Phase I/II trial of subcutaneous interleukin-2, granulocyte-macrophage colony-stimulating factor and interferon-α in patients with metastatic renal cell carcinoma

Is more better? An analysis of toxicity and response outcomes from dose-finding clinical trials in cancer

BACKGROUND

The overwhelming majority of dose-escalation clinical trials use methods that seek a maximum tolerable dose, including rule-based methods like the 3+3, and model-based methods like CRM and EWOC. These methods assume that the incidences of efficacy and toxicity always increase as dose is increased. This assumption is widely accepted with cytotoxic therapies. In recent decades, however, the search for novel cancer treatments has broadened, increasingly focusing on inhibitors and antibodies. The rationale that higher doses are always associated with superior efficacy is less clear for these types of therapies.

METHODS

We extracted dose-level efficacy and toxicity outcomes from 115 manuscripts reporting dose-finding clinical trials in cancer between 2008 and 2014. We analysed the outcomes from each manuscript using flexible non-linear regression models to investigate the evidence supporting the monotonic efficacy and toxicity assumptions.

RESULTS

We found that the monotonic toxicity assumption was well-supported across most treatment classes and disease areas. In contrast, we found very little evidence supporting the monotonic efficacy assumption.

CONCLUSIONS

Our conclusion is that dose-escalation trials routinely use methods whose assumptions are violated by the outcomes observed. As a consequence, dose-finding trials risk recommending unjustifiably high doses that may be harmful to patients. We recommend that trialists consider experimental designs that allow toxicity and efficacy outcomes to jointly determine the doses given to patients and recommended for further study.

Would the Recommended Dose Have Been Different Using Novel Dose-Finding Designs? Comparing Dose-Finding Designs in Published Trials

Simulation studies have shown that novel designs such as the continual reassessment method and the Bayesian optimal interval (BOIN) design outperform the 3 + 3 design by recommending the maximum tolerated dose (MTD) more often, using less patients, and allotting more patients to the MTD. However, it is not clear whether these novel designs would have yielded different results in the context of real-world dose-finding trials. This is a commonly mentioned reason for the continuous use of 3 + 3 designs for oncology trials, with investigators considering simulation studies not sufficiently convincing to warrant the additional design complexity of novel designs.

METHODS

We randomly sampled 60 published dose-finding trials to obtain 22 that used the 3 + 3 design, identified an MTD, published toxicity data, and had more than two dose levels. We compared the published MTD with the estimated MTD using the continual reassessment method and BOIN using target toxicity rates of 25% and 30% and toxicity data from the trial. Moreover, we compared patient allocation and sample size assuming that these novel designs had been implemented.

RESULTS

Model-based designs chose dose levels higher than the published MTD in about 40% of the trials, with estimated and observed toxicity rates closer to the target toxicity rates of 25% and 30%. They also assigned less patients to suboptimal doses and permitted faster dose escalation.

CONCLUSION

This study using published dose-finding trials shows that novel designs would recommend different MTDs and confirms the advantages of these designs compared with the 3 + 3 design, which were demonstrated by simulation studies.

Granulocyte macrophage colony-stimulating factor predicts postoperative recurrence of clear-cell renal cell carcinoma

Background

Granulocyte macrophage colony-stimulating factor (GM-CSF) is currently widely used as an adjuvant in cancer immunotherapy. However, recent studies have shown that GM-CSF can impair anti-tumor immune responses. Thus the role of GM-CSF in clear-cell renal cell carcinoma (ccRCC) remains unraveled. Our present study aims to investigate the prognostic significance of intratumoral GM-CSF in patients with clinically localized ccRCC.

Results

A high intratumoral GM-CSF expression was significantly associated with lymph node metastases (P = 0.009), high TNM stage (P = 0.031), high Fuhrman grade (P < 0.001), presence of tumor necrosis (P = 0.005), and high Leibovich scores (P < 0.001). In addition, the prognostic significance of intratumoral GM-CSF expression was restricted to patients with Leibovich intermediate/high-risk (P = 0.001). Furthermore, a high intratumoral GM-CSF expression was demonstrated as an independent prognostic factor of reduced RFS (P = 0.018). Incorporation of the intratumoral GM-CSF expression into a prognostic model including TNM stage, Fuhrman grade, tumor necrosis and lymphovascular invasion generated a nomogram, which predicted accurately 3- and 5-year survival for ccRCC patients.

Materials and Methods

This study comprised 233 clinically localized (T1-3N0-1M0) ccRCC patients undergoing nephrectomy in 2008 at a single centre. Intratumoral GM-CSF expression was assessed by immunohistochemical staining and its associations with clinicopathologic features and recurrence-free survival (RFS) were evaluated.

Conclusions

The intratumoral GM-CSF expression, as a potentially independent prognostic biomarker for recurrence, might improve conventional clinical and pathologic analysis to refine outcome prediction for clinically localized ccRCC patients after surgery.

A chemically defined trifunctional antibody-cytokine-drug conjugate with potent antitumor activity

The combination of immunostimulatory agents with cytotoxic drugs is emerging as a promising approach for potentially curative tumor therapy, but advances in this field are hindered by the requirement of testing individual combination partners as single agents in dedicated clinical studies, often with suboptimal efficacy. Here, we describe for the first time a novel multipayload class of targeted drugs, the immunocytokine-drug conjugates (IDC), which combine a tumor-homing antibody, a cytotoxic drug, and a proinflammatory cytokine in the same molecular entity. In particular, the IL2 cytokine and the disulfide-linked maytansinoid DM1 microtubular inhibitor could be coupled to the F8 antibody, directed against the alternatively spliced EDA domain of fibronectin, in a site-specific manner, yielding a chemically defined product with selective tumor-homing performance and potent anticancer activity in vivo, as tested in two different immunocompetent mouse models.

Influence of human immune cells on cancer: studies at the University of Colorado

There will be over half a million cancer-related deaths in the United States in 2012, with lung cancer being the leader followed by prostate in men and breast in women. There is estimated to be more than one and a half million new cases of cancer in 2012, making the development of effective therapies a high priority. As tumor immunologists, we are interested in the development of immunotherapies because the immune response offers exquisite specificity and the potential to target tumor cells without harming normal cells. In this review, we highlight the current advances in the field of immunotherapy and the current work being completed by laboratories at University of Colorado School of Medicine in multiple malignancies, including breast cancer, lung cancer, melanoma, thyroid cancer, and glioblastoma. This work focuses on augmenting the anti-tumor response of CD8 T cells in the blood, lymph nodes, and tumors of patients, determining biomarkers for patients who are more likely to respond to immunotherapy, and identifying additional anti-tumor and immunosuppressive cells that influence the overall response to tumors. These collaborative efforts will identify mechanisms to improve immune function, which may elucidate therapeutic targets for clinical trials to improve patient health and survival.

Trial Watch: Immunostimulatory cytokines

During the past two decades, the notion that cancer would merely constitute a cell-intrinsic disease has gradually been complemented by a model postulating that the immune system plays a relevant role during all stages of oncogenesis and tumor progression. Along with this conceptual shift, several strategies have been devised to stimulate tumor-specific immune responses, including relatively unselective approaches such as the systemic administration of adjuvants or immunomodulatory cytokines. One year ago, in the July issue of OncoImmunology, we described the main biological features of this large group of proteins and discussed the progress of ongoing clinical studies evaluating their safety and therapeutic potential in cancer patients. Here, we summarize the latest developments in this area of clinical research, focusing on high impact studies that have been published during the last 13 mo and clinical trials launched in the same period to investigate which cytokines can be employed as safe and efficient immunostimulatory interventions against cancer.

Immunotherapy of genitourinary malignancies

Most cancer patients are treated with some combination of surgery, radiation, and chemotherapy. Despite recent advances in local therapy with curative intent, chemotherapeutic treatments for metastatic disease often remain unsatisfying due to severe side effects and incomplete long-term remission. Therefore, the evaluation of novel therapeutic options is of great interest. Conventional, along with newer treatment strategies target the immune system that suppresses genitourinary (GU) malignancies. Metastatic renal cell carcinoma and non-muscle-invasive bladder caner represent the most immune-responsive types of all human cancer. This review examines the rationale and emerging evidence supporting the anticancer activity of immunotherapy, against GU malignancies.