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Sipuleucel-T in prostate cancer: Indication of added benefit

Date:
March 20, 2015
Source:
Institute for Quality and Efficiency in Health Care
Summary:
Regarding Sipuleucel-T for use in prostate cancer, information submitted by the drug manufacturer provided better evidence on mortality. However, it is not possible to exactly estimate the extent of added benefit.
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Sipuleucel-T (trade name Provenge) has been approved since September 2014 for men with metastatic prostate cancer who have few or no symptoms and do not yet require chemotherapy. In the dossier assessment conducted by the German Institute for Quality and Efficiency in Health Care (IQWiG) in January 2015, no added benefit could be derived for sipuleucel-T.

In an addendum, the Institute now examined information subsequently submitted by the manufacturer in the commenting procedure: According to the findings, there is an indication of added benefit; however, the extent is non-quantifiable.

Mortality: data in the dossier incomplete and not interpretable

Treatment switching occurred in all three approval studies comparing sipuleucel-T with placebo, which were presented in the dossier by the manufacturer: More than two thirds of the patients in the placebo group started treatment with sipuleucel-T on progression of their disease. In both study arms, patients received chemotherapy with docetaxel on progression. The proportion of patients who received docetaxel and the time point of this treatment differed, however, and the respective information provided in the dossier was incomplete.

The study results on overall survival in the dossier could therefore not be interpreted in a meaningful way: Docetaxel has a positive effect on survival. If, for example, it is given at an earlier time point in the sipuleucel-T arm than in the control arm, lower mortality cannot be explained solely by the effect of sipuleucel-T. Then there is a risk of overestimating the effect of sipuleucel-T.

Additional analyses showed advantage in mortality

The manufacturer presented further data and sensitivity analyses on overall survival with its comment. This now led to a consistent picture in comparison with the primary analysis of the data in the dossier: According to this, the lower mortality in the sipuleucel-T arms cannot be explained solely by differences in the administration of docetaxel after progression.

However, the advantages in overall survival are accompanied by negative effects in the form of side effects: Fever, headache and chills were more frequent in patients in the sipuleucel-T arm. However, these side effects were non-serious and mainly occurred only directly after the administration of sipuleucel-T. IQWiG therefore did not downgrade the positive effect regarding mortality. The conclusion of the addendum for sipuleucel-T is therefore an indication of an added benefit with the extent "non-quantifiable."


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Cite This Page:

Institute for Quality and Efficiency in Health Care. "Sipuleucel-T in prostate cancer: Indication of added benefit." ScienceDaily. ScienceDaily, 20 March 2015. <www.sciencedaily.com/releases/2015/03/150320101739.htm>.
Institute for Quality and Efficiency in Health Care. (2015, March 20). Sipuleucel-T in prostate cancer: Indication of added benefit. ScienceDaily. Retrieved May 23, 2017 from www.sciencedaily.com/releases/2015/03/150320101739.htm
Institute for Quality and Efficiency in Health Care. "Sipuleucel-T in prostate cancer: Indication of added benefit." ScienceDaily. www.sciencedaily.com/releases/2015/03/150320101739.htm (accessed May 23, 2017).

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