Pembrolizumab plus enzalutamide for enzalutamide-resistant metastatic castration-resistant prostate cancer (mCRPC): Updated analyses after one additional year of follow-up from cohorts 4 and 5 of the KEYNOTE-199 study.
Bibliographic record
Abstract
5042 Background: KEYNOTE-199 (NCT02787005) is a multicohort phase 2 study to evaluate pembrolizumab (pembro) in mCRPC. A previous analysis of patients with RECIST-measurable (cohort 4 [C4]) or bone-predominant nonmeasurable (cohort 5 [C5]) disease who were chemotherapy-naive and had progression while on enzalutamide (enza) found that pembro + enza showed antitumor activity and manageable safety. Long-term outcomes are of interest with immunotherapy; hence, updated efficacy and safety data after an additional 1 year of follow-up are presented. Methods: Pts were eligible if they had resistance to enza after prior response. Prior treatment with abiraterone was allowed. Pts received pembro 200 mg Q3W for up to 35 cycles + enza QD until progression, unacceptable toxicity, or withdrawal. Primary end point was ORR per RECIST v1.1 by blinded independent central review (BICR) in C4. Secondary end points were DOR (C4), and DCR, rPFS, OS and safety (both cohorts). Results: 126 pts (C4, 81; C5, 45) were treated. Median age was 72 years (range 43-92), 32.5% had visceral disease and 87.3% previously received ≥6 mo of enzalutamide; 121 pts (96.0%) discontinued, most because of progressive disease. Median (range) time from enrollment to data cutoff was 31.7 mo (23.1-37.1) in C4 and 35.5 mo (22.9-37.3) in C5. In C4, confirmed ORR was 12.3% (95% CI 6.1-21.5) (2 CRs, 8 PRs); median (range) DOR was 8.1 mo (2.5+ to 15.2), and 62.5% had a response ≥6 mo (Kaplan-Meier estimate). Additional efficacy analyses are outlined in the table. A total of 27.2% and 28.9% of pts in C4 and C5, respectively, experienced grade ≥3 treatment-related adverse events. Two pts in C4 died of immune-related AEs (Miller Fisher syndrome and myasthenia gravis). Incidence of any-grade (34.1%) and grade 3 or 4 (5.6%) rash, regardless of relatedness to treatment, was higher than previously reported for individual agents but manageable with standard-of-care treatments; 2 pts discontinued because of rash. Conclusions: After an additional 1 year of follow-up, pembro + enza continued to show antitumor activity and a manageable safety profile in pts with mCRPC who became resistant to enza. The treatment combination is being further evaluated in the ongoing phase 3 KEYNOTE-641 trial (NCT03834493). Clinical trial information: NCT02787005. [Table: see text]
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".