Pune, India | October 07, 2025
The U.S. Food and Drug Administration (FDA) has approved a combination of lurbinectedin (Zepzelca) with atezolizumab (Tecentriq) or atezolizumab and hyaluronidase-tqjs (Tecentriq Hybryza) as maintenance therapy for adults with extensive-stage small cell lung cancer (ES-SCLC).
This approval is aimed at patients whose cancer has not progressed after initial treatment with atezolizumab, carboplatin, and etoposide, marking a notable advancement in managing an aggressive and fast-growing cancer. Traditionally, treatment options for ES-SCLC after first-line chemotherapy are scarce, and relapse is common. By introducing a maintenance therapy option, the FDA offers oncologists a new tool to prolong remission and improve patient outcomes.
This decision is based on data from the IMforte clinical trial, a randomized, open-label, multicenter Phase 3 study involving 483 ES-SCLC patients who had completed four cycles of induction therapy. Participants were randomly assigned to either lurbinectedin plus atezolizumab or atezolizumab alone, continuing treatment until disease progression or unacceptable toxicity.
Results revealed a clear survival advantage in the combination group. Median overall survival reached 13.2 months compared to 10.6 months for atezolizumab alone. Progression-free survival was 5.4 months in the combination group versus 2.1 months in the monotherapy group, underscoring the therapy’s capacity to delay disease worsening.
Furthermore, statistical analysis confirmed these benefits. The hazard ratio for overall survival stood at 0.73, and for progression-free survival at 0.54, both favoring combination therapy. P-values of 0.0174 and less than 0.0001 suggest that these results are unlikely to be due to chance, affirming the treatment’s efficacy. Patients with ES-SCLC often measure progress in weeks, so this improvement adds meaningful time for both survival and quality of life.
However, the therapies come with significant risks. Lurbinectedin carries warnings for myelosuppression, hepatotoxicity, tissue injury from infusion leaks, rhabdomyolysis, and embryo-fetal toxicity. Similarly, atezolizumab and its hyaluronidase-tqjs formulation can cause severe immune-related events, infusion complications, and issues in patients undergoing bone marrow transplants. Consequently, healthcare providers must closely monitor patients, discuss potential side effects, and act promptly if adverse reactions occur.
The approved dosing schedules add flexibility to patient management. Lurbinectedin is administered at 3.2 mg/m² via intravenous infusion every 21 days. Atezolizumab dosing varies between every two, three, or four weeks, based on the prescribed amount. In its subcutaneous formulation with hyaluronidase-tqjs, atezolizumab is given as 1875 mg combined with 30,000 units of hyaluronidase every three weeks, providing an alternative delivery method that may suit specific patients.
Notably, this approval falls under the FDA’s Project Orbis program, designed to accelerate access to promising oncology drugs through simultaneous international regulatory reviews. In this initiative, the FDA collaborated with authorities in Australia, Canada, Israel, and Switzerland, aiming to fast-track global availability of therapies for cancers with limited options. Both lurbinectedin and atezolizumab have received orphan drug designation, reflecting their importance for treating a rare and severe disease. Additionally, the review was prioritized and aided by the FDA’s Assessment Aid tool, which helps streamline decision-making by organizing critical trial data.
Clinicians must consider individual patient factors when prescribing this regimen. Not all patients will respond identically, and tolerability varies. Thorough patient selection and ongoing monitoring will be vital to achieve optimal benefit while minimizing risks. Furthermore, as these drugs enter broader use, post-market surveillance will help refine safety profiles and enhance pharmacovigilance. Healthcare professionals are urged to report serious adverse events to the FDA’s MedWatch program, assisting in identifying potential safety signals early.
In a disease where frequent relapse hampers progress, this dual-agent maintenance approach stands out as a welcome shift in the therapeutic landscape for ES-SCLC. It reflects a movement toward more tailored, prolonged intervention beyond initial chemotherapy, offering hope for longer survival and improved day-to-day living.
As additional research unfolds, protocols will likely evolve, revealing which patient subgroups gain the most from adding lurbinectedin to atezolizumab. For now, this approval represents a meaningful step forward in a long-challenging cancer battle, broadening the arsenal for both physicians and patients confronted with this formidable disease.
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