Tumor protein p53 mutation in archived tumor samples from a 12-year survivor of stage 4 pancreatic ductal adenocarcinoma may predict long-term survival with DeltaRex-G: A case report and literature review.

Journal Article (Journal Article)

DeltaRex-G is a replication-incompetent amphotropic murine leukemia virus-based retroviral vector that displays a collagen-matrix-targeting decapeptide on its surface envelope protein, gp70, and encodes a cytocidal 'dominant negative', i.e. a truncated construct of the executive cyclin G1 (CCNG1 ) oncogene. DeltaRex-G inhibits the CCNG1 function of promoting cell competence and survival through the commanding CCNG1 /cyclin-dependent kinase (CDK)/Myc/mouse double minute 2 homolog (Mdm2)/p53 axis. In 2009, DeltaRex-G was granted Fast Track designation from the US Food and Drug Administration for the treatment of pancreatic cancer. In 2019, the results of a phase 1/2 study that used DeltaRex-G as monotherapy for stage 4 chemotherapy-resistant pancreatic ductal adenocarcinoma (PDAC) were published. A unique participant of the aforementioned phase 1/2 study is now an 84-year-old Caucasian woman with chemoresistant PDAC who was treated with DeltaRex-G, 3x1011 colony forming units (cfu)/dose, 3 times/week for 4 weeks with a 2-week rest period, for 1.5 years. During the treatment period, the patient's tumors in the liver, lymph node and peritoneum exhibited progressive decreases in size, which were accompanied by a reduction and normalization of serum carbohydrate antigen 19-9 levels, and the patient achieved complete remission after 8 months of DeltaRex-G therapy with minimal side effects (grade 2 fatigue). Henceforth, the patient has been in remission for 12 years with no evidence of disease, no late therapy-related adverse events, and no further cancer therapy following DeltaRex-G treatment. The present study reports a mutation of tumor protein p53 (TP53) (G199V ) found retrospectively in the patient's archived tumor samples. TP53 is a well-characterized tumor suppressor gene, and a critical regulatory component of the executive CCNG1 /CDK/Myc/Mdm2/p53 axis, which regulates proliferative cell competence, DNA fidelity and survival. Studies are underway to determine whether TP53 mutations in pancreatic cancer can help identify a subset of patients with advanced metastatic cancer with an otherwise poor prognosis who would respond favorably to DeltaRex-G, which would broaden the treatment options for patients with otherwise lethal PDAC.

Full Text

Duke Authors

Cited Authors

  • Morse, MA; Chawla, SP; Wong, TZ; Bruckner, HW; Hall, FL; Gordon, EM

Published Date

  • September 2021

Published In

Volume / Issue

  • 15 / 3

Start / End Page

  • 186 -

PubMed ID

  • 34277005

Pubmed Central ID

  • PMC8278409

Electronic International Standard Serial Number (EISSN)

  • 2049-9469

International Standard Serial Number (ISSN)

  • 2049-9450

Digital Object Identifier (DOI)

  • 10.3892/mco.2021.2348

Language

  • eng