Circulating tumor DNA provide valid way to monitor response to anti-PD-1 therapy for melanoma....AGAIN!!!

I keep reporting NEWS that is no longer NEWS!!!!   In March I posted this report which includes links to abstracts going back to 2014!  Circulating DNA predicts response to anti-PD1  "Well, 2014 is not so long ago," you say?  Not in melanoma world my friend!  3 years represents untold quantities of pain and suffering and loss of dear ratties!!!

So....here's the 'NEWS':

Circulating tumor DNA changes for early monitoring of anti-PD1 immunotherapy: a proof-of-concept study. Cabel, Riva, Servois, et al. Ann Oncol. 2017 Apr 29.

Recent clinical results support the use of new immune checkpoint blockers (ICB), such as anti-PD-1 (e.g. nivolumab, pembrolizumab) and anti-PD-L1 antibodies. Radiological evaluation of ICB efficacy during therapy is challenging due to tumor immune infiltration. Changes of circulating tumor DNA (ctDNA) levels during therapy could be a promising tool for very accurate monitoring of treatment efficacy, but data are lacking with ICB.

This prospective pilot study was conducted in patients with non-small cell lung cancer, uveal melanoma or microsatellite-instable colorectal cancer treated by nivolumab or pembrolizumab monotherapy at Institut Curie. ctDNA levels were assessed at baseline and after 8 weeks by bidirectional pyrophosphorolysis-activated polymerization, droplet digital PCR or next-generation sequencing depending on mutation type. Radiological evaluation of efficacy of treatment was performed by using immune-related response criteria.

ctDNA was detected at baseline in 10 out of 15 patients. At w8, a significant correlation was observed between synchronous changes in ctDNA levels and tumor size. Patients in whom ctDNA levels became undetectable at w8 presented a marked and lasting response to therapy. ctDNA detection at w8 was also a significant prognostic factor in terms of progression-free survival and overall survival. 

This proof-of-principle study is the first to demonstrate that quantitative ctDNA monitoring is a valuable tool to assess tumor response in patients treated with anti-PD-1 drugs.

Can we move forward...NOW!!!???  Week 8!!!  Institut Curie!!  (Of, course!) Hang tough, ratties! - c