Idiotype Vaccination of Untreated Indolent B-Cell Lymphoma: Durable Objective Remissions and Association of Superior Outcome with Cellular Immune Responses
| Autor: | Andrea Hafkemeyer, Marcus Duehren-von Minden, Cristina Bertinetti-Lapatki, Marcelo A. Navarrete, Hendrik Veelken, Kristina Heining-Mikesch |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Blood. 112:235-235 |
| ISSN: | 1528-0020 0006-4971 |
| Popis: | Idiotype vaccination refers to active immunization of B-cell lymphoma (B-NHL) patients with the clonal immunoglobulin (Ig) expressed by the tumor cells. After systemic cytoreductive therapy, idiotype vaccination has been shown to induce specific cellular and humoral immune responses; and humoral responses in particular are associated with prolonged remission and encouraging survival rates. Conventional idiotype vaccines are composed of the entire lymphoma-derived Ig coupled to the immunogenic carrier KLH and are administered subcutaneously with adjuvant. We have developed a idiotype production strategy based on bacterial expression of the lymphoma-derived idiotype as a recombinant Fab fragment (Bertinetti et al., EJH 2006). Intradermal administration of this antigen with lipid-based adjuvant and subcutaneous coadministration of GM-CSF had excellent immunogenicity in a phase I trial of advanced, heavily pretreated B-NHL patients (Bertinetti et al., Cancer Research 2006). In a subsequent phase II trial, 20 patients with untreated indolent B-NHL (14 follicular [FL], 3 nodal marginal zone [nMZL], 3 mantle cell [MCL]) and without immediate need for cytoreduction received at least 6 monthly idiotype vaccinations. No grade IV toxicities were seen, and the sole case of grade III toxicity, generalized erythema, did not preclude completion of the vaccination schedule. Prior to vaccination, 5/19 patients (26%) had decreased CD4+ and 6/19 patients (31%) low CD8+ T cells counts. Furthermore, 10/12 anti-HbS-negative patients (83%) failed to mount a detectable immune response to a conventional hepatitis B vaccine administered concomitantly to idiotype vaccination. Despite this functional immunodeficiency, 12/18 analyzed patients (66%) developed a cellular immune response to idiotype as detected by enumeration of IFNgamma-secreting cells by DC-ELISpot. The ELISpot protocol was validated by blinded interlaboratory testing (www.cimt.de). The frequency of idiotype-responding T cells increased from the 2nd to the 6th vaccination and could be effectively boostered by maintenance immunization in 3-monthly intervals. In vitro stimulation of PBMC from responding patients with idiotype induced specific proliferation of CD4+ T-cells and a shift towards a Th1 response in post-vaccination samples. In addition, 8/18 analyzed patients (44%) developed anti-idiotype IgG or IgM antibodies as assessed by ELISA, and the combined immune response rate was 85%. After a median follow-up of 34 months, 8 patients (40%) are progression-free, and 10 (50%) did not require cytoreductive therapy. Cellular immune responses were associated with superior PFS (p |
| Databáze: | OpenAIRE |
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