Long-term efficacy and safety of chemotherapy-free first-line iodine-131-rituximab radioimmunotherapy of follicular lymphoma

Bifunctional molecular probe targeting tumor PD-L1 enhances anti-tumor efficacy by promoting ferroptosis in lung cancer mouse model

PURPOSE

Immune checkpoint inhibitors (ICIs) targeting tumor-specific PD-1/PD-L1 significantly improve the overall survival rate of patients with advanced cancer by reactivating the immune system to attack cancer cells. To explore their tumor killing effect, we used the radionuclide iodine-131 (131I) to label the anti-PD-L1 antibody Atezolizumab (131I-PD-L1 mAb).

METHOD

We prepared the radioimmunoassay molecular probe 131I-PD-L1 mAb by the chloramine-T method and evaluated its affinity using Lewis lung cancer (LLC) cells. The uptake of 131I-PD-L1 mAb by transplanted tumors was examined through SPECT and its in vivo distribution. We then compared the in vitro and in vivo anti-tumor efficacy of groups treated with control, PD-L1 mAb, 131I-PD-L1 mAb, and 131I-PD-L1 mAb + PD-L1 mAb combined treatment. We performed H&E staining to examine the changes in tumor, as well as the damage in major tissues and organs caused by potential side effects. The anti-tumor mechanism of 131I-PD-L1 mAb was analyzed by Western blot, RT-qPCR and immunohistochemistry (IHC).

RESULT

131I-PD-L1 mAb was highly stable and specific, and easily penetrated into tumor. 131I-PD-L1 mAb suppressed cancer cell proliferation in vitro, and inhibited tumor growth in vivo by inducing ferroptosis, thus prolonging the survival of experimental animals while demonstrating biological safety.

CONCLUSION

Therefore, our study suggested that 131I-PD-L1 mAb affected the expression of tumor-related factors through β-rays and thus promoted ferroptosis in tumor. Combined treatment showed better anti-tumor effect compared to single ICI treatment.

Theranostic Innovation by Humane N-of-One Cancer Care in Real-World Patients

Patients with relapsed or refractory metastatic cancer unresponsive to standard therapies have motivated nuclear physicians to develop innovative radioligands, precisely targeted to tumor molecular receptors, for effective treatment of specific advanced malignancies. Individual practitioners in departments of nuclear medicine across the world have performed first-in-human studies on compassionate patient usage N-of-One protocols. These physician-sponsored studies then evolved into early-phase clinical trials and obtained real-world data to demonstrate real-world evidence of effectiveness in prolonging survival and enhancing quality of life of many so-called "End-Stage" cancer patients. Virtually all the therapeutic radiopharmaceuticals in current clinical oncology have been discovered and developed into effective specific treatments of targetable cancers by individual doctors in the course of their hospital practice. Pharma industry was not involved until many years later when performance of mandated Phase 3 randomized controlled trials became necessary to achieve regulatory agency approval. This article traces the history of several novel theranostic agents developed from compassionate N-of-One studies by hospital physicians over the past 36 years. It acknowledges the collegiality and collaboration of individual nuclear medicine specialists, worldwide, in pioneering effective humane therapy of particular advanced cancers unresponsive to conventional treatments.

Philosophy of Cancer Theranostics

Imagine a theranostic nuclear physician oncologist engaged in a Socratic philosophic dialogue. Questions that may be posed include the status of our current knowledge base of radiomolecular tumor biology, the meaning of precision in personalized dosimetry, the nature of responsibility for direct patient care, and the moral and ethical dimensions of individual quality of life (QOL) when survival is prolonged. This review invites reflective enquiry into one's personal practice of theranostics in cancer care, with the objective of optimizing clinical outcomes, not only in terms of prolonged survival but also individual QOL, in respect of its meaning for each patient, both physically and emotionally.

Life-Saving Cancer Care

What, precisely, are we seeking to achieve in offering 'life-saving' treatment to patients with cancer? Research funding agencies and pharmaceutical industry media releases, and government cancer screening programs all promise that their cancer programs save lives. But everybody dies. The nature of life and death from cancer is explored philosophically in this essay, with particular reference to the quality of life, and its meaning, during the period of prolongation of survival by 'life-saving' cancer care.