Tubes of differing cellular architecture connect into networks. In the Drosophila tracheal system, two tube types connect within single cells (terminal cells); however, the genes that mediate this interconnection are unknown. Here we characterize two genes that are essential for this process: lotus, required for maintaining a connection between the tubes, and wheezy, required to prevent local tube dilation. We find that lotus encodes N-ethylmaleimide Sensitive Factor 2 (NSF2), while wheezy encodes Germinal Center Kinase III (GCKIII). GCKIIIs are effectors of Cerebral Cavernous Malformation 3 (CCM3), a protein mutated in vascular disease. Depletion of CCM3 by RNA interference phenocopies wheezy; thus, CCM3 and GCKIII, which prevent capillary dilation in humans, prevent tube dilation in Drosophila trachea. Ectopic junctional and apical proteins are present in wheezy terminal cells, and we show that tube dilation is suppressed by reduction of NSF2, of the apical determinant Crumbs, or of septate junction protein Varicose.

5FU does not substantially affect the metabolism of CPT-11 to its active metabolite, SN-38. The combination of CPT-11125 mg/m2, 5FU 500 mg/m2, and leucovorin 20 mg/m2 is feasible and tolerable on this schedule.

there were no DLTs, but 3 of 11 patients came off study early due to gemcitabine-attributed adverse events (AE). Minimal AEs were attributed to p53MVA vaccination. Immunologic and clinical response: enhanced recognition of p53 peptides was detectable after immunization in both the CD4 and CD8 T-cell compartments in 5 of 11 and 6 of 11 patients, respectively. Changes in peripheral T regulatory cells (Tregs) and myeloid-derived suppressor cells (MDSC) did not correlate significantly with vaccine response or progression-free survival (PFS). Patients with the greatest expansion of p53-reactive T cells had significantly longer PFS than patients with lower p53-reactivity after therapy. Tumor shrinkage or disease stabilization occurred in 4 patients. p53MVA was well tolerated, but gemcitabine without steroid pretreatment was intolerable in some patients. However, elevated p53-reactive CD4 and CD8 T-cell responses after therapy correlated with longer PFS. Therefore, if responses to p53MVA can be enhanced with alternative agents, superior clinical responses may be achievable. .

The administration of cisplatin and irinotecan on this weekly schedule provides a practical and well-tolerated regimen that has the potential to maximize any clinical synergy between the two agents. Evidence of substantial clinical activity was seen in this phase I study.

5542 Background: Mirvetuximab soravtansine (MIRV) is an ADC comprising a FRα-binding antibody, cleavable linker, and the maytansinoid DM4, a potent tubulin-targeting agent. MIRV has promising single agent activity in FRα-positive medium/high expression epithelial ovarian cancer (EOC), at 6 mg/kg, based on adjusted ideal body weight (AIBW) IV every (q) 21 days. This study evaluated MIRV and G in recurrent EOC, endometrial and triple negative breast cancer. The recommended phase 2 dose (RP2D) was established at MIRV 6 mg/kg AIBW IV, day 1 and G 800 mg/m2 IV, d1, 8 q21 days (J Clin Oncol 37, 2019, Abs. #3009). Here we report the results from the EOC cohort. Methods: Patients (pts) with FRα-positive platinum resistant EOC with ≤4 prior chemotherapy (CT) regimens, were eligible. FRα positivity was initially defined as ≥ 25% of cells with PS2+ staining intensity (low to high FRα expression) and was subsequently revised to require medium/high FRα expression (≥50%/ ≥75% of cells with PS2+ staining intensity). Results: From 10/2017 to 12/2020, 113 EOC pts underwent FRα screening, with 74 FRα-positive results. Thirty total EOC pts (with median 3 prior lines of therapy) were treated; 8 pts during dose escalation and 22 EOC pts at the RP2D (all evaluable for response). Fifteen (50%) pts had high FRα, 10 pts (33%) medium FRα, and 5 pts (17%) low FRα expression. Eleven (36%) of the 30 EOC pts achieved a partial response (PR), 15 pts (50%) had SD and 4 pts (13%) progressed. Among the 11 responders, 5 pts had high FRα, 4 pts medium FRα and 2 pts low FRα expression. Non-heme clinically significant adverse events (AEs) included: G2 sensory neuropathy (4 pts) G3 diarrhea (3 pts), G3 fatigue (2 pts), G3 pneumonitis (2 pts), and 1 pt with G5 respiratory failure (secondary to pneumonia but drug-induced pneumonitis could not be ruled out). Conclusions: MIRV in combination with G has promising clinical activity in late line platinum resistant FRα-positive EOC, with best responses observed in high FRα expression. The regimen is well tolerated with expected AEs based on the known toxicities of each agent. This study was approved and funded by the National Comprehensive Cancer Network (NCCN) Oncology Research Program from general research support provided by ImmunoGen Corp and Cancer Center Support Grant P30CA033572. Clinical trial information: NCT02996825.