Real-world survival results of metastatic melanoma patients treated with ipilimumab in the Netherlands

Background

Since 2012 ipilimumab is available for metastatic melanoma patients in the Netherlands. We investigated the survival of this treatment in real-world clinical practice.

Methods

Data were retrieved from the Dutch Melanoma Treatment Registry (DMTR), follow up data cut-off April 14^th 2016. This registry records detailed data on tumor and patient characteristics, systemic treatment, grade 3 and 4 adverse events (according to the CTCAE v. 4), outcome and resource use of all patients with unresectable stage IIIc and stage IV melanoma. Kaplan-Meier estimates are used to assess the median overall survival (OS) and survival rates.

Results

From July 2012 until April 2016, 891 patients received at least one cycle of ipilimumab. 458 patients (51%) had received a previous therapeutic regimen. A shift towards applying ipilimumab in treatment naïve patients with metastatic melanoma was seen from February 2014 as at that time approval by the National Health Care Institute was obtained for this patient group. Median follow-up was 21 months (95% CI 18.6-23.3) for previously treated patients and 11.3 months (95% CI 10.4-12.3) for treatment naïve patients. The median overall survival for previously treated patients was 8.0 months (95% CI 6.8-9.3) with a one year survival rate of 37% (95% CI 32-42) and a two year survival rate of 24% (95% CI 19-28). In this group, patients presenting with normal LDH (71%) had a median OS of 9.9 months (95% CI 8.4-11.5). For treatment naïve patients the median overall survival was 14.5 months (95% CI 11.8-17.3) and the one-year survival rate was 54% (95% CI 48-60). Two-year survival rate could not be calculated because the follow-up duration was too short.

Conclusions

The discrepancy between real-world one year survival rates of previously treated patients receiving ipilimumab and pivotal trial results could be due to more stringent patient selection in clinical trials. Inexperience with disease management outside of a controlled clinical trial may have contributed as well. Importantly, two year survival rates for previously treated patients and one year survival rate of treatment naïve patients are consistent with patient outcome found in clinical trials with ipilimumab.

Clinical trial identification

Data is retrieved from a registry. Trial protocol number is not applicable.

Legal entity responsible for the study

Dutch Society for Medical Oncology (NVMO)

Funding

1. The Netherlands Organisation for Health Research and Development (ZonMw); 2. Roche; 3. Bristol- Myers Squibb (BMS); 4. MSD; 5. Novartis Oncology.

Disclosure

A. van den Eertwegh: Advisory/consulting role: BMS, Roche, MSD, Novartis, GSK Research funding: Roche. G. Groenewegen: Speakers bureau Astellas. J-W. de Groot: Consulting/ advisory role: Servier, Amgen, BMS, Bayer, Celgene, Merck, Roche. J.B.A.G. Haanen: Consulting/Advisory role: BMS, MSD, Roche, Novartis, Pfizer, Neon Research funding: BMS, GSK, MSD. R. Koornstra: Consulting/Advisory role: BMS, MSD, Roche, Novartis Honoraria: MSD. W. Kruit: Consulting/Advisory role: BMS, Novartis, GSK. D. Piersma: Consulting/Advisory role: Amgen, Novartis Research Funding: Novartis, Astra Zeneca, BMS. R. van Rijn: Consulting/Advisory Role: BMS, Amgen, Takeda Research funding: Celgene, GSK. G. Vreugdenhil: Consulting/Advisory role: BMS. M. Wouters: Research funding: Novartis. All other authors have declared no conflicts of interest.