These sort of beg the question... why caution?
:-)
Just catching up to the stock, but know some of the programs. Thanks for the tickler. Hope I didn't run through an embargo. Looked and didn't see one.
Abstract / IMMUNOTHERAPY/VACCINE THERAPY (CLINICAL AND/OR LABORATORY RESEARCH)
IT-30
ReACT: A PHASE II STUDY OF RINDOPEPIMUT VACCINE (CDX-110) PLUS BEVACIZUMAB IN RELAPSED GLIOBLASTOMA
BACKGROUND: EGFRvIII, a constitutively active tumorigenic EGFR deletion mutation, is linked to poor long-term survival. The investigational vaccine rindopepimut consists of the unique EGFRvIII peptide sequence conjugated to keyhole limpet hemocyanin (KLH), delivered intradermally with GM-CSF. Three phase II studies of rindopepimut in newly diagnosed, resected, EGFRvIII+ glioblastoma have shown encouraging PFS and OS. Bevacizumab (BV), an agent with activity in glioblastoma, may augment EGFRvIII-specific immune response and antitumor activity through inhibition of VEGF and its immunosuppressive properties. METHODS: “ReACT” is a Phase II study of rindopepimut plus BV in patients with 1st or 2nd relapse of EGFRvIII+ glioblastoma. BV-naïve pts (Group 1; n = 70) are randomized 1:1 to BV plus double-blinded injection of either rindopepimut or control (KLH). BV-refractory patients (progression within 2 months of BV; Group 2/2C, n = 98) receive BV plus open-label rindopepimut. RESULTS: 234/700 (33%) screened patients are EGFRvIII+. 115 patients (Group 1 = 72, Group 2/2C = 43) are enrolled. Primary toxicity is Grade 1-2 injection site reaction. In group 1, for rindopepimut + BV vs. KLH + BV, objective response rate (ORR; investigator-assessed, RANO criteria) is 23% (6/26) vs 12% (3/25) [35% vs. 20% including responses observed at a single time point (“unconfirmed”)]. In Group 2/2C (evaluable n = 30), one unconfirmed PR and one sustained PR (patient continues treatment at 15 months) occurred. Two additional patients had pre-study progression >2 months after BV; one maintained a CR for 11.1 months (peak anti-EGFRvIII titer = 1:3,276,800), while the second experienced an unconfirmed CR. Median peak rindopepimut-induced anti-EGFRvIII humoral response is 1:25,600 [range <1:100-1:6,553,600]). Rapid titer generation was associated with prolonged OS (Group 2: p = 0.01). CONCLUSIONS: Rindopepimut + BV has induced potent EGFRvIII-specific immune response and tumor regression in immunosuppressed recurrent glioblastoma patients naive or refractory to BV. Full response, PFS and OS data are expected to further define the potential clinical benefit of the combination in relapsed glioblastoma.
Abstract / IMMUNOTHERAPY/VACCINE THERAPY (CLINICAL AND/OR LABORATORY RESEARCH)
IT-28
VACCINATION AGAINST EPIDERMAL GROWTH FACTOR RECEPTOR VARIANT III IN GLIOBLASTOMA: THE RINDOPEPIMUT COMPASSIONATE USE EXPERIENCE
The tumor-specific epidermal growth factor receptor variant III mutation (EGFRvIII) is widely expressed in glioblastoma and thus represents an attractive target for immunotherapeutic approaches. The investigational vaccine rindopepimut is an EGFRvIII peptide sequence conjugated to keyhole limpet hemocyanin and is administered intradermally with GM-CSF. Previous single-arm studies of rindopepimut in newly diagnosed, resected, EGFRvIII+ glioblastoma have shown encouraging PFS and OS. This compassionate use program provided rindopepimut to 61 EGFRvIII+ glioblastoma patients who were ineligible for ongoing clinical trials. Data are currently available on 42 patients, 12 (29%) with newly diagnosed glioblastoma (resected or inoperable) and 30 (71%) with recurrent disease. MGMT methylation was seen in 9/17, while all tested patients were negative for IDH1 (12/12) and IDH2 (7/7). Median age was 53 years (15-70) and median time from diagnosis was 14.5 months (2.7-58.7). Rindopepimut, administered in combination with temozolomide (57%), bevacizumab (57%), and/or other (17%), was well tolerated, with frequent mild injection site reactions and one potentially treatment-related, serious event of cerebral edema. Median peak rindopepimut-induced anti-EGFRvIII titer was 1:1,200 (<1:100-1:6,553,600). Median treatment duration is currently 3.7 (0.03-60.1) months. Tumor response (>50% shrinkage in measurable disease) was observed in six patients receiving rindopepimut with other agents. One inoperable glioblastoma patient experienced a CR during treatment with rindopepimut, erlotinib, temozolomide, and bevacizumab, and has continued rindopepimut for >5 years without significant toxicity or disease recurrence. Biopsy at recurrence showed EGFRvIII was eliminated in a patient who received rindopepimut and temozolomide for ~9 months. In patients with newly diagnosed and recurrent glioblastoma, respectively, median PFS was 9.1 and 2.5 months, and median OS was 15.7 and 8.7 months from first vaccination. In conclusion, rindopepimut in combination with various anticancer therapies resulted in robust anti-EGFRvIII humoral response with minimal toxicity. PFS and OS appear promising in this heterogeneous, poor prognosis population. |
