Outcomes of patients (pts) treated with novel immunotherapy (IT) agents in phase 1 clinical trials (Ph1-CT) at early lines for advanced disease

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Background: The overall survival (OS) benefit observed with immune checkpoint inhibitors led to their approval in many tumor types. Given the large number of IT compounds in early clinical development, many pts are offered IT within Ph1-CT even before having exhausted standard of care (SOC) therapies. We assessed outcomes of pts receiving novel IT treatments within Ph1-CT at the Phase 1 Unit of Catalan Institute of Oncology (ICO), Barcelona, Spain. Methods: We retrospectively reviewed a correlative series of pts with advanced/metastatic solid tumors treated with IT within Ph1-CT at ICO from January 2018 to June 2021. Primary endpoint was to assess clinical outcomes measured by median progression-free survival (mPFS) and median OS (mOS) according to number of prior lines (PL) for recurrent/metastatic disease, grade 3-4 toxicity (G3-4 Tox) and age. Data on prior IT (yes vs no) and availability of alternative SOC were evaluated. Overall response rate (ORR) was assessed according to RECIST 1.1. Clinical benefit rate (CBR) was defined as complete/partial response + stable disease for ≥6 months (m). PFS/OS were calculated by Kaplan-Meier method. Log-rank test was used for comparisons. Median PFS of alternative SOC according to historical data was recorded by tumor type and line of treatment. Results: A total of 104 pts received IT within Ph1-CT: IT monotherapy = 39 (37.5%), IT combinations = 65 (62.5%) (IT+IT = 59 [90.8%], IT+targeted therapy = 6 [9.2%]). Median age was 54 y (42-77), 62.5% were men and all had ECOG 0-1. Four most frequent cancers were urothelial (19.2%), colorectal (15.3%), head & neck (12.5%) and glioblastoma (11.5%). Number of PL: 0 = 20 (19.2%) pts, 1 = 37 (35.6%) pts, ≥2 = 47 (45.2%) pts. Nine (8.6%) pts had received prior IT. G3-4 Tox rate for the overall population was 19.2% and for pts who had received prior IT was 33%. ORR was 11.5%; CBR was 24%. Overall mPFS and mOS were 2.7m and 8.6m, respectively. Pts with less PL had greater mPFS and mOS (p < 0.05) (Table). Pts with available alternative SOC had lower mPFS but similar mOS compared to historical SOC (2.6m vs 4.8m, 11.4m vs 11.8m, respectively). G3-4 Tox (yes vs no) and age ( < 70 vs ≥70) did not significantly impact on mOS or mPFS (p = 0.18 and p = 0.83, respectively). At end of Ph1-CT treatment, 47 (45.2%) pts worsened their ECOG status, 15 (14.4%) pts were enrolled in a subsequent trial and 22 (21.1%) pts received SOC. Conclusions: In our cohort of pts treated with novel IT within Ph1-CT, overall clinical outcomes were modest in terms of mPFS, mOS, and CBR. However, pts with less pre-treated tumors seem to achieve higher survival benefit from early treatment with IT within Ph1-CT, although this benefit remains unclear in pts with alternative SOC. [Table: see text]

Analysis of phase I clinical trials (Ph1-CT) new enrollment patterns in the immuno-oncology era

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Background: Immuno-Oncology (IO) has revolutionized anticancer therapeutics and changed the early drug development paradigm. Positive results and limited access to IO drugs in some countries have led to increased enrollment in IO Ph1-CT at an earlier timepoint in patients (pts) disease journey. We evaluated the impact of IO era on enrollment patterns in Ph1-CT. Methods: We retrospectively reviewed pts with recurrent/metastatic solid tumors enrolled in Ph1-CT from January 2018 to June 2021 at the Phase 1 Unit of Catalan Institute of Oncology (ICO), Barcelona, Spain. The primary goal was to assess Ph1-CT enrollment patterns, including use of molecular pre-screening/personalized drug matching, and the availability of alternative standard of care (SOC). Overall response rate (ORR) was assessed according to RECIST 1.1. Clinical benefit rate (CBR) was defined as complete/partial response+stable disease for ≥6 months. Median progression-free survival (mPFS) and overall survival (mOS) using Kaplan-Meier method were provided. Results: A total of 175 pts were enrolled in Ph1-CT. Median age was 54 years (range 43-75), Male:Female = 99:76, 99% had ECOG 0-1. The most prevalent tumors were: 32 (18%) breast, 31 (18%) colorectal, 25 (14%) urogenital and 23 (13%) glioblastoma multiforme. One hundred forty-six (83%) pts were enrolled in Ph1-CT with IO (alone or in combination) and 29 (17%) pts with targeted therapy (TT). Molecular pre-screening tests were required in 24 (14%) pts (22 pts IO vs 2 pts TT trial). Eleven (42%) pts were pre-screening failures. Screening failure (SF) rate was 19%, the main reason being clinical worsening for 7 (4%) pts. Thirty-three (19%) pts had an alternative SOC treatment available at time of enrollment. One hundred two (58%) pts had received ≤1 prior lines and 26 (89%) were IO-naïve. Finally, 129 (74%) out of 175 pts enrolled were treated within Ph1-CT. Out of 129 treated pts, ORR was achieved in 18 (14%) pts (3% complete response) and 44 (34%) had stable disease. CBR was observed in 36 (28%) pts. mPFS was 2.8 months and mOS was 10.9 months. Toxicity grade 3-4 occurred in 25 (19%) of pts and 6 (5%) pts had to interrupt treatment. Seventy-one (55%) pts received subsequent therapies: 22 (17%) in Ph1-CT; 49 (38%) SOC. Eleven (9%) pts received IO as subsequent therapy. Decline in ECOG status (baseline vs end of treatment) occurred in 65 (50%) pts. Conclusions: In our cohort of Ph1CT pts, there has been an increasing number of pts enrolled in IO trials compared to TT. Most pts received treatment within Ph1-CT at an earlier timepoint in the course of their disease (1st or 2nd lines). Our results suggest a clear impact of the IO era on the trends of Ph1-CT availability and enrollment patterns.