Abstract 1048P
Background
Anti PD1(L)1 show improved overall survival (OS) benefits over conventional treatments in several cancer types. However, the optimal therapy duration for responder patients is still debated. This study aimed to provide real-life data across different tumor types after anti PD(L)1 discontinuation for patients who stopped immunotherapy without disease progression.
Methods
Data from patients treated at Cochin Hospital and Georges Pompidou European Hospital between January 2015 and December 2019 with anti PD(L)1 monotherapy, for whom treatment was discontinued within the first 2 years without disease progression were retrospectively analyzed. Long term outcomes and clinical and biological factors associated with survival were assessed. Cox proportional hazard regression models were used for survival analyses.
Results
At the time of analysis, 69 patients (51% NSCLC) treated with anti PD(L)1 had stopped therapy without disease progression, because of controlled disease (54%, including 26% of complete response (CR)), or adverse event (46%). The median treatment duration was 6.9 months (0.5-24.6). Median progression free survival after therapy discontinuation (dPFS) was 11.9 months, 95%CI [10.3-NA] and the median OS was not reached after a median follow up of 29 months. In univariate analysis, the type of response seemed to have an impact on OS (CR vs PR: HR 9.01, p = 0.036). A longer therapy duration was significantly associated with longer OS (HR 0.908, p=0.047). Discontinuation after 6 months was associated with longer dPFS (HR 0.506, p =0.0471) and OS (HR 0.3, p = 0.031) than within the first 6 months. Similar results were found among complete responders. Discontinuation because of adverse event rather than controlled disease was associated with shorter OS (HR 2.9; p=0.048). Secondary progression occurred in 36 patients (56%), of whom 21 received treatment rechallenge, with 33% ORR and 21% CR rate.
Conclusions
These results suggest that patients who do not experience disease progression and discontinue antiPD(L)1 therapy before 2 years may have long term benefits and can benefit from treatment rechallenge. Patients treated for less than 6 months seem to have poorer prognosis, even among complete responders.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
P. Boudou Rouquette: Officer/Board of Directors: Takeda; Officer/Board of Directors: BMS; Travel/Accommodation/Expenses: Takeda; Travel/Accommodation/Expenses: PharmaMar. O. Huillard: Honoraria (self): Sanofi; Honoraria (self): BMS; Honoraria (self): AstraZeneca; Honoraria (self), Travel/Accommodation/Expenses: Pfizer; Honoraria (self): Novartis; Travel/Accommodation/Expenses: Roche; Travel/Accommodation/Expenses: Astellas; Travel/Accommodation/Expenses: Ipsen; Travel/Accommodation/Expenses: Sanofi. M. Wislez: Honoraria (self): Roche; Honoraria (self): Pfizer; Honoraria (self): AstraZeneca; Honoraria (self): BMS; Honoraria (self): Boehringer Ingelheim. F. Goldwasser: Speaker Bureau/Expert testimony, Officer/Board of Directors: Baxter; Advisory/Consultancy, Officer/Board of Directors: Nutricia; Advisory/Consultancy, Officer/Board of Directors: Fresenius. All other authors have declared no conflicts of interest.