Penpulimab for Relapsed or Refractory Classical Hodgkin Lymphoma: A Multicenter, Single-Arm, Pivotal Phase I/II Trial (AK105-201)

Phase 1b/2 study of penpulimab (AK105), an antiprogrammed cell death-1 immunoglobulin G1 antibody, in advanced or metastatic solid tumors (AK105-204)

BACKGROUND

Penpulimab, a new-generation antiprogrammed cell death-1 immunoglobulin G1 monoclonal antibody, was engineered to optimize receptor occupancy and eliminate fragment crystallizable γ-mediated effector function. In this multicenter, phase 1b/2, multicohort study, the objective was to investigate the efficacy, safety, and immunogenicity of penpulimab in advanced solid tumors.

METHODS

Patients who had unresectable, advanced solid tumors were enrolled from six centers and received 200 mg penpulimab on day 1 every 2 weeks for up to 24 months. The primary end point was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors, version criteria 1.1.

RESULTS

Between September 2, 2019, and January 1, 2020, 65 patients were enrolled and received penpulimab. At the time of data cutoff (May 11, 2022), the median follow-up was 12.6 months (range, 1.1-28.6 months). The ORR was 12.3 (95% confidence interval [CI], 5.5%-22.8%), with three (4.6%) complete responses and five (7.7%) partial responses. Twelve patients (18.5%) achieved stable disease, resulting in a disease control rate of 30.8% (95% CI, 19.9%-43.4%). The median duration of response was not reached (95% CI, 6.70 months to not estimable). In all cohorts, the median progression-free survival was 1.74 months (95% CI, 1.41-2.69 months), and the median overall survival was 16.59 months (95% CI, 7.82-22.18 months). Grade 3 or greater treatment-related adverse events and immune-related adverse events occurred in 9.2% and 27.7% of patients, respectively. Positive antidrug antibody responses to penpulimab were observed in one patient (1.8%).

CONCLUSIONS

Penpulimab showed promising antitumor activity with an acceptable safety profile, offering a potential new treatment approach for solid tumors. These findings supported the evaluation of penpulimab's durable activity and safety, as monotherapy or in combination therapy, in specific malignancies.

Achilles' Heel of currently approved immune checkpoint inhibitors: immune related adverse events

Immunotherapy has revolutionized the cancer treatment landscape by opening up novel avenues for intervention. As the use of immune checkpoint inhibitors (ICIs) has exponentially increased, so have immune-related adverse events (irAEs). The mechanism of irAEs may involve the direct damage caused by monoclonal antibodies and a sequence of immune responses triggered by T cell activation. Common side effects include dermatologic toxicity, endocrine toxicity, gastrointestinal toxicity, and hepatic toxicity. While relatively rare, neurotoxicity, cardiotoxicity, and pulmonary toxicity can be fatal. These toxicities pose a clinical dilemma regarding treatment discontinuation since they can result in severe complications and necessitate frequent hospitalization. Vigilant monitoring of irAEs is vital in clinical practice, and the principal therapeutic strategy entails the administration of oral or intravenous glucocorticoids (GSCs). It may be necessary to temporarily or permanently discontinue the use of ICIs in severe cases. Given that irAEs can impact multiple organs and require diverse treatment approaches, the involvement of a multidisciplinary team of experts is imperative. This review aims to comprehensively examine the pathogenesis, clinical manifestations, incidence, and treatment options for various irAEs.

Hot and cold tumors: Immunological features and the therapeutic strategies

The "hotness" or "coldness" of the tumors are determined by the information of the cancer cells themselves, tumor immune characteristics, tumor microenvironment, and signaling mechanisms, which are key factors affecting cancer patients' clinical efficacy. The switch mechanism of "hotness" and "coldness" and its corresponding pathological characteristics and treatment strategies are the frontier and hot spot of tumor treatment. How to distinguish the "hotness" or "coldness" effectively and clarify the causes, microenvironment state, and characteristics are very important for the tumor response and efficacy treatments. Starting from the concept of hot and cold tumor, this review systematically summarized the molecular characteristics, influencing factors, and therapeutic strategies of "hot and cold tumors," and analyzed the immunophenotypes, the tumor microenvironment, the signaling pathways, and the molecular markers that contribute to "hot and cold tumors" in details. Different therapeutic strategies for "cold and hot tumors" based on clinical efficacy were analyzed with drug targets and proteins for "cold and hot tumors." Furthermore, this review combines the therapeutic strategies of different "hot and cold tumors" with traditional medicine and modern medicine, to provide a basis and guidance for clinical decision-making of cancer treatment.

Long-term survival benefit of anti-PD-1 therapy in patients with relapsed or refractory classical Hodgkin lymphoma

Anti-programmed cell death-1 (anti-PD-1) therapies have shown a favorable efficacy and good tolerance for relapsed or refractory (r/r) classical Hodgkin lymphoma (cHL). However, there are limited data on long-term outcomes among patients with r/r cHL who achieve an objective response to anti-PD-1 therapies. A total of 260 responders from four, phase 2 clinical trials were included in this study. The median age was 32 years with a male/female ratio of 1.3:1. After a median follow-up period of 31.1 months, 116 (44.6%) responders experienced disease progression and 18 (6.9%) died. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 55.1% and 89.7% overall. Patients with partial remission (PR) had inferior outcomes compared with those who achieved complete remission (3-year PFS, 29.5% vs. 72.3%, P < 0.001; 3-year OS, 81.5% vs. 94.4%, P = 0.017). Moreover, the survival outcome was inferior for patients with refractory disease compared with those with relapsed disease. Multivariate Cox regression analysis showed PR and refractory disease were independent risk factors for PFS. In conclusion, PR and refractory disease have a negative impact on the survival benefit of anti-PD-1 therapeutics in patients with r/r cHL, which highlights the need for multimodal treatment strategies.

Efficacy of Immune Checkpoint Blockade and Biomarkers of Response in Lymphoma: A Narrative Review

Immune checkpoint blockade (ICB) has revolutionized the prognosis of several advanced-stage solid tumors. However, its success has been far more limited in hematological malignancies and is mostly restricted to classical Hodgkin lymphoma (cHL) and primary mediastinal B cell lymphoma (PMBCL). In patients with non-Hodgkin lymphoma (NHL), response to PD-1/PD-L1 ICB monotherapy has been relatively limited, although some subtypes are more sensitive than others. Numerous predictive biomarkers have been investigated in solid malignancies, such as PD-L1 expression, tumor mutational burden (TMB) and microsatellite instability (MSI), among others. This review aims to appraise the current knowledge on PD-1/PD-L1 ICB efficacy in lymphoma when used either as monotherapy or combined with other agents, and describes potential biomarkers of response in this specific setting.

Filling the Gap: The Immune Therapeutic Armamentarium for Relapsed/Refractory Hodgkin Lymphoma

Despite years of clinical progress which made Hodgkin lymphoma (HL) one of the most curable malignancies with conventional chemotherapy, refractoriness and recurrence may still affect up to 20–30% of patients. The revolution brought by the advent of immunotherapy in all kinds of neoplastic disorders is more than evident in this disease because anti-CD30 antibodies and checkpoint inhibitors have been able to rescue patients previously remaining without therapeutic options. Autologous hematopoietic cell transplantation still represents a significant step in the treatment algorithm for chemosensitive HL; however, the possibility to induce complete responses after allogeneic transplant procedures in patients receiving reduced-intensity conditioning regimens informs on its sensitivity to immunological control. Furthermore, the investigational application of adoptive T cell transfer therapies paves the way for future indications in this setting. Here, we seek to provide a fresh and up-to-date overview of the new immunotherapeutic agents dominating the scene of relapsed/refractory HL. In this optic, we will also review all the potential molecular mechanisms of tumor resistance, theoretically responsible for treatment failures, and we will discuss the place of allogeneic stem cell transplantation in the era of novel therapies.