Phase I study of pulsatile 3-day administration of afatinib (BIBW 2992) in combination with docetaxel in advanced solid tumors

Multi-Targeting Anticancer Agents: Rational Approaches, Synthetic Routes and Structure Activity Relationship

We live in a world with complex diseases such as cancer which cannot be cured with one-compound one-target based therapeutic paradigm. This could be due to the involvement of multiple pathogenic mechanisms. One-compound-various-targets stratagem has become a prevailing research topic in anti-cancer drug discovery. The simultaneous interruption of two or more targets has improved the therapeutic efficacy as compared to the specific targeted based therapy. In this review, six types of dual targeting agents along with some interesting strategies used for their design and synthesis are discussed. Their pharmacology with various types of the molecular interactions within their specific targets has also been described. This assemblage will reveal the recent trends and insights in front of the scientific community working in dual inhibitors and help them in designing the next generation of multi-targeted anti-cancer agents.

Combined targeting EGFR and SRC as a potential novel therapeutic approach for the treatment of triple negative breast cancer

Background:

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited therapeutic options. Epidermal growth factor receptor (EGFR) has been shown to be over-expressed in TNBC and represents a rational treatment target.

Methods:

We examined single agent and combination effects for afatinib and dasatinib in TNBC. We then determined IC₅₀ and combination index values using Calcusyn. Functional analysis of single and combination treatments was performed using reverse phase protein array and cell cycle analysis. Finally, we determined the anticancer effects of the combination in vivo.

Results:

A total of 14 TNBC cell lines responded to afatinib with IC₅₀ values ranging from 0.008 to 5.0 µM. Three cell lines, belonging to the basal-like subtype of TNBC, were sensitive to afatinib. The addition of afatinib enhanced response to the five other targeted therapies in HCC1937 and HDQP1 cells. The combination of afatinib with dasatinib caused the greatest growth inhibition in both cell lines. The afatinib/dasatinib combination was synergistic and/or additive in 13/14 TNBC cell lines. Combined afatinib/dasatinib treatment induced G1 cell cycle arrest. Reverse phase protein array results showed the afatinib/dasatinib combination resulted in efficient inhibition of both pERK(T202/T204) and pAkt(S473) signalling in BT20 cells, which was associated with the greatest antiproliferative effects. High baseline levels of pSrc(Y416) and pMAPK(p38) correlated with sensitivity to afatinib, whereas low levels of B-cell lymphoma 2 (Bcl2) and mammalian target of rapamycin (mTOR) correlated with synergistic growth inhibition by combined afatinib and dasatinib treatment. In vivo, the combination treatment inhibited tumour growth in a HCC1806 xenograft model.

Conclusions:

We demonstrate that afatinib combined with dasatinib has potential clinical activity in TNBC but warrants further preclinical investigation.

Phase I dose-escalation trial of afatinib, an irreversible ErbB family blocker, in combination with gemcitabine or docetaxel in patients with relapsed or refractory solid tumors

Background Afatinib, an irreversible ErbB family blocker, has shown synergistic antitumor activity and manageable tolerability in combination with chemotherapy. This phase I study assessed oral afatinib plus intravenous gemcitabine or docetaxel in patients with relapsed/refractory solid tumors. Methods Patients received afatinib (30, 40, or 50 mg) plus gemcitabine (1000 or 1250 mg/m²) or docetaxel (60 or 75 mg/m²). Dose escalation proceeded via a 3 + 3 design until the maximum tolerated dose (MTD) was reached. Adverse events (AEs), pharmacokinetics and antitumor activity were also assessed. Results Dose-limiting toxicities during Cycle 1 were reported in 6/39 patients receiving afatinib/gemcitabine (most commonly diarrhea, thrombocytopenia and vomiting) and 16/54 patients receiving afatinib/docetaxel (most commonly febrile neutropenia and stomatitis). The MTDs were established as afatinib 40 mg/gemcitabine 1000 mg/m² and afatinib 30 mg/docetaxel 60 mg/m². The most common drug-related AEs were diarrhea, asthenia and rash with afatinib/gemcitabine, and diarrhea, asthenia and stomatitis with afatinib/docetaxel. No relevant pharmacokinetic interactions were observed for either combination. Both combinations demonstrated clinical activity and durable disease control at the MTDs. Compared with the MTD, higher response rates were achieved with afatinib 30 mg/docetaxel 75 mg/m² (28% vs 6%); however, this regimen was associated with problematic febrile neutropenia, an expected AE with docetaxel, that is often managed with growth factor support. Conclusions Afatinib/gemcitabine and afatinib/docetaxel demonstrated manageable safety profiles, with evidence of clinical efficacy at the MTDs. For afatinib/docetaxel, a dose level of afatinib 30 mg/docetaxel 75 mg/m² produced higher response rates. Trial registration: NCT01251653 ( ClinicalTrials.gov ).

Clinical Pharmacokinetics and Pharmacodynamics of Afatinib

Afatinib is an oral, irreversible ErbB family blocker that covalently binds to the kinase domains of epidermal growth factor receptor (EGFR), human EGFRs (HER) 2, and HER4, resulting in irreversible inhibition of tyrosine kinase autophosphorylation. Studies in healthy volunteers and patients with advanced solid tumours have shown that once-daily afatinib has time-independent pharmacokinetic characteristics. Maximum plasma concentrations of afatinib are reached approximately 2–5 h after oral administration and thereafter decline, at least bi-exponentially. Food reduces total exposure to afatinib. Over the clinical dose range of 20–50 mg, afatinib exposure increases slightly more than dose proportional. Afatinib metabolism is minimal, with unchanged drug predominantly excreted in the faeces and approximately 5 % in urine. Apart from the parent drug afatinib, the major circulation species in human plasma are the covalently bound adducts to plasma protein. The effective elimination half-life is approximately 37 h, consistent with an accumulation of drug exposure by 2.5- to 3.4-fold based on area under the plasma concentration–time curve (AUC) after multiple dosing. The pharmacokinetic profile of afatinib is consistent across a range of patient populations. Age, ethnicity, smoking status and hepatic function had no influence on afatinib pharmacokinetics, while females and patients with low body weight had increased exposure to afatinib. Renal function is correlated with afatinib exposure, but, as for sex and body weight, the effect size for patients with severe renal impairment (approximately 50 % increase in AUC) is only mildly relative to the extent of unexplained interpatient variability in afatinib exposure. Afatinib has a low potential as a victim or perpetrator of drug–drug interactions, especially with cytochrome P450-modulating agents. However, concomitant treatment with potent inhibitors or inducers of the P-glycoprotein transporter can affect the pharmacokinetics of afatinib. At a dose of 50 mg, afatinib does not have proarrhythmic potential.

The efficacy and toxicity of afatinib in advanced EGFR-positive non-small-cell lung cancer patients after failure of first-generation tyrosine kinase inhibitors: a systematic review and meta-analysis

BACKGROUND

The first generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, have become the standard first-line treatment for non-small-cell lung cancer (NSCLC) patients with EGFR mutation. However, there was no pooled analysis focused on the usage of the second-generation TKI, afatinib, in advanced EGFR-positive NSCLC patients after failure of first generation TKIs. Therefore, a meta-analysis was conducted to solve the above question.

METHODS

Electronic databases were searched for eligible literatures. ORR (objective response rate), DCR (disease controlled rate), PFS (progression-free survival), OS (overall survival) and primary grade 3/4 adverse events were pooled with the corresponding 95% confidence interval using R software. Sensitivity analyses and heterogeneity were quantitatively evaluated.

RESULTS

A total of 545 EGFR-positive patients were available for analysis from five studies after detailed screening from 909 relevant studies. The pooled ORR and DCR of afatinib in EGFR-positive patients after failure of the first generation EGFR-TKIs were 0.12 (0.08-0.19) and 0.60 (0.53-0.68), respectively. Besides, the 6 m-PFS rate, 1 y-PFS rate and 6 m-OS rate were 0.26 (0.22-0.30), 0.08 (0.06-0.10) and 0.74 (0.56-0.86). The grade 3/4 rate of diarrhea and that of skin deformity were 0.23 (0.10-0.46) and 0.14 (0.05-0.33), respectively. Sensitivity analyses revealed similar results with lower heterogeneity.

CONCLUSIONS

Considering the efficacy, toxicity and current availability, afatinib could be a therapeutic option for advanced EGFR mutated NSCLC patients after the failure of 1st-generation TKIs.

Preclinical and clinical studies on afatinib in monotherapy and in combination regimens: Potential impact in colorectal cancer

Targeting the epidermal growth factor receptor (EGFR) with monoclonal antibodies (mAbs) or tyrosine kinase inhibitors (TKI) has been an interesting therapeutic strategy because aberrant activation of this receptor plays an important role in the tumorgenesis of many cancer types, including colorectal cancer (CRC). After the initial promising results of EGFR-targeted therapies, therapeutic resistance is a major clinical problem. In order to overcome resistance to these EGFR-targeted therapies, new treatment options are necessary. In contrast to first generation EGFR inhibitors, afatinib (BIBW2992) is a second-generation irreversible ErbB family blocker that inhibits EGFR as well as HER2 and HER4. Consequently, treatment with afatinib may result in a distinct and more pronounced therapeutic benefit. Preclinical studies have reported promising results for afatinib in monotherapy as well as in combination with other drugs in CRC model systems. Furthermore, clinical studies examining afatinib as single agent and in combination therapy demonstrated manageable safety profile. Nevertheless, only limited antitumor activity has been observed in CRC patients. Although several combination treatments with afatinib have already been investigated, no optimal combination has been identified for CRC patients yet. As molecular tumor characteristics have gained increased importance in the choice of treatment, additional studies with biomarker-driven patient recruitment are required to further explore afatinib efficacy in CRC.

Afatinib in squamous cell carcinoma of the head and neck

INTRODUCTION

Recently new data on the efficacy of afatinib in head and neck squamous cell carcinoma (HNSCC) have been published.

AREAS COVERED

We searched the literature for published and ongoing studies with afatinib in HNSCC. Phase I data and results of phase II and III studies of afatinib in HNSCC are discussed. The maximum tolerated dose (MTD) of afatinib monotherapy with continuous administration was determined at 40 or 50 mg/day, rash and diarrhea being the principal dose-limiting toxicities. The MTD was lower when combined with chemotherapy. Studies with afatinib have been conducted or are ongoing both in the recurrent or metastatic (R/M) and in the locoregionally advanced (LA) HNSCC disease setting.

EXPERT OPINION

Comparable disease control and tumor shrinkage rates were observed with cetuximab and afatinib in HNSCC progressing after platinum-containing chemotherapy. In patients with R/M- Squamous cell carcinoma of the head and neck (SCCHN) who had progressed on/after first-line platinum-based therapy, afatinib induced significantly higher disease control rate, longer progression-free survival and improved patient-reported outcome compared to methotrexate. Randomized phase III trials studying the role of adjuvant afatinib after definitive or postoperative chemoradiation in LA-HNSCC are ongoing.

Next-Generation Covalent Irreversible Kinase Inhibitors in NSCLC: Focus on Afatinib

First-generation, reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), erlotinib and gefitinib, represented an important addition to the treatment armamentarium for non-small-cell lung cancer (NSCLC) patients with activating EGFR mutations. However, all patients inevitably develop acquired resistance to these agents, primarily due to secondary EGFR mutations, molecular aberrations affecting other signaling pathways, or transformation to small-cell histology. It was hypothesized that development of second-generation TKIs with broader inhibitory profiles could confer longer-lasting clinical activity and overcome acquired resistance to first-generation inhibitors. Here, we review the development of afatinib, an irreversible ErbB family blocker that potently inhibits signaling of all homodimers and heterodimers formed by the EGFR, human epidermal growth factor receptor (HER)-2, HER3, and HER4 receptors. In two phase III trials in patients with EGFR mutation-positive NSCLC, first-line afatinib significantly improved progression-free survival (PFS) and health-related quality of life versus standard-of-care chemotherapy. Moreover, in preplanned sub-analyses, afatinib significantly improved overall survival in patients harboring EGFR Del19 mutations. Afatinib has also demonstrated clinical activity in NSCLC patients who had progressed on erlotinib/gefitinib, particularly when combined with cetuximab, and offers ‘treatment beyond progression’ benefit when combined with paclitaxel versus chemotherapy alone. Furthermore, a recent phase III study demonstrated that PFS was significantly improved with afatinib versus erlotinib for the second-line treatment of patients with squamous cell carcinoma of the lung. The activity of afatinib in both first-line and relapsed/refractory settings may reflect its ability to irreversibly inhibit all ErbB family members. Afatinib has a well-defined safety profile with characteristic gastrointestinal (diarrhea, stomatitis) and cutaneous (rash/acne) adverse events.

Afatinib-based combination regimens for the treatment of solid tumors: rationale, emerging strategies and recent progress

In oncology, there is a clinical need for novel combination therapy regimens that maximize efficacy and delay resistance to individual treatment modalities. Given the role of aberrant ErbB receptor signaling in the pathogenesis of many human cancers, there is rationale for incorporating afatinib, an irreversible pan-ErbB tyrosine kinase inhibitor, into such combinations. This review focuses on: pharmacological properties of afatinib that facilitate its use in combination; preclinical rationale for the combination of afatinib with other agents; and recently completed, and ongoing, clinical trials of afatinib-based combinations across tumor types. Based on these data, we emphasize a number of areas of high unmet medical need that could benefit from afatinib-based combinations, including patients with relapsed/refractory non-small-cell lung cancer.

Functionalized gold nanoparticles improve afatinib delivery into cancer cells

OBJECTIVES

A drug delivery system based on colloidal pegylated gold nanoparticles (PEGAuNPs) conjugated with the tyrosine kinase inhibitor afatinib was designed and tested for enhancing the drug activity against pancreatic and NSCLC cells.

METHODS

PEGAuNPs were synthesized and characterized physicochemically. Confocal imaging was performed to evaluate the nanoparticle (NP) internalization in cancer cells. For cell-cycle distribution analysis, conjugated NPs and afatinib alone were incubated with cells and alterations on the cell-cycle profile subsequently analyzed by total DNA staining. Cancer cell survival and growth inhibition following incubation with afatinib and PEGAuNPs-afatinib (concentrations between 0.007 and 0.500 µM afatinib) were evaluated.

RESULTS

A higher cellular uptake of PEGAuNPs was observed by cancer cells. Our data suggest an efficient conjugation of PEGAuNPs with the drug, enhancing the afatinib activity in comparison with afatinib alone. In fact, IC50 and GI50 results obtained show that the PEGAuNPs-afatinib conjugate is ca. 5 and 20 times more potent than afatinib alone in S2-013 and A549 cell lines, respectively.

CONCLUSIONS

Conjugating PEGAuNPs with afatinib is a promising antitumor delivery system for cancer therapy as it improves drug efficacy, allowing a reduction in drug dose used and minimizing possible toxicity-related side effects.

A phase I study of daily afatinib, an irreversible ErbB family blocker, in combination with weekly paclitaxel in patients with advanced solid tumours

BACKGROUND

This phase I study evaluated afatinib, an irreversible ErbB family blocker, plus paclitaxel in patients with advanced solid tumours likely to express human epidermal growth factor receptor (HER1/EGFR) or HER2.

METHODS

Oral afatinib was combined with intravenous paclitaxel (80mg/m(2); days 1, 8 and 15 every four weeks) starting at 20mg once daily and escalated to 40 and 50mg in successive cohorts of ⩾3 patients. The primary objective was to determine the maximum tolerated dose (MTD) of afatinib combined with paclitaxel. Secondary objectives included safety, pharmacokinetics and antitumour activity.

RESULTS

Sixteen patients were treated. Dose-limiting toxicities with afatinib 50mg were fatigue and mucositis. The MTD was determined as afatinib 40mg with paclitaxel 80mg/m(2), which proved tolerable with repeated dosing. Frequent adverse events (AEs) included diarrhoea (94%), fatigue (81%), rash/acne (81%), decreased appetite (69%) and inflammation of mucosal membranes (69%); no grade 4 treatment-related AEs were observed. Five (31%) confirmed partial responses were observed in patients with non-small cell lung cancer (n=3), oesophageal cancer and cholangiocarcinoma; eight (50%) patients remained on study for ⩾6months. Pharmacokinetic parameters of afatinib and paclitaxel were similar for single administration or in combination.

CONCLUSIONS

The MTD and recommended phase II dose of once-daily afatinib combined with paclitaxel 80mg/m(2) (days 1, 8 and 15 every four weeks) was 40mg. AEs at or below this dose were generally manageable with repeated dosing. No pharmacokinetic interactions were observed. This combination demonstrated promising antitumour activity.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00809133.

Afatinib and lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) have an established role in the treatment of non-small-cell lung cancer (NSCLC). First-generation reversible ATP-competitive EGFR-TKIs are approved for the initial treatment of patients with EGFR mutation-positive advanced NSCLC. Afatinib is an irreversible second-generation EGFR-TKI with potent preclinical activity against EGFR (wild type and mutant), HER2, HER4 and EGFR-mutant NSCLC with acquired resistance to reversible EGFR-TKI. LUX-Lung 3 trial demonstrated superiority of afatinib to cisplatin and pemetrexed in the frontline treatment of treatment-naïve patients with advanced adenocarcinoma of the lung and EGFR mutation. Based on these results, afatinib was recently approved for the first-line treatment of NSCLC patients with EGFR mutation. This article summarizes current status of preclinical and clinical development of afatinib in NSCLC.

The Potential of panHER Inhibition in Cancer

Purpose: Hyper-activation of the HER (erbB) family receptors, HER 1-4, leads to up-regulation of the three vital signaling pathways: mitogen activated protein kinase, phosphoinositide 3-kinase/AKT, and Janus kinase/signal transducer and activator of transcription pathways. Blocking HER1/EGFR has a limited anticancer effect due to either secondary mutation e.g., T790M or by-pass signaling of other HER members. The emergence of an anti-panHER approach to blockade of these pathways as a cancer treatment may provide a solution to this resistance. This review aimed to provide an overview of the HER signaling pathways and their involvement in tumor progression and examine the current progress in panHER inhibition.

Methods: Recent literature associated with HER signaling pathways and panHER inhibition was reviewed through PubMed and Medline database, followed by critical comparison and analysis.

Results: Pre-clinical studies and clinical trials of panHER inhibitors show promising results, and the potential to improve patient outcomes in solid cancers.

Conclusion: The use of panHER inhibitors in cancers with HER-family hyper-activation, such as other epithelial cancers and sarcoma, is a new direction to research and has potential in clinical cancer therapy in the future.

Afatinib for the treatment of advanced non-small-cell lung cancer

INTRODUCTION

The inhibition of the epidermal growth factor receptor (EGFR) through tyrosine kinase inhibitors (TKIs) represents an effective strategy for EGFR-mutated NSCLC. Afatinib is an irreversible erythroblastosis oncogene B (ErbB) family blocker, able to inhibit the kinase domains of EGFR, HER2 and HER4, and the transphosphorylation of ErbB3 that has recently been approved in the United States for the first-line treatment of EGFR-mutated NSCLC and in Europe and Japan for the treatment of EGFR-mutated TKI-naive patients.

AREAS COVERED

The authors analyzed the pharmacology and the clinical activity of afatinib in NSCLC through a review of the literature. Trials exploring different settings have been reported, including LUX-Lung 3 and LUX-Lung 6, where the drug achieved better outcomes in terms of response rate, progression-free survival and quality of life compared with chemotherapy. The main toxicities of afatinib are gastrointestinal and skin-related adverse events.

EXPERT OPINION

Afatinib showed remarkable efficacy as a first-line treatment in the presence of common EGFR mutations. Afatinib showed some activity in NSCLC with acquired resistance to EGFR TKIs, although, currently, its efficacy after the failure of erlotinib or gefitinib has not been clearly stated. Direct clinical data comparing the activity and tolerability of different inhibitors are still needed.

[Afatinib (BIBW 2992)]

Afatinib (BIBW 2992) is an irreversible multi-target HER receptor tyrosine kinase inhibitor developed in patients with advanced solid tumours. Several phase I studies were conducted in patients with non-small cell lung cancer (NSCLC), as a single agent or in combination. In further phase II or III studies, patients were selected based on the duration of response to first generation EGFR-TKI in previous line (supposed to have greater chance to have an activating EGFR mutation) or based directly on the EGFR activating mutation status. Here, we report and comment the main results of these studies in lung cancer patients. This drug has been approved by the Food and Drug Administration in June 2013 for the first-line treatment of patients with metastatic NSCLC whose tumours have EGFR mutation. In Europe, it has been approved in September 2013 in the same indication.

The design and discovery of water soluble 4-substituted-2,6-dimethylfuro[2,3-d]pyrimidines as multitargeted receptor tyrosine kinase inhibitors and microtubule targeting antitumor agents

The design, synthesis and biological evaluations of fourteen 4-substituted 2,6-dimethylfuro[2,3-d]pyrimidines are reported. Four compounds (11-13, 15) inhibit vascular endothelial growth factor receptor-2 (VEGFR-2), platelet-derived growth factor receptor β (PDGFR-β), and target tubulin leading to cytotoxicity. Compound 11 has nanomolar potency, comparable to sunitinib and semaxinib, against tumor cell lines overexpressing VEGFR-2 and PDGFR-β. Further, 11 binds at the colchicine site on tubulin, depolymerizes cellular microtubules and inhibits purified tubulin assembly and overcomes both βIII-tubulin and P-glycoprotein-mediated drug resistance, and initiates mitotic arrest leading to apoptosis. In vivo, its HCl salt, 21, reduced tumor size and vascularity in xenograft and allograft murine models and was superior to docetaxel and sunitinib, without overt toxicity. Thus 21 affords potential combination chemotherapy in a single agent.

Afatinib: first global approval

Afatinib, an irreversible inhibitor of the ErbB family of tyrosine kinases, is under development with Boehringer Ingelheim for the once-daily, oral treatment of cancer. Afatinib downregulates ErbB signalling by covalently binding to epidermal growth factor receptor (EGFR), human epidermal growth factor receptor (HER) 2 and HER4, irreversibly inhibiting tyrosine kinase autophosphorylation. It also inhibits transphosphorylation of HER3. Oral afatinib (Gilotrif™) has been approved in the US for the first-line treatment of patients with metastatic non-small-cell lung cancer (NSCLC) who have tumours with EGFR exon 19 deletions or exon 21 (L858R) substitution mutations as detected by a US FDA-approved test. Afatinib has also been approved in Taiwan for the first-line treatment of patients with EGFR mutation-positive NSCLC. In addition, the European Medicines Agency's Committee for Medicinal Products for Human Use has recommended the approval of afatinib (Giotrif®) for the treatment of patients with locally advanced or metastatic NSCLC with activating EGFR mutations who are EGFR tyrosine kinase inhibitor naïve. Afatinib is also under regulatory review in Canada, Japan and other Asian countries. This article summarizes the milestones in the development of afatinib, leading to this first approval in patients with metastatic NSCLC.

Preclinical and clinical development of afatinib: a focus on breast cancer and squamous cell carcinoma of the head and neck

ABSTRACT: Aberrant signaling of the ErbB family of receptors plays an integral role in the tumorigenesis of many cancer types, including head and neck squamous cell carcinoma (HNSCC) and breast cancer (BC). Significant research efforts have focused on developing new treatments that target ErbB family members, with the last decade seeing the approval of small-molecule tyrosine kinase inhibitors and monoclonal antibodies that inhibit ErbB signaling. However, treatment resistance is an ever-growing problem and, therefore, new therapies are being investigated to overcome this hurdle. Afatinib is an irreversible ErbB family blocker that has demonstrated potent anti-tumor activity in preclinical models and has displayed clinical efficacy in patients with non-small-cell lung cancer, and activity in HNSCC and BC. Here, the preclinical and clinical development of afatinib in the treatment of non-small-cell lung cancer, HNSCC and BC is described in the context of currently approved agents.