEP17 ratio > 6), but only in 30.4% of tumors with low-level amplification (ratio ≤ 6; P = 0.001). When pCR was defined by ypT0/is ypN0 or ypTis, 75.9% and 82.8% of tumors with high-level amplification had a complete response, whereas only 39.1%, and 38.3% with low-level amplification achieved pCR (P = 0.002 and P < 0.001, respectively). Logistic regression revealed that tumors with high-level amplification had a significantly higher probability achieving ypT0 ypN0 (OR, 5.08; 95% confidence interval, 1.86-13.90; P = 0.002) than tumors with low-level amplification, whereas no other clinicopathologic parameters were predictive of pCR. The association between high-level HER2 amplification and pCR was almost exclusively confined to hormone receptor (HR)-positive tumors (ypT0 ypN0: 62.5% vs. 24.0%, P = 0.014; ypT0/is ypN0: 75.0% vs. 28.0%, P = 0.005; and ypT0/is: 87.5% vs. 28.0%, P < 0.001), and was largely absent in HR-negative tumors.Conclusions: An HER2/CEP17 ratio of >6 in the pretherapeutic tumor biopsy is associated with a significantly higher pCR rate, particularly in HER2/HR copositive tumors, and can be used as a biomarker to predict response before neoadjuvant trastuzumab is initiated. Clin Cancer Res; 23(14); 3676-83. ©2017 AACR.

Biological agents: what they are, how they affect oral health and how they can modulate oral healthcare

Biological agents - biologics, biologicals or biopharmaceuticals - are any medicinal product manufactured in, or extracted from, a biological source. They are often generated by DNA recombinant biotechnology and several dozen therapeutic monoclonal antibodies (mAbs) are now marketed for a variety of indications, increasingly in the management of inflammatory immune-mediated disorders, transplantation rejection and cancer treatments. Immunomodulatory mAbs are expensive, must be given by injection or infusion and can have adverse effects but are increasingly used and can be highly effective agents. This paper reviews these agents and their increasing relevance to oral science and healthcare.

The combination of trastuzumab and pertuzumab administered at approved doses may delay development of trastuzumab resistance by additively enhancing antibody-dependent cell-mediated cytotoxicity

Although the recently concluded CLEOPATRA trial showed clinical benefits of combining trastuzumab and pertuzumab for treating HER2-positive metastatic breast cancer, trastuzumab monotherapy is still the mainstay in adjuvant settings. Since trastuzumab resistance occurs in over half of these cancers, we examined the mechanisms by which treatment of intrinsically trastuzumab-resistant and -sensitive tumors can benefit from the combination of these antibodies. F(ab′)₂ of both trastuzumab and pertuzumab were generated and validated in order to separately analyze antibody-dependent cell-mediated cytotoxicity (ADCC)-based and direct biological effects of the antibodies. Compared to monotherapy, combination of the two antibodies at clinically permitted doses enhanced the recruitment of natural killer cells responsible for ADCC, and significantly delayed the outgrowth of xenografts from intrinsically trastuzumab-resistant JIMT-1 cells. Antibody dose-response curves of in vitro ADCC showed that antibody-mediated killing can be saturated, and the two antibodies exert an additive effect at sub-saturation doses. Thus, the additive effect in vivo indicates that therapeutic tissue levels likely do not saturate ADCC. Additionally, isobole studies with the in vitro trastuzumab-sensitive BT-474 cells showed that the direct biological effect of combined treatment is additive, and surpasses the maximum effect of either monotherapy. Our results suggest the combined therapy is expected to give results that are superior to monotherapy, whatever the type of HER2-positive tumor may be. The combination of both antibodies at maximum clinically approved doses should thus be administered to patients to recruit maximum ADCC and cause maximum direct biological growth inhibition.

The use of combinations of monoclonal antibodies in clinical oncology

Treatment with monoclonal antibodies is becoming increasingly important in clinical oncology. These antibodies specifically inhibit signaling pathways in tumor growth and/or induce immunological responses against tumor cells. By combining monoclonal antibodies several pathways may be targeted simultaneously, potentially leading to additive or synergistic effects. Theoretically, antibodies are very suitable for use in combination therapy, because of limited overlapping toxicity and lack of pharmacokinetic interactions. In this article an overview is given of preclinical and clinical data on twenty-five different combinations of antibodies in oncology. Some of these combinations have proven clinical benefit, for example the combination of trastuzumab and pertuzumab in HER2-positive breast cancer, which exemplifies an additive or synergistic effect on antitumor activity in clinical studies and the combination of nivolumab and ipilimumab, which results in significant increases in progression-free and overall survival in patients with advanced melanoma. However, other combinations may lead to unfavorable results, such as bevacizumab with cetuximab or panitumumab in advanced colorectal cancer. These combinations result in shorter progression-free survival and increased toxicity compared to therapy with a single antibody. In summary, the different published studies showed widely varying results, depending on the combination of antibodies, indication and patient population. More preclinical and clinical studies are necessary to unravel the mechanisms behind synergistic or antagonistic effects of combining monoclonal antibodies. Most research on combination therapies is still in an early stage, but it is expected that for several tumor types the use of combination therapy of antibodies will become standard of care in the near future.

Synthesis, characterization and targeting chemotherapy for ovarian cancer of trastuzumab-SN-38 conjugates

Antibody-drug conjugates (ADCs), combining monoclonal antibody with high cytotoxicity chemotherapeutic drug (warhead), have been successfully applied for clinical cancer therapy. Linker technology to select and design linker connecting warhead with antibody, is critical to the success of therapeutic ADCs. In this study, three kinds of linkers were designed to connect SN-38, the bioactive metabolite of the anticancer drug irinotecan (CPT-11), which is 100-1000 times more potent than CPT-11, with the anti-HER2 antibody trastuzumab to prepare three different ADC conjugates (T-SN38 A, B and C). Meanwhile, we compared the anti-ovarian cancer effect of these three T-SN38 conjugates with trastuzumab in vitro and in vivo. Our in vitro results showed that T-SN38 A, B and C (drug-to-antibody ratio, DAR=3.7, 3.2, 3.4) were 2 to 3 times as cytotoxic as SN-38, and the IC50 for these three conjugates on SKOV-3 cell line at 72 h were 5.2 ± 0.3, 4.4 ± 0.7, and 5.1 ± 0.4 nM respectively. In our in vivo studies, T-SN38 conjugates had well targeting ability for tumor tissue and all three of them had much higher anti-ovarian cancer potency than trastuzumab. Among of them, T-SN38 B, which coupled SN-38 with trastuzumab by a carbonate bond, has the best anti-ovarian cancer potency. In conclusion, the novel HER2-targeting ADCs T-SN38 have great potential for HER2-positive ovarian cancer. Moreover, the SN-38-Linkers designed in this study can also be used to connect with other antibodies for the therapy of other cancers.

Small molecule tyrosine kinase inhibitors of ErbB2/HER2/Neu in the treatment of aggressive breast cancer

The human epidermal growth factor receptor 2 (HER2) is a member of the erbB class of tyrosine kinase receptors. These proteins are normally expressed at the surface of healthy cells and play critical roles in the signal transduction cascade in a myriad of biochemical pathways responsible for cell growth and differentiation. However, it is widely known that amplification and subsequent overexpression of the HER2 encoding oncogene results in unregulated cell proliferation in an aggressive form of breast cancer known as HER2-positive breast cancer. Existing therapies such as trastuzumab (Herceptin®) and lapatinib (Tyverb/Tykerb®), a monoclonal antibody inhibitor and a dual EGFR/HER2 kinase inhibitor, respectively, are currently used in the treatment of HER2-positive cancers, although issues with high recurrence and acquired resistance still remain. Small molecule tyrosine kinase inhibitors provide attractive therapeutic targets, as they are able to block cell signaling associated with many of the proposed mechanisms for HER2 resistance. In this regard we aim to present a review on the available HER2 tyrosine kinase inhibitors, as well as those currently in development. The use of tyrosine kinase inhibitors as sequential or combinatorial therapeutic strategies with other HER family inhibitors is also discussed.