The POLARGO trial has revealed that polatuzumab vedotin combined with rituximab, gemcitabine, and oxaliplatin (Pola-R-GemOx) significantly improves overall survival for patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who are ineligible for stem cell transplant. According to final results published in the Journal of Clinical Oncology, median overall survival reached 19.5 months with Pola-R-GemOx compared to 12.5 months with the standard regimen of rituximab, gemcitabine, and oxaliplatin (R-GemOx).
An Unmet Need in Transplant-Ineligible DLBCL
Patients with R/R DLBCL who cannot undergo stem cell transplantation have historically faced limited treatment options after initial therapy fails. While high-dose chemotherapy with autologous stem cell transplant was once standard, many patients are excluded due to age, comorbidities, or poor response to salvage therapy. Chimeric antigen receptor (CAR) T-cell therapy has since become a preferred option for some, though cost and access constraints remain barriers. The POLARGO trial aimed to expand options by evaluating polatuzumab vedotin paired with gemcitabine and oxaliplatin, building on its prior approval in first-line DLBCL when combined with bendamustine and rituximab.
The phase 3, randomized POLARGO trial enrolled 255 adults with transplant-ineligible R/R DLBCL across 64 sites in 16 countries. After an initial safety run-in of 15 patients, participants were randomly assigned 1:1 to receive Pola-R-GemOx or R-GemOx every 21 days for up to 8 cycles. All patients had received at least one prior line of therapy, with randomization stratified by age, prior treatment lines, and refractory status. The primary endpoint was overall survival, with secondary endpoints including progression-free survival (PFS), complete response (CR) rate, and overall response rate (ORR).
Survival and Response Benefits With Pola-R-GemOx
After a median follow-up of 24.6 months, Pola-R-GemOx reduced the risk of death by 40% compared to R-GemOx (hazard ratio [HR], 0.60; 95% CI, 0.43-0.83; P = .0017), meeting the primary endpoint. The median OS was 19.5 months (95% CI, 13.3-not estimable) for Pola-R-GemOx versus 12.5 months (95% CI, 8.9-15.8) for R-GemOx. At 24 months, the survival rate improved from 33.2% to 44.0% with the polatuzumab-based regimen.
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Secondary outcomes also favored Pola-R-GemOx. The risk of progression or death decreased by 63% (HR, 0.37; 95% CI, 0.27-0.51; P < .0001), with median PFS extending from 2.7 to 7.4 months. The complete response rate more than doubled, rising from 19.0% to 40.3%, while the overall response rate increased from 24.6% to 52.7%. These benefits were consistent across subgroups, including patients with activated B-cell-like and germinal center B-cell-like disease subtypes.
“The POLARGO study establishes Pola-R-GemOx as an effective and tolerable treatment option for patients with transplant-ineligible R/R DLBCL, significantly improving OS and CR rates and representing a valuable, non-lymphodepleting addition to current treatment options,” the authors wrote.
Earlier Conference Presentation Lacked Full Data Set
A presentation of the POLARGO trial at the European Hematology Association’s 2025 congress prompted earlier coverage citing a hazard ratio of 0.6 for overall survival. That presentation lacked the median overall survival, progression-free survival, and safety figures now available in the peer-reviewed publication, offering a fuller picture than the conference talk could.
Median age was 65 years, with most patients having an Eastern Cooperative Oncology Group performance status of 0 or 1. Stage III/IV disease was present in 76.5% of participants, and nearly two-thirds had received only one prior line of therapy. Disease refractory to the most recent treatment occurred in 65.9% of cases.
Safety and Tolerability
Common grade 3/4 adverse events in both arms included thrombocytopenia and neutropenia. Peripheral neuropathy occurred more frequently with Pola-R-GemOx (57.0% vs 28.8%) than with the comparator regimen, though most cases were grade 1, and only 2.3% discontinued polatuzumab vedotin due to this toxicity. The GemOx backbone maintained its dose intensity despite the addition of the antibody-drug conjugate.
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Fatal adverse events were more common with Pola-R-GemOx (12% vs 4%), primarily driven by infections, including COVID-19 (5.5% of fatal events in the Pola-R-GemOx group vs 1.6% in the control arm). Treatment discontinuation due to toxicity was higher in the Pola-R-GemOx group (23.4% vs 8.0%), most often because of infections or thrombocytopenia.
Limitations and Clinical Implications
The authors noted that POLARGO was designed before CAR T-cell therapy received approval for second-line use and before polatuzumab vedotin entered first-line treatment. Consequently, the trial does not address how Pola-R-GemOx performs in patients previously exposed to the agent earlier in their care. Additionally, R-GemOx, the comparator arm, is increasingly viewed as an outdated standard, and differences in baseline characteristics across similar trials complicate cross-study comparisons.
Even with these caveats, the mature survival data provide a stronger basis for decision-making in transplant-ineligible R/R DLBCL patients. For clinicians considering bridging therapy before potentially curative cellular treatments and payers evaluating a four-drug regimen against newer bispecific combinations, these results offer a clearer framework for treatment selection in a population with historically limited durable options.
Limits of cross-trial comparisons persist, and ongoing studies will clarify Pola-R-GemOx’s role in earlier lines of therapy. For now, the results represent a meaningful step forward for a patient group long underserved by available treatments.