In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 31, No. 6_suppl ( 2013-02-20), p. 271-271
Abstract:
271 Background: ALT-801, a T-cell receptor/IL-2 fusion protein, activates NK and CD4 + lymphocytes to secrete IFN-gamma which re-polarizes tumor associated macrophages from M1 to M2 in various murine tumor models. CD8 + memory cells also acquire an innate immune phenotype and become expanded upon ALT-801 activation. Via this novel mechanism, ALT-801 mounted effective immune responses and maintained immunological memory against urothelial cancer in these models. Pretreatment chemotherapy eliminated myeloid-derived suppressive cells, potentiating the anti-tumor effects of ALT-801 (Wong, unpublished data). Previous clinical studies with ALT-801 (advanced malignancy; Fishman 2011 CCR 17:7765) and ALT-801 + cisplatin (melanoma; NCT01029873) showed anti-tumor activity in these settings. Methods: We evaluated co-administration of gemcitabine [G] (1000 mg/m 2 /dose, day 1 and 8) and cisplatin [C] (70 mg/m 2 /dose, day 1) with ALT-801 (escalating doses; days 3, 5, 8, 10) for three 21-day cycles, in patients with metastatic urothelial cancer. Those with at least stable disease after 3 courses could receive 4 additional weekly doses of ALT-801 alone. ALT-801 doses were planned at 0.04 to 0.12 mg/kg/dose in 5 cohorts with a 3+3 escalation design. Results: The dose-escalation is completed, with a recommended dose of ALT-801 of 0.06 mg/kg/dose. The best objective response rate (ORR, RECIST v1.1) among 5 chemo-naïve subjects was 100% (2 CR, 3 PR) and among 5 previously treated patients 60% (1 CR, 2 PR), for an overall total of 80% (3 CR, 5 PR, 1 SD, 1 PD). One of 2 patients who underwent radical cystectomy was confirmed pathologically free of tumor. Responding lesions included bulky and extensive liver and pulmonary metastases, and adenopathy. ALT-801 at the 0.06 mg/kg/dose level in this combination was adequately-tolerated. Grade 3/4 toxicities including neutropenia, thrombocytopenia and lymphopenia, appear consistent with known G, C, and ALT-801 effects. Conclusions: ALT-801 is a novel and potentially active immunotherapy for urothelial cancer. More patients are in treatment on the open phase 2 expansion portion of the study (NCT01326871), and updated interim results are anticipated (CA097550). Clinical trial information: NCT01326871.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2013.31.6_suppl.271
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2013
detail.hit.zdb_id:
2005181-5
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