Dose de-escalation to adalimumab 40 mg every 3 weeks in patients with Crohn's disease - a nested case-control study.

BACKGROUND: Data on dose de-escalation in patients with Crohn's disease (CD) are limited. AIM: To evaluate outcomes of dose de-escalation from adalimumab (ADM) every other week (EOW) to every three weeks (ETW). METHODS: We selected patients with CD receiving maintenance therapy with ADM 40 mg ETW with serum levels (SL) available before and after dose de-escalation. Sex- and age-matched controls continuing ADM 40 mg EOW were identified. Patient reported outcome, C-reactive protein (CRP) and serum albumin were collected. RESULTS: Out of 898 patients, we identified 40 (11 male, median 37 years) who de-escalated to ADM 40 mg ETW for ADM-related adverse events (AE, n = 1), ADM SL >7 µg/mL (n = 8), or both (n = 31). Compared to controls, ADM SL dropped significantly within 4 months, without associated clinical or biochemical changes. In 53% of patients, dose de-escalation was associated with disappearance of AE (8/16 skin manifestation, 3/6 arthralgia, 5/7 frequent infectious episodes). During a median follow-up of 24 months, 65% of patients maintained clinical response, but 35% needed dose escalation back to ADM 40 mg EOW because of clinical relapse (n = 8), ADM SL <4 µg/mL (n = 2), or both (n = 4). CRP <3.5 mg/L at dose de-escalation was independently associated with dose escalation-free survival [odds ratio 6.28 (95% CI 1.83-21.59), P = 0.004]. We could not define a minimal ADM SL to consider or maintain dose de-escalation. CONCLUSIONS: Overall, 65% of patients who de-escalated to adalimumab 40 mg every 3 weeks remained in clinical remission for a median of 24 months. In 53% of patients, adalimumab-related adverse events disappeared after dose de-escalation. Regardless of adalimumab SL, disease remission should be assessed objectively prior to dose de-escalation.

Retronectin-assisted retroviral transduction of primary human T lymphocytes under good manufacturing practice conditions: tissue culture bag critically determines cell yield.

BACKGROUND: For our clinical immunogene therapy study for the treatment of renal cell carcinoma (RCC) patients, we had developed a protocol for gene transduction and expansion of human T cells in compliance with good manufacturing practice (GMP) criteria. Critical to our successful clinical-scale transductions of patient T cells was the use of Retronectin in combination with Lifecell X-foldtrade mark cell culture bags. METHODS: In our current study, we evaluated two alternative types of bags for the Retronectin-mediated retroviral transduction of human T cells: the Miltenyi DC-generation bag and the Takara CultiLife Spin bag. RESULTS: In static transductions, but not in spinoculation, the DC-generation bags and CultiLife Spin bags performed as well as Lifecell X-foldtrade mark bags in Retronectin-assisted retroviral transduction of human T cells with respect to transduction efficiency, lymphocyte subset composition and lymphocyte function. However, both types of bags performed less well than Lifecell X-foldtrade mark cell culture bags in terms of cell yield. DISCUSSION: Adjusted numbers of cells at the start of transduction should be used when using the Miltenyi or Takara bags in order to compensate for the lower cell yield following transduction.

Retroviral vectors for clinical immunogene therapy are stable for up to 9 years.

Recombinant retroviruses are one of the most commonly used gene transfer vehicles for therapeutic gene delivery. The stability of viral vectors upon long-term storage, anticipated to be short lived, is expected to impact timeline and financial course of clinical immunogene therapy. However, to date little is known about vector stability. Therefore, we analyzed the stability of retroviral vectors produced in culture supernatants (RTVsup) for ex vivo gene therapy upon long-term storage. We have generated RTVsups derived from two packaging cell lines, PG13 and Phoenix(Ampho). Both lines produced murine leukemia virus-derived SFG-scFv(G250)-CD4gamma vector, which were pseudotyped with the gibbon ape leukemia virus envelope and amphotropic envelope, respectively. The supernatants were stored at -80 or -196 degrees C. To date, the PG13-derived RTVsups have been evaluated over a period of 9 years (1998-2007). In addition, a clinical batch of Phoenix(Ampho)-derived RTVsup has been evaluated over a period of 5 years (2002-2007). Here, we show that both RTVsups, when stored up to 9 and 5 years, respectively, do not show any sign of decay in their capacity to functionally transduce primary human T cells. These data provide evidence that in terms of 'life expectancy' the production and storage of clinical batches of RTVsup for gene therapy warrants the corresponding professional and financial risks.