April 1, 2026, Cancers (MDPI), a peer-reviewed, open-access oncology journal, has published the article: “Real-World Evidence of Atezolizumab Efficacy as Part of First-Line Treatment for Extensive-Stage SCLC in Bulgaria.”


This National Real-World Evidence (RWE) study, co-authored by leading Bulgarian oncologists, the National Council on Prices and Reimbursement of Medicinal Products, and Sqilline Health, provides a comprehensive assessment of a cohort receiving the anti-PD-L1 agent as part of first-line extensive-stage small-cell lung cancer (ES-SCLC) treatment.

The study was enabled by Sqilline’s Danny Platform – an AI-powered platform that structures and harmonizes unstructured oncology data at scale.

Data from 48 hospitals were transformed into standardized, research-ready datasets, enabling direct comparison with the pivotal IMpower133 clinical trial.

The study included 302 patients treated between 2022 and 2024, with a subgroup aligned to trial criteria for robust comparison.

Introduction

Small-cell lung cancer (SCLC) is a highly aggressive malignancy, accounting for 10–15% of lung cancer cases and characterized by rapid progression and poor prognosis. Despite decades of limited progress, the addition of immunotherapy to first-line chemotherapy has improved outcomes, though real-world validation remains essential.

Key Summary Points

Objectives

  • Evaluate real-world effectiveness of PD-L1 inhibitor + chemotherapy in ES-SCLC.
  • Compare real-world outcomes with the IMpower133 clinical trial.
  • Assess progression-free survival (PFS), response rates (ORR), and clinical benefit (CBR).

Challenges

  • Limited availability of real-world evidence for immunotherapy in SCLC outside clinical trials.
  • Differences in baseline patient characteristics between real-world and trial populations (age, ECOG status, smoking profile).
  • Risk of bias in cross-cohort comparisons.
  • Variability in real-world documentation impacting response rate reporting (e.g., ORR).
Solution

Danny Platform:

  • Extracted and structured real-world EHR data from 48 hospitals using ML/LLM models.
  • Enabled cohort alignment with IMpower133 criteria.
  • Applied statistical adjustment (iterative proportional fitting (IPF) to balance baseline characteristics.
  • Generated robust survival and response analyses across real-world cohorts.
Results

A total of 302 patients were included, of whom 167 met first-line eligibility criteria.
Data was collected from 48 hospitals across Bulgaria.

Insights

Long-term disease control was consistently higher in real-world settings, with improved PFS at 6, 12, and 20 months compared to the clinical trial.
Lower observed ORR is likely attributable to variability in real-world documentation rather than reduced therapeutic efficacy.

Baseline Characteristics (vs. IMpower133)

  • Median age: 66 years (vs. 64 years in trial)
  • ECOG 1 more common in real-world (80.8% vs. 63.7%)
  • Higher proportion of current smokers (~80% vs. 36.8%)

Treatment Outcomes

  • Median PFS:
    • Real-world: 7.6 months
    • IMpower133: 5.2 months (significantly lower)
  • ORR:
    • Real-world: 38.7%
    • Trial: 65.4%
  • CBR:
    • Real-world: 82.9%
    • Trial: 88.1% (comparable)

Survival Insights

  • Higher long-term disease control in real-world:
    • 6-month PFS: 58% vs. 30.9% (trial)
    • 12-month PFS: 18% vs. 12.6%
    • 20-month PFS: 13% vs. ~5%
  • Lower ORR attributed to real-world documentation practices, not reduced efficacy.
Conclusions

This study validates the PD-L1 inhibitor in real-world settings beyond IMpower133. It also demonstrates that Danny Platform can generate regulator-grade real-world evidence at a national scale – unlocking a new standard for oncology decision-making.

Authors and Affiliations
  • Manoela Manova, Boryana Ivanova, Alexandra Savova – Medical University Sofia & NCPRMP
  • Rositsa Krasteva – UniHospital, Panagyurishte
  • Nikolay Conev – UMHAT St. Marina, Varna
  • Tanya Zlatanova – Acibadem City Clinic UMHAT Tokuda, Sofia
  • Jeliazko Arabadjiev – Acibadem City Clinic UMHAT Tokuda, Sofia
  • Natalia Chilingirova – Heart and Brain Hospital, Pleven
  • Mila Petrova – MHAT Nadezhda, Sofia,
  • Assen Dudov – Acibadem City Clinic Mladost, Sofia
  • Bozhil Robev – UMHAT St. Ivan Rilski, Sofia
  • Velko Minchev – SofiaMed University Hospital, Sofia,
  • Ivan Tonev – Complex Oncology Center, Plovdiv
  • Krassimir Koynov – MHAT Serdika, Sofia
  • Antoan Rangelov – NCPRMP & Sofia University St. Kliment Ohridski, Sofia
  • Daniel Penchev, Todor Georgiev – Sqilline Health

Click here to read the full publication in Cancers (MDPI)