Show of hands, who remembers the children’s game, I Spy? (Time for an obligatory ‘80s reference: Anyone…? Anyone…? Bueller…? Bueller…?) For those that don’t remember, Wikipedia states, “I spy is a guessing game where one player chooses an object within sight and announces to the other players that ‘I spy with my little eye something beginning with…’, naming the first letter of the object. Other players attempt to guess this object.”
Our take on this same game is one that we call “We spy with our imaging eye”. Here we present an image from a patient that underwent treatment and challenge you, the reader, to guess the answer from a multiple-choice question based on that image.
Got it?
Ok, then, “we spy with our imaging eye a tumor from a patient with treatment-resistant angiosarcoma that received lead EpicentRx therapy, AdAPT-001, and a checkpoint inhibitor.” So, a) did the tumor improve after therapy with AdAPT-001? b) did it get worse after therapy with AdAPT-001? or c) both.
The answer is c, both.
How is that possible?
Well, as shown below, after one month of treatment, this patient met the definition of progression, since his tumor was considerably larger. However, because the patient felt better symptomatically, he was continued on treatment. Subsequent images revealed regression of the tumor, confirming pseudoprogression, which imitates real progression, and which is associated with better overall survival, perhaps because it involves an active “inflammatory” response against the tumor. It is important for physicians and patients to understand that pseudoprogression occurs commonly with AdAPT-001 + a checkpoint inhibitor and, if suspected, cautious continuation of treatment is usually recommended despite what appears for all the world to be disease progression.
