SEOUL, South Korea, Sept. 4 Exelixis, Inc.(Nasdaq: EXEL) today reported interim data from an ongoing phase 2 trialevaluating XL647 as first-line therapy for patients with non-small cell lungcancer (NSCLC). This open-label phase 2 trial is ongoing in previouslyuntreated patients with stage IIIB or IV NSCLC who have adenocarcinomahistology and meet one of the following three criteria: Asian descent, femalegender, or no or minimal smoking history. XL647 is administered orally, at adose of 350 mg on Days 1-5 of repeated 14-day cycles.
To date, over 60% of evaluable patients in the phase 2 study have hadpartial responses (PR) or stable disease (SD) as their best response.Importantly, responses have been observed in patients with and withoutactivating mutations in the epidermal growth factor receptor (EGFR), a targetof XL647. Activating mutations in EGFR have been associated with improvedsensitivity to other EGFR inhibitors. Dr. Shirish Gadgeel of Karmanos CancerInstitute at Wayne State University presented the data today in a poster(Abstract P3-136) at the 12th International Association for the Study of LungCancer World Conference on Lung Cancer, which is being held in Seoul, SouthKorea.
"The data reported today demonstrate that XL647 has potential utility inpatient populations with both mutated and wild-type EGFR," said Dr. ShirishGadgeel of Karmanos Cancer Institute at Wayne State University. "Importantly,the data highlight that patients to date appear to have milder EGFR-relatedside-effects -- rash and diarrhea -- than previously described with other EGFRinhibitors while retaining potent anti-tumor activity with durable responsesand stable disease. Although these are early results, they provide acompelling rationale for expediting the full development of XL647 in non-smallcell lung cancer."
"These data suggest that XL647 has the potential for utility in patientswith NSCLC who have an activating EGFR mutation and those with wild-typeEGFRs. We believe these data support an aggressive clinical developmentstrategy in first, second and third-line treatment as both a single agent andin combination with other therapies," said George A. Scangos, Ph.D., presidentand chief executive officer of Exelixis. "Moreover, new data from an ongoingphase 1 trial of XL647 suggest that daily dosing results in higher drugconcentrations than those observed to date in this phase 2 study withintermittent dosing. We expect to complete this evaluation of both daily andintermittent dosing schedules soon in order to select the optimal regimen anddose for the late-stage development of XL647."
The most frequently reported treatment-related adverse events (AEs) wereGrade 1 and 2 diarrhea and fatigue, and Grade 1 nausea and rash. Six patientshave had a maximum Grade 1 QTc interval prolongation, and 7 patients a maximumGrade 2; the increases were clinically asymptomatic and not associated withAEs or dose reduction or delay. One patient who experienced an event ofasymptomatic Grade 3 QTc interval prolongation had ineligible baseline QTcvalues (Grade 2) and was withdrawn from the study. A total of 16 serious AEswere reported in 8 patients. 5 events in 4 patients were considered possiblyor probably related to study drug: Grade 3 GI hemorrhage and duodenal ulcer in1 patient, and Grade 3 pneumonia, Grade 4 pulmonary embolism, and Grade 2haemoptysis.
XL647 is a potent inhibitor of receptor tyrosine kinases (RTKs) that areimplicated in driving tumor proliferation and vascularization (blood vesselformation). XL647 inhibits EGFR, HER2 and VEGFR2. The compound has beenoptimized for high potency and oral bioavailability (using in vivo systems),demonstrates excellent activity in target-specific cellular functional assaysand has shown sustained inhibition of target RTKs preclinically in vivofollowing a single oral dose. Two phase 2 trials i