It’s always better when we’re together.
The Study: As predicted, the phase 2 Gomez data indicating a 2-fold improvement in survival with the addition of early consolidative stereotactic body radiation (SBRT) for oligometastatic non-small cell lung cancer (NSCLC) has left the token antagonistic med onc saying: That’s great, but now re-do the whole thing in patients receiving pembro. One issue is that, these days, patients with ≥50% tumor expression of PD-L1 generally receive pembro monotherapy for at least 2 years. So there’s no clear juncture to add SBRT. Should it be upfront, after a few cycles if no progression, or only if and when there is progression? Probably not the last option since the Gomez data suggests waiting until progression is waiting too long. This phase 1 trial offers up more clues. It enrolled 18 patients with metastatic urothelial carcinoma receiving pembro at the same dose and schedule as that used for NSCLC and randomized them to  sequential upfront SBRT prior to pembro or  concurrent SBRT just before the third cycle of pembro. All SBRT consisted of 8 Gy x 3 to a single metastatic lesion. The only grade 3 toxicity was lymphopenia 11 months after SBRT. Of course this was not powered to show a difference in these regards, but we’ll note that any response occurred in 0 patients in the sequential arm and 4 in the concurrent arm while respective median survival times were 4.5 and 12 months.
Bottom Line: Early consolidative SBRT for oligomets concurrent with pembro infusions comes at the low low price of 1-5 days time and grade 1-2 toxicity, with all available data suggesting a synergistic therapeutic effect. | Sundhal, Eur Urol 2019