Low-Dose Nivolumab Improves Survival in Relapsed/Refractory Solid Tumors

A new study out of India is challenging conventional wisdom regarding immunotherapy dosing for solid tumors. Researchers at Tata Memorial Hospital in Mumbai have found that “ultra-low-dose” nivolumab, an immune checkpoint inhibitor, demonstrated improved overall survival compared to standard chemotherapy in patients with relapsed or refractory cancers, while also exhibiting a more favorable toxicity profile.

The findings, published in the Journal of Clinical Oncology, stem from the DELII trial, an open-label, phase III study involving 500 patients. Participants, all of whom had experienced disease progression after at least one prior line of systemic therapy, were randomized to receive either 20mg of nivolumab every two weeks or traditional chemotherapy – docetaxel or paclitaxel, selected based on their specific cancer type.

The patient cohort was heavily weighted towards those with head and neck cancer (52%) and lung cancer (36%). A significant proportion, 53%, presented with metastatic disease. The median number of prior therapies received was one, though nearly a third (29%) had undergone two or more previous treatment regimens. This speaks to the advanced stage of illness among the study participants, highlighting the urgent need for effective treatment options.

The results revealed a statistically significant improvement in overall survival for the nivolumab group. Median overall survival reached 5.88 months, compared to 4.70 months in the chemotherapy arm (hazard ratio [HR] = 0.80, 95% confidence interval [CI] = 0.66–0.97, P = .022). At the one-year mark, 27.3% of patients receiving nivolumab were still alive, versus 16.9% in the chemotherapy group. The benefit appeared consistent across cancer types, with hazard ratios of 0.86 for head and neck cancer patients and 0.77 for those with other cancers.

Interestingly, while overall survival improved, progression-free survival did not show a statistically significant difference between the two groups. The median progression-free survival was 2.04 months for nivolumab and 2.09 months for chemotherapy (HR = 1.03, 95% CI = 0.86–1.23, P = .77). This suggests that while the low-dose nivolumab didn’t necessarily halt tumor growth for a longer period, it did offer a survival advantage, potentially by extending life even with disease progression.

Perhaps one of the most compelling aspects of the study is the observed difference in toxicity. Grade ≥ 3 treatment-related adverse events occurred in 42.5% of patients in the nivolumab group, significantly lower than the 60.8% seen in the chemotherapy group (P &lt. .001). Hyponatremia (low sodium levels) was the most common severe adverse event in both groups, occurring in 28.6% of the nivolumab patients and 40.5% of those on chemotherapy. The study also noted improvements in global health status over time in both groups, but the trajectory was demonstrably better for those receiving the lower dose of nivolumab (P = .014).

These findings have potentially far-reaching implications for cancer treatment strategies. The investigators, led by

Kumar Prabhash, DM, MD, MBBS

, concluded that ultra–low-dose nivolumab “significantly improves [overall survival] vs chemotherapy in pretreated solid tumors, with fewer severe toxicities and better [quality of life].” They advocate for a re-evaluation of current immune checkpoint inhibitor dosing strategies, suggesting that lower doses could offer a more favorable balance of efficacy and safety, and crucially, could enhance global access to these vital therapies.

The concept of dose optimization is gaining traction within the oncology community. Traditionally, immunotherapy has been administered at higher doses, often leading to significant side effects and limiting accessibility, particularly in resource-constrained settings. This study suggests that a lower dose may be equally, or even more, effective while minimizing toxicity and potentially reducing costs. This is particularly relevant given the increasing financial burden of cancer care globally.

The DELII trial was funded by the R. G. Manudhane Foundation for Excellence, the Trilokchand Papriwal Trust, and Tata Memorial Hospital. The research team emphasizes the importance of further investigation to confirm these findings in larger, more diverse patient populations and to identify biomarkers that could predict which patients are most likely to benefit from this ultra-low-dose approach. The study opens a new avenue for exploration in the ongoing quest to improve outcomes for patients battling relapsed or refractory solid tumors.