The Development of STING Agonists and Emerging Results as a Cancer Immunotherapy.

PURPOSE OF REVIEW: New therapies are needed to potentiate the effects of current immunotherapies and overcome resistance. The stimulator of interferon genes genes (STING) pathway is an innate immune activating cascade that may enhance current cancer immunotherapies. RECENT FINDINGS: Preclinical data has shown that the addition of a STING agonist enhances the effect of current treatments such as immune checkpoint inhibitor antibodies and radiation therapy. Early phase trials have demonstrated modest efficacy of STING agonists and revealed new mechanistic and technical challenges. STING agonists are a new class of agents that activate the immune response to improve tumor control. A wide range of preclinical experiments, translational data, and ongoing clinical trials support the therapeutic use of STING agonists in patients. Trials to determine optimal drug combinations and novel delivery mechanisms are continuing in development.

Targeted Toxicities: Protocols for Monitoring the Adverse Events of Targeted Therapies Used in the Treatment of Non-Small Cell Lung Cancer.

Targeted therapies have revolutionized the treatment for many patients with non-small cell lung cancer (NSCLC). Multiple new oral targeted therapies have been approved in the last decade; however, their overall efficacy may be reduced by poor adherence, treatment interruptions, or dose reductions due to adverse events. Most institutions lack standard monitoring protocols for toxicities from these targeted agents. This review describes important adverse events observed in clinical trials and reported by the U.S. Food and Drug Administration for both currently approved and upcoming promising therapies in the treatment of NSCLC. These agents cause a range of toxicities, including dermatologic, gastroenteric, pulmonary, and cardiac toxicities. This review proposes protocols for routine monitoring of these adverse events, both prior to initiation of therapy and while on treatment.

Studying Outcomes after Steroid-Sparing Immunosuppressive Agent vs. Steroid-Only Treatment for Immune-Related Adverse Events in Non-Small-Cell Lung Cancer (NSCLC) and Melanoma: A Retrospective Case-Control Study.

BACKGROUND: The effects of steroid-sparing immunosuppressive agents (SSIAs), used for the treatment of immune-related adverse events (irAEs), on immune checkpoint inhibitor (ICI) antitumor activity is not well known. We compared tumor outcomes of patients who received corticosteroid monotherapy (CS) versus a corticosteroid plus SSIA (CS-SSIA) for irAE treatment, using statistical methods to address immortal time bias. METHODS: We conducted a retrospective case-control study on patients ≥ 18 years with melanoma or non-small-cell lung cancer (NSCLC) treated with ≥1 ICI at a quaternary care center between 1 January 2016 and 11 January 2021. Patients were divided into two cohorts: CS or CS-SSIA. We used propensity score nearest-neighbor matching to match on tumor type, stage, and prior lines of therapy. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Secondary outcomes included the time from the start of the irAE treatment to the irAE resolution. Hazard ratios (HRs) for PFS and OS were calculated using the Cox proportional hazard regression method with both (1) the time to the steroid and SSIA as time-varying covariates and (2) a binary exposure classification not accounting for the time to the treatment. RESULTS: A total of 167 patients were included after matching (132 in the CS cohort and 35 in the CS-SSIA cohort). Sixty-six percent of all the patients had melanoma. The most common irAEs requiring treatment were gastroenterocolitis and hepatitis. In an adjusted analysis not accounting for immortal time bias, there were no significant differences in PFS (HR 0.75, 95% CI [0.46-1.23]) or OS (HR 0.82, 95% CI [0.46-1.47]). In analyses using a time-varying treatment indicator, there was a trend toward improved PFS in patients treated with SSIAs (HR 0.54, CI 0.26-1.10). There was no difference in OS (HR 1.11, CI 0.55-2.23). Patients with melanoma who specifically received infliximab had improved PFS compared to patients with CS only, after adjusting for immortal time bias (HR 0.32, CI 0.24-0.43). CONCLUSIONS: The use of SSIAs with CS did not have worse outcomes than CS monotherapy. In melanoma, our findings showed improved PFS for the use of infliximab versus steroid monotherapy for irAEs. Large, prospective, randomized controlled trials are needed to confirm these findings and guide the optimal treatment of irAEs.

Evaluation of Major Pathologic Response and Pathologic Complete Response as Surrogate End Points for Survival in Randomized Controlled Trials of Neoadjuvant Immune Checkpoint Blockade in Resectable in NSCLC.

INTRODUCTION: Controversy remains as to whether pathologic complete response (pCR) and major pathologic response (MPR) represent surrogate end points for event-free survival (EFS) and overall survival (OS) in neoadjuvant trials for resectable NSCLC. METHODS: A search of PubMed and archives of international conference abstracts was performed from June 2017 through October 31, 2023. Studies incorporating a neoadjuvant arm with immune checkpoint blockade alone or in combination with chemotherapy were included. Those not providing information regarding pCR, MPR, EFS, or OS were excluded. For trial-level surrogacy, log ORs for pCR and MPR and log hazard ratios for EFS and OS were analyzed using a linear regression model weighted by sample size. The regression coefficient and R2 with 95% confidence interval were calculated by the bootstrapping approach. RESULTS: Seven randomized clinical trials were identified for a total of 2385 patients. At the patient level, the R2 of pCR and MPR with 2-year EFS were 0.82 (0.66-0.94) and 0.81 (0.63-0.93), respectively. The OR of 2-year EFS rates by response status was 0.12 (0.07-0.19) and 0.11 (0.05-0.22), respectively. For the 2-year OS, the R2 of pCR and MPR were 0.55 (0.09-0.98) and 0.52 (0.10-0.96), respectively. At the trial level, the R2 for the association of OR for response and HR for EFS was 0.58 (0.00-0.97) and 0.61 (0.00-0.97), respectively. CONCLUSIONS: Our analyses reveal a robust correlation between pCR and MPR with 2-year EFS but not OS. Trial-level surrogacy was moderate but imprecise. More mature follow-up and data to assess the impact of study crossover are needed.

What is the ideal endpoint in early-stage immunotherapy neoadjuvant trials in lung cancer?

Numerous clinical trials investigating neoadjuvant immune checkpoint inhibitors (ICI) have been performed over the last 5 years. As the number of neoadjuvant trials increases, attention must be paid to identifying informative trial endpoints. Complete pathologic response has been shown to be an appropriate surrogate endpoint for clinical outcomes, such as event-free survival or overall survival, in breast cancer and bladder cancer, but it is less established for non-small-cell lung cancer (NSCLC). The simultaneous advances reported with adjuvant ICI make the optimal strategy for early-stage disease debatable. Considering the long time required to conduct trials, it is important to identify optimal endpoints and discover surrogate endpoints for survival that can help guide ongoing clinical research. Endpoints can be grouped into two categories: medical and surgical. Medical endpoints are measures of survival and drug activity; surgical endpoints describe the feasibility of neoadjuvant approaches at a surgical level as well as perioperative attrition and complications. There are also several exploratory endpoints, including circulating tumor DNA clearance and radiomics. In this review, we outline the advantages and disadvantages of commonly reported endpoints for clinical trials of neoadjuvant regimens in NSCLC.

Systematic review and meta-analysis of immune checkpoint inhibitors as single agent or in combination with chemotherapy in early-stage non-small cell lung cancer: Impact of clinicopathological factors and indirect comparison between treatment strategies.

BACKGROUND: In non-small cell lung cancer (NSCLC), the immune checkpoint inhibitors (ICI) revolution is rapidly moving from metastatic to early-stage, however, the impact of clinicopathological variables and optimal treatment sequencing remain unclear. METHODS: Randomized controlled trials (RCTs) in patients with early-stage NSCLC treated with ICI as single agent or in combination with platinum-based chemotherapy (PCT) were included. Primary outcomes were pathological complete response (pCR), event free survival (EFS) (neoadjuvant/perioperative), and disease-free survival (DFS) (adjuvant). Secondary outcomes were major pathological response (MPR), overall survival (OS), toxicity, surgical outcomes (neoadjuvant/perioperative); OS and toxicity (adjuvant). An additional secondary endpoint was to compare EFS and OS between neoadjuvant and perioperative strategies. RESULTS: 8 RCTs (2 neoadjuvant, 4 perioperative, 2 adjuvant) (4661 participants) were included. Neoadjuvant/perioperative ICI+PCT significantly improved pCR, EFS, OS, MPR and R0 resection compared to PCT. Adjuvant ICI significantly improved DFS compared to placebo. There was a significant subgroup interaction by PD-L1 status (χ2 = 10.72, P = 0.005), pCR (χ2 = 17.80, P < 0.0001), and stage (χ2 = 4.46, P = 0.003) for EFS. No difference according to PD-L1 status was found for pCR, with 14% of patients having PD-L1 negative tumors still experiencing a pCR. No interaction by PD-L1 status was found for DFS upon adjuvant ICI. Indirect comparison showed no difference in EFS and OS between neoadjuvant and perioperative ICI+PCT. CONCLUSIONS: PD-L1 status, pCR and stage impact on survival upon neoadjuvant/perioperative ICI. The restriction of neoadjuvant/perioperative ICI to PD-L1 + patients could preclude pCR and long-term benefit in the PD-L1- subgroup. Neoadjuvant and perioperative could be equivalent strategies.

Comutations and KRASG12C Inhibitor Efficacy in Advanced NSCLC.

Molecular modifiers of KRASG12C inhibitor (KRASG12Ci) efficacy in advanced KRASG12C-mutant NSCLC are poorly defined. In a large unbiased clinicogenomic analysis of 424 patients with non-small cell lung cancer (NSCLC), we identified and validated coalterations in KEAP1, SMARCA4, and CDKN2A as major independent determinants of inferior clinical outcomes with KRASG12Ci monotherapy. Collectively, comutations in these three tumor suppressor genes segregated patients into distinct prognostic subgroups and captured ∼50% of those with early disease progression (progression-free survival ≤3 months) with KRASG12Ci. Pathway-level integration of less prevalent coalterations in functionally related genes nominated PI3K/AKT/MTOR pathway and additional baseline RAS gene alterations, including amplifications, as candidate drivers of inferior outcomes with KRASG12Ci, and revealed a possible association between defective DNA damage response/repair and improved KRASG12Ci efficacy. Our findings propose a framework for patient stratification and clinical outcome prediction in KRASG12C-mutant NSCLC that can inform rational selection and appropriate tailoring of emerging combination therapies. SIGNIFICANCE: In this work, we identify co-occurring genomic alterations in KEAP1, SMARCA4, and CDKN2A as independent determinants of poor clinical outcomes with KRASG12Ci monotherapy in advanced NSCLC, and we propose a framework for patient stratification and treatment personalization based on the comutational status of individual tumors. See related commentary by Heng et al., p. 1513. This article is highlighted in the In This Issue feature, p. 1501.

Steroid-refractory dermatologic and pulmonary toxicity in a patient on rituximab treated with pembrolizumab for progressive urothelial carcinoma: a case report.

BACKGROUND: Increasingly widespread use of programmed cell death protein 1 (PD-1) immune checkpoint inhibitors (ICIs) for treatment of a variety of progressive malignancies continues to reveal a range of immune-related adverse events (irAEs), necessitating immunosuppressive therapy for management. While a single course of systemic corticosteroids may be sufficient for many irAEs, no clear standard-of-care guidelines exist for steroid-refractory cases. We present an unusual case of a patient who developed several steroid-refractory novel irAEs on pembrolizumab despite ongoing B cell-directed immunosuppressive therapy with rituximab, who ultimately noted resolution of symptoms with tacrolimus, a T-cell-directed immunosuppressant. CASE PRESENTATION: This 72-year-old Caucasian man with Waldenstrom's macroglobulinemia and myelin-associated glycoprotein (MAG) immunoglobulin M (IgM) antibody-associated neuropathy was being treated with maintenance rituximab and intravenous immunoglobulin when he was started on pembrolizumab (2.26 mg/kg) for metastatic urothelial cancer 31 months after surgery and adjuvant chemotherapy. After his third dose of pembrolizumab, he developed a painful blistering papular rash of the distal extremities. He received two more doses of pembrolizumab before he also developed diarrhea, and it was held; he was initiated on 1 mg/kg prednisone for presumed ICI-induced dermatitis and colitis. Skin biopsy 10 weeks after cessation of pembrolizumab and taper of steroids to 20  mg daily revealed a unique bullous erythema multiforme. He was then admitted with dyspnea and imaging concerning for necrotizing pneumonia, but did not respond to antibiotic therapy. Bronchoscopy and biopsy revealed acute fibrinous organizing pneumonia. His symptoms failed to fully respond to multiple courses of high-dose systemic corticosteroids and a trial of azathioprine, but pneumonia, diarrhea, and skin rash all improved markedly with tacrolimus. The patient has since completed his therapy for tacrolimus, continues off of ICI, and has not experienced a recurrence of any irAEs, though has more recently experienced progression of his cancer. CONCLUSION: Despite immunosuppression with rituximab and intravenous immunoglobulin, two immunomodulators targeting B cells, ICI cessation, and systemic corticosteroid therapy, our patient developed two high-grade unusual irAEs, bullous erythema multiforme and acute fibrinous organizing pneumonia. Our patient's improvement with tacrolimus can offer critical insight into the pathophysiology of steroid-refractory irAEs.