Almac Diagnostics announced this week it is collaborating with Pfizer and the PETACC3 Translational Research Working Party to identify molecular subtypes in colorectal cancer and to identify new drug targets in treatment-resistant patients.
In the study the researchers will use Almac's Colorectal Cancer DSA platform to perform gene expression profiling of formalin-fixed paraffin-embedded samples from the Pan-European Trials in Adjuvant Colon Cancer (PETACC 3) trial.
The PETACC 3 study is an international randomized, prospective trial that tried to show that adding irinotecan to combination chemotherapy regimens increased efficacy in patients with stage II/III colon cancer.
That study, published in the Journal of Clinical Oncology in 2005, found that while irinotecan increases the efficacy of chemo regimen LV5FU2 in stage III colon cancer patients, it failed to reach statistical significance at a median follow-up of 32 months with an acceptable safety profile. "Irinotecan increases significantly the efficacy of LV5FU2 in the pooled population of stage II/III patients," concluded Van Cutsem et al.
Pfizer, which manufactures irinotecan under the brand name Camptosar, will use the resulting research and data from the Almac collaboration for drug development purposes, a spokesperson for Almac told Pharmacogenomics Reporter this week.
"As understanding grows of the heterogeneity of cancer, it is becoming increasingly clear that molecular subtypes are important both in patients’ prognosis and in predicting their response to chemotherapy," Paul Harkin, Almac managing director, said in a statement this week. "This has already been shown in breast cancer, and the study to be led by Almac, Pfizer, and PTRW aims to examine this in colorectal cancer."
Irinotecan is mainly used as a second-line chemotherapy treatment for colorectal cancer, the third most common form of cancer in the US. In the spring of 2005, the FDA altered the drug’s label to recommend oncologists to screen patients for a variation of the UGT1A1 gene, called UGT1A1*28, which could make them more susceptible to adverse events linked to the drug. One such adverse event is neutropenia, a blood disorder that limits the body’s production of white blood cells, hobbling immunity.
In updating irinotecan's label, the FDA recommended a "reduction in the starting dose" for patients known to be homozygous for the UGT1A1*28 allele. The new label did not include specific dosing information, or suggest a specific diagnostic test for the allele [see PGx Reporter 08-29-2007].
Northern Ireland-based Almac provides translational genomic-based solutions for pharma, biotech, and academia. The company specializes in working with fresh and FFPE tissue for the generation of predictive and prognostic tests, drug development, target identification, and companion diagnostics.
Almac's Disease-Specific Array, or DSA, is based on the Affymetrix microarray platform. "Array content has been generated through a process of sequencing, gene expression profiling, and mining of public databases, followed by extensive bioinformatics analysis to create and annotate the unique, comprehensive coverage of the colorectal cancer transcriptome," the company said in a statement.