Immunohistochemical Evaluation of CON6D/B5: A New CD30 Monoclonal Antibody

A phase 2, open-label study of brentuximab vedotin in patients with CD30-expressing solid tumors

Purpose Brentuximab vedotin (BV) is an anti-CD30 antibody-drug conjugate used in the treatment of several types of lymphomas. Expression of the target antigen has also been reported on a variety of malignant tumors of nonlymphoid origin. This phase 2, open-label study evaluated the safety and antitumor activity of BV in patients with CD30-expressing nonlymphomatous malignancies. Methods Patients were dosed with 1.8 or 2.4 mg/kg BV once every three weeks. Antitumor activity was assessed at Cycles 2, 4, and every 4 cycles thereafter. Patients with stable disease or better were eligible to continue treatment until disease progression, unacceptable toxicity, or study closure. Results Of the 2693 patients screened, 3.8% had solid tumors with CD30 expression and 63 eligible patients with solid tumors enrolled in this study. The most common CD30 positive solid tumors were testicular cancer and mesothelioma. Both subtypes had more than one patient with an objective response. The median duration of BV exposure was 6.1 weeks. The disease control rate, defined as achieving stable disease or better at any point during the study, was 55%. The objective response rate was 11%, with a median duration of response of 2.92 months. The most common adverse events reported were fatigue (57%), nausea (33%), and decreased appetite (32%). Conclusion The safety profile of BV in patients with solid tumors was similar to the known safety profile of BV. In solid tumors, BV had modest activity as a single agent, which was similar to other second-line treatments already available to patients.

Use of the Total Cancer Care System to Enrich Screening for CD30-Positive Solid Tumors for Patient Enrollment Into a Brentuximab Vedotin Clinical Trial: A Pilot Study to Evaluate Feasibility

Background

One approach to identify patients who meet specific eligibility criteria for target-based clinical trials is to use patient and tumor registries to prescreen patient populations.

Objective

Here we demonstrate that the Total Cancer Care (TCC) Protocol, an ongoing, observational study, may provide a solution for rapidly identifying patients with CD30-positive tumors eligible for CD30-targeted therapies such as brentuximab vedotin.

Methods

The TCC patient gene expression profiling database was retrospectively screened for CD30 gene expression determined using HuRSTA-2a520709 Affymetrix arrays (GPL15048). Banked tumor tissue samples were used to determine CD30 protein expression by semiquantitative immunohistochemistry. Statistical comparisons of Z- and H-scores were performed using R statistical software (The R Foundation), and the predictive value, accuracy, sensitivity, and specificity of CD30 gene expression versus protein expression was estimated.

Results

As of March 2015, 120,887 patients have consented to the institutional review board–approved TCC Protocol. A total of 39,157 fresh frozen tumor specimens have been collected, from which over 14,000 samples have gene expression data available. CD30 RNA was expressed in a number of solid tumors; the highest median CD30 RNA expression was observed in primary tumors from lymph node, soft tissue (many sarcomas), lung, skin, and esophagus (median Z-scores 1.011, 0.399, 0.202, 0.152, and 1.011, respectively). High level CD30 gene expression significantly enriches for CD30-positive protein expression in breast, lung, skin, and ovarian cancer; accuracy ranged from 72% to 79%, sensitivity from 75% to 100%, specificity from 70% to 76%, positive predictive value from 20% to 40%, and negative predictive value from 95% to 100%.

Conclusions

The TCC gene expression profiling database guided tissue selection that enriched for CD30 protein expression in a number of solid tumor types. Such an approach may improve screening efficiency for enrolling patients into biomarker-based clinical trials.

Nucleic Acid Aptamers as Potential Therapeutic and Diagnostic Agents for Lymphoma

Lymphomas are cancers that arise from white blood cells and usually present as solid tumors. Treatment of lymphoma often involves chemotherapy, and can also include radiotherapy and/or bone marrow transplantation. There is an un-questioned need for more effective therapies and diagnostic tool for lymphoma. Aptamers are single stranded DNA or RNA oligonucleotides whose three-dimensional structures are dictated by their sequences. The immense diversity in function and structure of nucleic acids enable numerous aptamers to be generated through an iterative in vitro selection technique known as Systematic Evolution of Ligands by EXponential enrichment (SELEX). Aptamers have several biochemical properties that make them attractive tools for use as potential diagnostic and pharmacologic agents. Isolated aptamers may directly inhibit the function of target proteins, or they can also be formulated for use as delivery agents for other therapeutic or imaging cargoes. More complex aptamer identification methods, using whole cancer cells (Cell-SELEX), may identify novel targets and aptamers to affect them. This review focuses on recent advances in the use of nucleic acid aptamers as diagnostic and therapeutic agents and as targeted delivery carriers that are relevant to lymphoma. Some representative examples are also discussed.