Cancer experts discussed the prospects and pitfalls in current management strategies in prostate cancer particularly those involving emergent treatments such as immunotherapy and standard medical options represented by chemotherapy.
At the second-half of the day-long EAU-ICUD Consensus Meeting on the Medical Treatment of Urological Malignancies held today in Lisbon, Portugal, the discussions in the concluding sessions tackled vaccines, immunotherapy and gene-based strategies in prostate cancer, on the one hand, and cytotoxic chemotherapy and targeted agents on the other.
Charles Drake (Baltimore, USA) gave an overview on immunotherapy and other alternative treatments discussing topics such as dendritic-cell based vaccine approaches, the use of prostatic acid phosphatase as a vaccine target antigen, Pox Viral-based vaccines, antibody-based therapy and immune checkpoint inhibition.
“Dendritic cell-based vaccines are promising but challenging strategies,” said Drake as he noted that a lot of work needs to be done particularly in the area of guidelines. Regarding DNA-based vaccines, he underscored the flexibility of this treatment as its key attribute.
On the other hand, the jury is still out regarding Pox-virus based vaccines, with phase 3 trials still in progress. On the issue of anti-cancer antibodies, lutetium radiolabeled anti-PSMA antibody J591 is still undergoing trials.
Finally, on immune checkpoint blockade, Drake said the latest results were disappointing in late-stage disease. “But on early disease stages, its prospects are still being explored,” he added.
The last session took up cytotoxic chemotherapy and targeted agents, with Anders Bjartell (Malmo, Sweden) giving a comprehensive overview of the various issues in the chemotherapy of prostate cancer.
Bjartell said the committee on cytotoxic chemotherapy aimed to cover pathophysiology, biomarkers, predictive models, available treatments and international guidelines in managing and monitoring treatments.
Among Bjartell’s key messages are:
- Chemotherapy with docetaxel has been the first treatment that provided an overall survival (OS) benefit in metastatic castration resistant prostate cancer;
- Taxanes exert an AR-axis mediated anti-prostate cancer effect which maybe the background for future combinations with other AR-directed agents;
- Beyond chemotherapy and novel hormonal treatments, the rapid drug development has led to significant uncertainties as to how to make best use of novel treatments;
- Biomarkers are still under development;
- Mechanisms of resistance to cytotoxic chemotherapy and targeted agents in mCRPC are multi-factorial and often depends on tumour heterogeneity; and
- Studies on the optimal sequence and combination of agents are urgently needed.