For teams planning a non-small cell lung cancer (NSCLC) submission, the endpoint and control arm chosen at protocol design are among the most consequential decisions in the program. Whether the FDA will accept a given primary endpoint or comparator turns on the line of therapy, the drug's mechanism, and the intended approval pathway — and getting it wrong can cost a trial its registrational value. Grounding those choices in what the agency has actually accepted across prior NSCLC reviews reduces regulatory risk before the first patient is enrolled.
The analysis below draws on recent Drugs@FDA reviews to set out the conventions that have governed endpoint and comparator selection in NSCLC. It organizes the precedent by clinical context — second-line versus first-line disease, checkpoint inhibitors versus biomarker-targeted agents, and regular versus accelerated approval — and identifies the recurring patterns that connect them, with each convention tied to the specific trials that established it.
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FDA-accepted primary endpoints and comparator designs in NSCLC trials
The endpoints and control arms the FDA has accepted in non-small cell lung cancer (NSCLC) are not uniform. They track three variables: the line of therapy, whether the drug is an immune checkpoint inhibitor or a biomarker-targeted agent, and whether the sponsor is pursuing regular or accelerated approval. Reading across recent Drugs@FDA reviews, a small number of durable conventions emerge, each anchored to a specific clinical context. This overview sets out those conventions and the patterns that link them.
Second-line disease: overall survival against docetaxel
The clearest fixed point in the NSCLC evidence base is the second-line (post-platinum) control arm. When a drug is tested after progression on platinum-based chemotherapy, the FDA has repeatedly accepted docetaxel 75 mg/m² every three weeks as the standard comparator, with overall survival (OS) as the primary endpoint for immunotherapy programs.
- Nivolumab's second-line squamous NSCLC trial (CheckMate 017) used OS as the major efficacy outcome against docetaxel 75 mg/m² every three weeks 100101104117.
- Atezolizumab's OAK and POPLAR trials both carried OS as the primary endpoint versus docetaxel. In OAK, median OS was 13.8 months with atezolizumab versus 9.6 months with docetaxel (HR 0.74, p=0.0004); POPLAR showed 12.6 versus 9.7 months (HR 0.69) 40414952. PD-L1 expression was not required for entry into either trial; patients were randomized and then analyzed by PD-L1 subgroup 40435153.
Docetaxel's role as the accepted second-line control is durable enough that it now serves as the comparator not only for checkpoint inhibitors seeking regular approval, but also for the randomized confirmatory trials that follow single-arm accelerated approvals of targeted agents (see below).
First-line immunotherapy: OS and PFS against a chemotherapy (or placebo-plus-chemotherapy) control
In the first-line metastatic setting, checkpoint-inhibitor programs have converged on overall survival and progression-free survival (PFS) as co-primary or dual endpoints, with the comparator determined by whether the drug is used as monotherapy or added to chemotherapy.
- For chemotherapy-combination regimens, the control is the same chemotherapy backbone plus placebo. KEYNOTE-189 (nonsquamous) compared pembrolizumab plus pemetrexed and platinum against placebo plus pemetrexed and platinum, reporting median OS of 22.0 versus 10.6 months (HR 0.56); KEYNOTE-407 (squamous) compared pembrolizumab plus carboplatin and a taxane against placebo plus the identical chemotherapy regimen. Both carried OS and PFS as primary endpoints 6263.
- For monotherapy in biomarker-selected patients, the control is chemotherapy alone and enrollment is restricted by PD-L1 expression. KEYNOTE-024 enrolled first-line patients with a PD-L1 tumor proportion score (TPS) of 50% or greater, used OS as the primary endpoint, and compared pembrolizumab monotherapy against platinum-based chemotherapy 142.
The pattern is consistent: the experimental arm is layered onto, or measured against, the prevailing standard of care, and the addition of a placebo to the chemotherapy control preserves blinding when the immunotherapy is given on top of chemotherapy.
Biomarker-targeted therapy: randomized trials against an active comparator, PFS primary
For oncogene-driven NSCLC with an established standard-of-care drug, the FDA has accepted randomized trials against an active comparator with PFS as the primary endpoint, typically assessed by blinded independent central review.
- EGFR-mutant, first-line: Osimertinib's FLAURA trial used PFS as the primary endpoint against a standard-of-care EGFR TKI (gefitinib or erlotinib) 174. Earlier EGFR TKIs were held to the same structure against a chemotherapy control: afatinib's LUX-Lung 3 (Study 1200.32) used IRC-assessed PFS against cisplatin/pemetrexed 2135, dacomitinib's ARCHER 1050 used IRC-reviewed PFS against gefitinib 1623, and erlotinib's first-line program used PFS 6.
- EGFR-mutant, second-line (T790M): Osimertinib's AURA3 trial compared the drug against platinum-based doublet chemotherapy (pemetrexed with carboplatin or cisplatin) in patients who had progressed on prior EGFR TKI therapy 31173.
- ALK-positive, first-line: The accepted comparator has been crizotinib, with PFS as the primary endpoint. Alectinib's ALEX trial used investigator-assessed PFS against crizotinib 250 mg twice daily 8488; lorlatinib (CROWN) and brigatinib (ALTA-1L) both used BICR-assessed PFS against crizotinib 224227228.
Across these programs the logic is the same: where an effective targeted or cytotoxic standard exists, the FDA expects a head-to-head randomized comparison, and PFS is accepted as the primary measure of benefit for the marketing application.
Single-arm accelerated approvals: ORR and duration of response for rare drivers
For NSCLC defined by rarer molecular alterations, where randomization is difficult and no dedicated standard exists, the FDA has accepted single-arm trials with objective response rate (ORR) and duration of response (DoR) as the primary endpoints, supporting accelerated approval. Response is consistently assessed by RECIST v1.1 under blinded independent central review.
- KRAS G12C: Sotorasib's accelerated approval rested on ORR and DoR from CodeBreaK, endpoints the review described as accepted in NSCLC, with no comparator arm 156. Adagrasib's approval came from the single-arm KRYSTAL-1 Cohort A (Study 849-001), with ORR by independent central review as the primary endpoint and no comparator 130131133137.
- EGFR exon 20 insertions: Amivantamab's accelerated approval used ORR by BICR as the primary endpoint in the single-arm exon 20 insertion cohort of CHRYSALIS (81 previously treated patients), with no comparator arm 175176184187190. Mobocertinib's approval in the same population relied on ORR, DoR, PFS and OS from a single-arm design 25.
- RET fusions: Selpercatinib (LIBRETTO-001/LOXO-RET-17001) and pralsetinib (ARROW/BLU-667-1101) were both approved on single-arm ORR by RECIST 1.1 under blinded independent review, with no control arm 8.
- MET exon 14 skipping: Tepotinib's approval drew on the single-arm VISION study with ORR and DoR and no comparator 198.
Cross-cutting patterns across recent approvals
Several recurring features stand out when these programs are read together.
The comparator is dictated by the standard of care, not the mechanism. Docetaxel is the accepted second-line control 1001011044041; chemotherapy or chemotherapy-plus-placebo is the first-line immunotherapy control 6263142; crizotinib is the accepted first-line ALK comparator 84224228; and an established EGFR TKI or platinum doublet is the EGFR comparator 17431173. The FDA holds each new agent against whatever patients would otherwise receive.
Endpoint choice follows the approval pathway. Regular approvals of checkpoint inhibitors have leaned on OS, alone or paired with PFS 1004062142. Randomized targeted-therapy approvals have leaned on PFS by independent review 17484228. Accelerated approvals for rare-driver disease have relied on ORR and DoR from single-arm cohorts 1561301758198.
Single-arm accelerated approvals carry a randomized confirmatory obligation, and that confirmatory trial reverts to docetaxel. Sotorasib's confirmatory study (Study 20190009) was a phase 3 randomized, open-label, active-controlled trial of sotorasib versus docetaxel in previously treated KRAS G12C NSCLC, with PFS as the primary endpoint 156157223. Adagrasib's review likewise flagged a required randomized comparison against docetaxel as a postmarketing commitment rather than the basis for initial approval 129134140. The second-line docetaxel control thus reappears as the mechanism for confirming clinical benefit after an ORR-based accelerated approval.
Independent, blinded assessment is the norm for response and PFS. Whether the endpoint is ORR in a single-arm trial or PFS in a randomized one, recent reviews consistently describe assessment by blinded independent central review under RECIST v1.1 17584227130, reflecting the FDA's expectation of centrally adjudicated radiographic endpoints where the primary measure is not survival.
Taken together, the NSCLC record shows a stable grammar: OS against docetaxel in the second line, OS and PFS against chemotherapy in the first line for immunotherapy, PFS against an active comparator for targeted agents where a standard exists, and single-arm ORR and DoR for rare drivers, each accelerated approval tethered to a randomized docetaxel-controlled confirmatory trial. A reader weighing a specific program can ask Rhizome to pull the exact hazard ratios, PD-L1 assay details, or confirmatory-trial status for any of the drugs named here.