Association between immune-mediated adverse events and efficacy in metastatic non-small-cell lung cancer patients treated with durvalumab and tremelimumab.

Purpose: Immune-mediated adverse events (imAEs) may be associated with response to immune checkpoint inhibitors. We assessed the relationship between imAE development and efficacy in metastatic non-small-cell lung cancer patients treated with durvalumab (anti-programmed cell death ligand-1 [PD-L1]) alone or in combination with tremelimumab (anti-cytotoxic T-lymphocyte-associated protein 4). Methods: The analysis used individual patient-level data from 307 and 310 patients in the monotherapy and combination arms of MYSTIC, respectively. We evaluated the association between treatment efficacy and development of imAEs using univariate and multivariate survival analyses. Using machine learning, we built a predictive model utilizing baseline clinical and laboratory features to identify patients at risk of developing imAEs and further evaluated patient survival based on a threshold index extracted from the model. Results: Patients who developed any grade of imAE had improved overall survival versus patients without (hazard ratio [HR] 0.51; 95% confidence interval [CI]: 0.41-0.62). imAE development was associated with improved overall survival (HR 0.54; 95% CI 0.44-0.66) in a multivariate Cox proportional hazard model considering patient demographic features and baseline characteristics. Higher odds of imAE development were observed (odds ratio 3.023; 95% CI: 1.56-5.83) in responders versus non-responders in patients treated with immunotherapy. Based on baseline characteristics, the random forest classification algorithm was used to formulate a predictive model to identify patients at increased risk of developing imAEs during treatment. Conclusion: Post-hoc exploratory analysis found that the efficacy of immunotherapy was improved in patients who developed on-treatment imAEs. This was independent of severity of imAEs or the need for steroid treatment, which is important in allowing patients to remain on treatment and derive optimal clinical benefit. Further research is warranted to establish the correlation between incidence of imAEs and efficacy in this patient population.

Durvalumab After Sequential Chemoradiotherapy in Stage III, Unresectable NSCLC: The Phase 2 PACIFIC-6 Trial.

INTRODUCTION: On the basis of the findings of the phase 3 PACIFIC trial (NCT02125461), durvalumab is standard of care for patients with stage III, unresectable NSCLC and no disease progression after concurrent chemoradiotherapy (cCRT). Many patients are considered unsuitable for cCRT owing to concerns with tolerability. The phase 2 PACIFIC-6 trial (NCT03693300) evaluates the safety and tolerability of durvalumab after sequential CRT (sCRT). METHODS: Patients with stage III, unresectable NSCLC and no progression after platinum-based sCRT were enrolled to receive durvalumab (1500 mg intravenously) every 4 weeks for up to 24 months. The primary end point was the incidence of grade 3 or 4 adverse events possibly related to treatment occurring within 6 months. Secondary end points included investigator-assessed progression-free survival (PFS; Response Evaluation Criteria in Solid Tumors version 1.1) and overall survival. RESULTS: Overall, 117 patients were enrolled (59.8% with performance status >0, 65.8% aged ≥65 y, and 37.6% with stage IIIA disease). Median treatment duration was 32.0 weeks; 37.6% of patients remained on treatment at data cutoff (July 15, 2021). Grade 3 or 4 AEs occurred in 18.8% of patients. Five patients had grade 3 or 4 possibly related adverse events within 6 months (incidence: 4.3%; 95% confidence interval: 1.4-9.7), including two pneumonitis cases. Two patients (1.7%) had grade 5 AEs of any cause. Survival data maturity was limited. Median PFS was 10.9 months (95% confidence interval: 7.3-15.6), and 12-month PFS and overall survival rates were 49.6% and 84.1%, respectively. CONCLUSIONS: Durvalumab after sCRT had a comparable safety profile with that observed with durvalumab after cCRT in PACIFIC and had encouraging preliminary efficacy in a frailer population.

nab-paclitaxel/carboplatin induction in squamous NSCLC: longitudinal quality of life while on chemotherapy.

BACKGROUND: Longitudinal data on the impact of treatment on quality of life (QoL) in advanced non-small cell lung cancer (NSCLC) are limited. In this palliative setting, treatment that does not deteriorate QoL is key. Here we report longitudinal QoL in patients with squamous NSCLC, receiving ≤4 cycles of nab-paclitaxel/carboplatin combination chemotherapy. METHODS: Patients received nab-paclitaxel 100 mg/m2 days 1, 8, 15 + carboplatin area under the curve 6 mg•min/mL day 1 (q3w) for four cycles. QoL was assessed by the Lung Cancer Symptom Scale (LCSS) and Euro-QoL-5 Dimensions-5 Levels (EQ-5D-5L) at baseline and each cycle (day 1). RESULTS: Two-hundred and six lesion-response-evaluable patients completed baseline + ≥1 postbaseline QoL assessment and were QoL evaluable. LCSS average total score and symptom burden index improved from baseline throughout four cycles. In the LCSS pulmonary symptoms score, 46% of patients reported clinically meaningful improvement (≥10 mm visual analog scale) from baseline. Individual EQ-5D-5L dimensions remained stable/improved in ≥83% of patients; ≈33% reported complete resolution of baseline problems at least once during four cycles. Generally, responders (unconfirmed complete/partial response) had higher scores vs nonresponders. CONCLUSION: In patients with squamous NSCLC, four cycles of nab-paclitaxel/carboplatin demonstrated clinically meaningful QoL improvements, with greater benefits in responders vs nonresponders.

Delay of simian human immunodeficiency virus infection and control of viral replication in vaccinated macaques challenged in the presence of a topical microbicide.

OBJECTIVE: Development of an effective vaccine or topical compound to prevent HIV transmission remains a major goal for control of the AIDS pandemic. Using a nonhuman primate model of heterosexual HIV-1 transmission, we tested whether a topical microbicide that reduces viral infectivity can potentiate the efficacy of a T-cell-based HIV vaccine. DESIGN: A DNA prime and rAd5 virus boost vaccination strategy was employed, and a topical microbicide against the HIV nucleocapsid protein was used. To rigorously test the combination hypothesis, the vaccine constructs contained only two transgenes and the topical microbicide inhibitor was used at a suboptimal dose. Vaccinees were exposed in the absence and presence of the topical microbicide to repeated vaginal R5 simian human immunodeficiency virus (SHIV)(SF162P3) challenge at an escalating dose to more closely mimic high-risk exposure of women to HIV. METHODS: Infection status was determined by PCR. Antiviral immune responses were evaluated by gp120 ELISA and intracellular cytokine staining. RESULTS: A significant delay in SHIV acquisition (log-rank test; P = 0.0416) was seen only in vaccinated macaques that were repeatedly challenged in the presence of the topical microbicide. Peak acute viremia was lower (Mann-Whitney test; P = 0.0387) and viral burden was also reduced (Mann-Whitney test; P = 0.0252) in the combination-treated animals. CONCLUSION: The combined use of a topical microbicide to lower the initial viral seeding/spread and a T-cell-based vaccine to immunologically contain the early virological events of mucosal transmission holds promise as a preventive approach to control the spread of the AIDS epidemic.

Different mutational pathways to CXCR4 coreceptor switch of CCR5-using simian-human immunodeficiency virus.

We report here a second case of coreceptor switch in R5 simian-human immunodeficiency virus SF162P3N (SHIV(SF162P3N))-infected macaque CA28, supporting the use of this experimental system to examine factors that drive the change in coreceptor preference in vivo. Virus recovered from CA28 plasma (SHIV(CA28NP)) used both CCR5 and CXCR4 for entry, but the virus recovered from lymph node (SHIV(CA28NL)) used CXCR4 almost exclusively. Sequence and functional analyses showed that mutations in the V3 loop that conferred CXCR4 usage in macaque CA28 differed from those described in the previously reported case, demonstrating divergent mutational pathways for change in the coreceptor preference of the R5 SHIV(SF162P3N) isolate in vivo.

Induction of potent local cellular immunity with low dose X4 SHIV(SF33A) vaginal exposure.

Intravaginal inoculation of rhesus macaques with varying doses of the CXCR4 (X4)-tropic SHIV(SF33A) isolate revealed a threshold inoculum for establishment of systemic virus infection and a dose dependency in overall viral burden and CD4+ T cell depletion. While exposure to inoculum size of 1000 or greater 50% tissue infectious dose (TCID(50)) resulted in high viremia and precipitous CD4+ T cell loss, occult infection was observed in seven of eight macaques exposed to 500 TCID(50) of the same virus. The latter was characterized by intermittent detection of low level virus with no evidence of seroconversion or CD4+ T cell decline, but with signs of an ongoing antiviral T cell immune response. Upon vaginal re-challenge with the same limiting dose 11-12 weeks after the first, classic pathogenic X4 SHIV(SF33A) infection was established in four of the seven previously exposed seronegative macaques, implying enhanced susceptibility to systemic infection with prior exposure. Pre-existing peripheral SIV gag-specific CD4+ T cells were more readily demonstrable in macaques that became systemically infected following re-exposure than those that were not. In contrast, early presence of circulating polyfunctional cytokine secreting CD8+ T cells or strong virus-specific proliferative responses in draining lymph nodes and in the gut associated lymphoid tissue (GALT) following the first exposure was associated with protection from systemic re-infection. These studies identify the gut and lymphoid tissues proximal to the genital tract as sites of robust CD8 T lymphocyte responses that contribute to containment of virus spread following vaginal transmission.

Efficient repeated low-dose intravaginal infection with X4 and R5 SHIVs in rhesus macaque: implications for HIV-1 transmission in humans.

We examined the effect of inoculum dose on SHIV transmission and infection. We found that repeated low-dose intravaginal exposure with either R5-SHIV(SF162P3) or X4-SHIV(SF33A) results in infections that are blunted and rapidly controlled. Interestingly, although the transmission rate after all repeated exposures is comparable for the two viruses, the probability of low-dose vaginal transmission is greater for the X4 than R5 virus. Furthermore, X4-SHIV(SF33A) replication predominates in low-dose dually-exposed macaques, suggesting that it is better at establishing a systemic infection following transmission. However, X4-SHIV(SF33A) advantage in transmission and infection is not observed in macaques inoculated intravenously with low-dose mixed inoculum. The finding that although matched in tissue culture infectious dose, the X4 inoculum is more complex leads us to hypothesize that the greater genetic heterogeneity of the X4 virus population may have rendered it less susceptible to the severe bottleneck effects imposed by IVAG inoculation with small doses, allowing for greater probability of transmission and establishment of a generalized infection. These data have implications for HIV-1 transmission and infection in humans.

Progestin-based contraceptive suppresses cellular immune responses in SHIV-infected rhesus macaques.

Nine rhesus macaques in groups of three received a single dose of the injectable progestin-based contraceptive Depo-Provera 5 weeks prior to challenge intravaginally with varying doses of a mixture of the pathogenic CXCR4 (X4)-SHIV(SF33A) and CCR5 (R5)-SHIV(SF162P3) isolates. As controls, seven Depo-naive animals were inoculated once with a high-dose of the mixed inoculum. Irrespective of inoculum dose, acute viremia was higher in the Depo-treated than in the Depo-naive animals. Further, genetic complexity of the replicating virus was greater and replication of the X4 virus was favored in dually infected animals treated with Depo-Provera. Analysis of cellular immune responses revealed slower response rates in virus-specific IFN-gamma production to SIV Gag in the Depo-treated macaques. The immunosuppressive effect of Depo-Provera on mounting an antiviral cellular immune response may account for the increase viral burden and diversity, and the predominance of X4 virus replication in SHIV infected macaques that were administered the progestin-based contraceptive.