Arcus Biosciences' AB928 combination immunotherapy trial. The 18-month enrollment benchmark is the key number — here's where PEAK-1 sits against it and what protocol-change scenarios look like.
The 18-month benchmark: Industry data (Tufts CSDD) shows Phase II oncology immunotherapy trials that miss their 18-month enrollment milestone have a 72% probability of requiring a protocol amendment, timeline extension, or site expansion — each adding $1–3M in unplanned costs. PEAK-1's current trajectory warrants a closer look.
Trial fact panel — sourced from ClinicalTrials.gov
NCT ID
NCT07011719
Sponsor
Arcus Biosciences
Short Name
PEAK-1
Phase
Phase II
Target N
~240
Registered Sites
12–15
Status
Recruiting
Primary Endpoint
ORR / PFS
Indication
GI Oncology
Combination regimen: AB928 (adenosine receptor antagonist) + zimberelimab + standard chemotherapy. Triple-combination eligibility criteria are meaningfully more restrictive than PD-1 monotherapy — prior treatment line constraints and organ function cutoffs reduce the eligible pool at each site vs. simpler immunotherapy designs.
71
High Risk
Enrollment Risk Score: 71 / 100
PEAK-1 scores High Risk. The combination eligibility criteria compress the per-site eligible pool materially vs. GI benchmarks. At 12–15 sites and standard oncology enrollment rates, the 18-month milestone requires consistent outperformance — historically achieved only by trials with active patient-matching infrastructure.
0255075100
Top 3 risk drivers
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18-month enrollment benchmark pressure
Phase II GI immunotherapy at 12–15 sites with N=240 implies a required rate of ~1.3 patients/site/month. Tufts CSDD Phase II GI benchmark is 0.9–1.1 without active patient matching. Gap is real and doesn't close passively.
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Triple-combination eligibility attrition
Each added agent in a combination regimen typically eliminates 20–30% of otherwise-eligible patients at screen. AB928 + zimberelimab + chemo has 3 eligibility "gates." Cascade screen-fail rates for triple combinations run 45–60% vs. 25–35% for PD-1 monotherapy.
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Protocol-change exposure
Combination immunotherapy trials in GI have a 58% amendment rate in the first 24 months (Tufts CSDD). Each amendment re-screens the eligible pool — without a live patient matching system, re-screening is manual and loses 3–6 weeks per site.
Protocol Change Impact — PEAK-1 scenario
What happens to PEAK-1's eligible pool if the AB928 dosing arm is amended mid-trial? Modeled on a real protocol change pattern for Phase II combination immunotherapy.
Before amendment
38%
Screen-fail rate (manual, pre-amendment)
11
Avg days to re-contact per site per amendment
~28
Eligible patients per site at current criteria
With Syncra re-matching
22%
Screen-fail rate (automated re-screen)
<24h
Time to re-score eligible pool post-amendment
~34
Net eligible after broader criteria applied
↑ +6 patients/site on amendment
At 15 sites, that's ~90 additional enrollable patients surfaced within 24 hours of an amendment going live — vs. the manual process that takes 2–3 weeks to complete across a site network this size.
Enrollment trajectory — PEAK-1 18-month window
Projected pace vs. benchmark. At the current site-count and standard GI Phase II rates, PEAK-1 reaches the 18-month mark at ~74% enrolled. Syncra's outreach coordination moves the projection to ~95%.
Baseline pace (no intervention)
~74% at month 18
0%18 months100%
With Syncra (coordinated outreach + protocol re-match)
~95% at month 18
0%18 months100%
16pp
Enrollment rate lift from coordinated outreach at 18-month milestone
$2.1M
Estimated cost of a 6-month timeline extension at Parexel Phase II oncology rates
<24h
Time to re-match eligible pool after a protocol amendment
Want this for your full portfolio?
PEAK-1 is a good example of where AI-assisted patient matching changes the 18-month outcome. See what Syncra does across your active GI oncology portfolio — no integration required to start.
Data sourced from ClinicalTrials.gov + Tufts CSDD benchmarks + Parexel industry estimates. Enrollment projections are model outputs based on publicly available trial parameters; they are not clinical assessments. Syncra has no formal relationship with Arcus Biosciences.