Genomic Analysis of Tumors from Patients with Glioblastoma with Long-Term Response to Afatinib.

Glioblastoma is an aggressive form of central nervous system tumor. Recurrence rates following primary therapy are high, and few second-line treatment options provide durable clinical benefit. Aberrations of the epidermal growth factor receptor (EGFR) gene are observed in up to 57% of glioblastoma cases and EGFR overexpression has been identified in approximately 60% of primary glioblastomas. In preclinical studies, afatinib, a second-generation ErbB blocker, inhibited cell proliferation in cells harboring mutations commonly found in glioblastoma. In two previous Phase I/II studies of afatinib plus temozolomide in patients with glioblastoma, limited efficacy was observed; however, there was notable benefit in patients with the EGFR variant III (EGFRvIII) mutation, EGFR amplification, and those with loss of phosphatase and tensin homolog (PTEN). This case series report details treatment histories of three long-term responders from these trials. Next-generation sequencing of tumor samples identified alterations in a number of cancer-related genes, including mutations in, and amplification of, EGFR. Tumor samples from all three patients shared favorable prognostic factors, eg O6-methylguanine-DNA methyl-transferase (MGMT) gene promoter methylation; however, negative prognostic factors were also observed, suggesting that these shared genetic features did not completely account for the favorable responses. The genetic profile of the tumor from Patient 1 showed clear differences from the other two tumors: lack of involvement of EGFR aberrations but with a mutation occurring in PTPN11. Preclinical studies showed that single-agent afatinib and temozolomide both separately inhibit the growth of tumors with a C-terminal EGFR truncation, thus providing further rationale for combining these two agents in the treatment of glioblastomas harboring EGFR aberrations. These findings suggest that afatinib may provide treatment benefit in patients with glioblastomas that harbor ErbB family aberrations and, potentially, other genetic aberrations. Further studies are needed to establish which patients with newly diagnosed/recurrent glioblastomas may potentially benefit from treatment with afatinib.

Afatinib alone and in combination with vinorelbine or paclitaxel, in patients with HER2-positive breast cancer who failed or progressed on prior trastuzumab and/or lapatinib (LUX-Breast 2): an open-label, multicenter, phase II trial.

PURPOSE: Resistance to HER2 (ErbB2)-targeted therapy may be mediated by other members of the ErbB family. We investigated the efficacy and safety of the irreversible ErbB family blocker, afatinib, alone as first-line therapy in the advanced setting and in combination with vinorelbine or paclitaxel for those who progressed on afatinib monotherapy, in female patients with metastatic breast cancer who had failed or progressed on prior HER2-targeted therapy in the early disease setting. METHODS: In this phase II, single-arm, two-part study (ClinicalTrials.gov: NCT01271725), patients in part A received afatinib 40 mg/day in 21-day cycles until disease progression or intolerable adverse events (AEs). Patients with progressive disease could then receive afatinib plus weekly vinorelbine 25 mg/m2 or paclitaxel 80 mg/m2 until disease progression or intolerable AEs (part B). The primary endpoint was confirmed objective response rate (RECIST v1.1). RESULTS: Eighty-seven patients were enrolled and 74 were treated in part A (median age: 51 years [range 27-76]; 31 [42%] estrogen receptor-positive, 26 [35%] progesterone receptor-positive). Of these, 39 (53%) patients went on to receive afatinib plus vinorelbine (13 patients) or paclitaxel (26 patients) in part B. Thirteen (18%) and 12 (31%) patients achieved an objective response in parts A and B, respectively. The most common treatment-related AEs with afatinib monotherapy (any/grade ≥ 3) were diarrhea (68%/8%) and rash (49%/4%). Combination therapy was generally well tolerated, with no additive toxicity observed. CONCLUSION: Afatinib treatment, alone or in combination with vinorelbine or paclitaxel, was associated with objective responses in ≥ 18% of patients with metastatic breast cancer for whom prior HER2-targeted therapy has failed. Treatment-related AEs were generally manageable, with few grade ≥ 3 AEs reported. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01271725, registered 1 July 2011.

Afatinib and radiotherapy, with or without temozolomide, in patients with newly diagnosed glioblastoma: results of a phase I trial.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in adults. Amplification or overexpression of the epidermal growth factor receptor gene, part of the ErbB family, occur in approximately 40% and 60% of patients with GBM, respectively. We present data from a dose-finding study of the ErbB inhibitor afatinib in combination with radiotherapy (RT), with or without temozolomide (TMZ), in patients with GBM. METHODS: This was a phase I, open-label, 3 + 3 dose-escalation trial in patients with newly-diagnosed, histologically-confirmed grade 4 malignant glioma and proven O6-methylguanine-DNA methyltransferase gene promoter methylation status. The primary endpoint was the maximum tolerated dose (MTD) of continuous daily afatinib when given in combination with RT, with (regimen M) or without (regimen U) concomitant TMZ treatment. RESULTS: Fifty-five patients were enrolled; 36 received ≥ 1 dose of trial medication (regimen M, n = 20, regimen U, n = 16). Afatinib was discontinued by all patients during the study. Reasons for afatinib discontinuation (regimen M/U) included disease progression (45%/50%), dose-limiting toxicity (10%/0%), and other adverse events (AEs; 35%/38%). The most frequently reported AEs with either regimen were diarrhea and rash, with no new safety signals identified. The MTD was determined as afatinib 30 mg in combination with daily TMZ and RT, and afatinib 40 mg in combination with RT alone. CONCLUSIONS: This study identified the MTD for afatinib in combination with RT, with and without TMZ, in patients with GBM. Further studies of afatinib in patients with GBM are warranted and should be based on appropriate biomarker-based preselection. TRIAL REGISTRATION: NCT00977431 (first posted September 15, 2009).

A phase I study to assess afatinib in combination with carboplatin or with carboplatin plus paclitaxel in patients with advanced solid tumors.

PURPOSE: Afatinib, an irreversible ErbB family blocker, has demonstrated preclinical antitumor activity with chemotherapy. METHODS: As part of a phase I trial in patients with advanced solid tumors (NCT00809133; 3 + 3 dose-escalation design), we determined the maximum tolerated dose (MTD) of afatinib with carboplatin (A/C) or with carboplatin plus paclitaxel (A/C/P). Starting doses: afatinib 20 mg/day, carboplatin AUC6 (A/C) with paclitaxel 175 mg/m2 (A/C/P) (chemotherapy: Day 1 of 21-day cycles). The primary objective was to determine the MTDs; safety, pharmacokinetics and antitumor activity were also evaluated. RESULTS: Thirty-eight patients received A/C (n = 12) or A/C/P (n = 26). No dose-limiting toxicities (DLTs) were reported with A(20 mg)/C(AUC6). One patient experienced DLT in the A(40 mg)/C(AUC6) cohort (grade 3 acneiform rash); A(40 mg)/C(AUC6) was determined as the recommended phase II dose (RP2D) for A/C. Two patients each had DLTs with A(20 mg/day)/C(AUC6)/P(175 mg/m2): fatigue, infection, diarrhea, small intestine hemorrhage, dehydration, renal impairment, neutropenic sepsis (n = 1), mucositis (n = 1); A(40 mg)/C(AUC5)/P(175 mg/m2): febrile neutropenia (n = 1), mucositis, fatigue (n = 1); and A(30 mg)/C(AUC5)/P(175 mg/m2): stomatitis (n = 1), mucositis (n = 1). No DLT was observed with A(20 mg)/C(AUC5)/P(175 mg/m2), determined as the RP2D for A/C/P. The most frequent drug-related adverse events were (A/C; A/C/P): rash (75%; 73%), fatigue (67%; 69%), and diarrhea (58%; 88%). Drug plasma concentrations were similar between cycles, suggesting no drug-drug interactions. Objective response rates in these heavily pretreated patients were A/C, 3/12 (25%); A/C/P, 5/26 (19%). CONCLUSIONS: Afatinib 40 mg/day (approved monotherapy dose) with carboplatin AUC6, and afatinib 20 mg/day with carboplatin AUC5 and paclitaxel 175 mg/m2 demonstrated manageable safety and antitumor activity. Afatinib > 20 mg/day in the triple combination was not well tolerated.

A phase I study of afatinib combined with paclitaxel and bevacizumab in patients with advanced solid tumors.

PURPOSE: The combination of afatinib, an irreversible ErbB family blocker, with paclitaxel and bevacizumab was assessed in patients with advanced solid tumors. METHODS: This phase I study used a 3 + 3 design to determine the maximum tolerated dose (MTD) of afatinib combined with paclitaxel and bevacizumab. Safety, pharmacokinetics, and anti-tumor activity were also assessed. The starting dose was oral afatinib 40 mg once daily plus intravenous paclitaxel (fixed dose 80 mg/m2, Days 1, 8, and 15 of a 4-week cycle) and intravenous bevacizumab 5 mg/kg every 2 weeks. RESULTS: Twenty-nine patients were enroled. The afatinib dose was de-escalated to 30 mg and then 20 mg after 2/6 and 2/5 evaluable patients developed dose-limiting toxicities at 40 and 30 mg, respectively, when combined with paclitaxel and bevacizumab 5 mg/kg. The bevacizumab dose was subsequently escalated to 10 mg/kg, and MTD was defined as afatinib 20 mg plus paclitaxel 80 mg/m2 and bevacizumab 10 mg/kg. Frequent (any grade) treatment-related adverse events (AEs) included diarrhea (83%), rash/acne (83%), fatigue (79%), mucosal inflammation (59%), and nausea (59%). Based on overall safety, bevacizumab was amended to 7.5 mg/kg for the recommended phase II dose. Pharmacokinetic analyses suggested no relevant drug-drug interactions. Three (10%) confirmed partial responses were observed; 15 (52%) patients had stable disease. CONCLUSIONS: The recommended phase II dose schedule was afatinib 20 mg/day with paclitaxel 80 mg/m2 (Days 1, 8, and 15 every 4 weeks) and bevacizumab 7.5 mg/kg every 2 weeks. At this dose schedule, AEs were manageable, and anti-tumor activity was observed.