Circulating Cytokines in Metastatic Breast Cancer Patients Select Different Prognostic Groups and Patients Who Might Benefit from Treatment beyond Progression

Cancer induces immune suppression to overcome its recognition and eradication by the immune system. Cytokines are messengers able to modulate immune response or suppression. There is great interest in the evaluation of their changes during treatment in order to identify their relationship with clinical outcome. We evaluated 18 cytokines in breast cancer patients treated with eribulin before starting treatment (T0) and after four courses of therapy (T1). Longitudinal modifications were considered and cytokine clusters through PCA and HCPC correlated to patients’ outcomes were identified. Forty-one metastatic breast cancer patients and fifteen healthy volunteers were included. After clustering, we identified at T0 six patient clusters with different risk of relapse and death. At T1, only four clusters were identified, and three of them accounted for thirty-eight of forty-one patients, suggesting a possible role of treatment in reducing heterogeneity. The cluster with the best survival at T1 was characterized by low levels of IL-4, IL-6, IL-8, IL-10, CCL-2, CCL-4, and TGF-β. The cluster showing the worst survival encompassed high levels of IL-4, IL-6, IL-8, IL-10, CCL-2, and IFN-γ. A subgroup of patients with short progression-free survival (PFS) and long overall survival (OS) was comprised of in the cluster characterized by low levels of CCL-2, IL-6, IL-8, IL-10, and IL-12 at T0. Our data support the prognostic significance of longitudinal serum cytokine analysis. This approach may help identify patients for whom early treatment stop avoids needless toxicity or might justify treatment beyond early progression. Further investigations are required to validate this hypothesis.

Tumor Growth Rate Decline Despite Progressive Disease May Predict Improved Nivolumab Treatment Outcome in mRCC: When RECIST Is Not Enough

Treatment response is usually assessed by the response evaluation criteria in solid tumors (RECIST). These criteria may not be adequate to evaluate the response to immunotherapy, considering the peculiar patterns of response reported with this therapy. With the advent of immunotherapy these criteria have been modified to include the evaluation of the peculiar responses seen with this type of therapy (iRECIST criteria), including pseudoprogressions and hyperprogressions. Tumor growth rate (TGR) is a dynamic evaluation that takes into account the kinetics of response to treatment and may help catch the real efficacy of an immunotherapy approach. We performed a retrospective monocentric study to explore the impact of TGR change after nivolumab administration as the second or later line of treatment in patients with metastatic renal cell carcinoma (RCC). We evaluated 27 patients, divided into three categories: Disease control (DC) if there was no PD; lower velocity PD (LvPD) if disease progressed but the TGR at second assessment (TGR2) was lower than the TGR at first assessment (TGR1); higher velocity PD (HvPD) if TGR2 was higher than TGR1. The median OS for the DC group was 11.0 months (95% CI 5.0–17.0) (reference) vs. (not reached) NR (95% CI NR-NR) for LvPD (HR 0.27; 95% CI 0.06–1.30; p 0.102) vs. NR (95% CI NR–NR) for HvPD (HR 0.23; 95% CI 0.06–0.88; p 0.032). There was no difference between LvPD and DC (HR 1.21; 95% CI 0.20–7.28; p 0.838). In patients with metastatic RCC, the second or later line of nivolumab treatment may lead to a deceleration in TGR resulting in an improved survival outcome similar to that observed in patients experiencing tumor regression. In this subgroup, especially in the presence of a clinical benefit, continuing the treatment beyond progression can be recommended.

Treatment beyond progression with immune checkpoint inhibitors in advanced melanoma.

e21541 Background: Immunotherapy (ITH) holds the possibility of tumor burden decrease after initial RECIST defined progression (PD). Clinical concept of treating of selected patients (pts) beyond PD is supported by this pseudoprogression phenomenon. The aim of this study was to evaluate real-life practice and outcomes related to treatment beyond progression (TBP) in melanoma patients. Methods: We evaluated advanced melanoma pts who started anti-PD1 treatment between 12/2015 and 12/2018 and identified pts who received TBP and had subsequent imaging to evaluate the tumor burden. Survival analyses were performed using the Kaplan-Meier method, Log-rank, chi-square and Fisher exact tests were used for comparison between groups. Data cut-off was 02/2021. Results: Of 399 subsequent melanoma pts treated, 57 (14%) patients received TBP. Anti-PD1 was 1st line treatment in 61.4% and 2nd line - in 38.6% of patients. 71.9% patients were diagnosed with skin, 7.0% - mucosal and 21.1% with FPI melanoma and 47.4% were BRAF mutated, 56.1% were male and 12.3% had 3 or more metastatic sites at treatment initiation. In this cohort median time to 1st PD (TTFP) was 4.43 months(m), while to 2nd PD (TTSP) – 8.01 m. On TBP 26.3% pts achieved objective response (OR), and next 42.1% - SD. 1st PD was reported most often as increase in 3 or more targets or one new lesion – both 22.8%; and in 24.6% cases involved central nervous system. In 56.8% second PD was observed in the same targets as 1st PD. 61.4% patients received multimodal treatment of ITH combined with radiation therapy – in 49.1%, surgery - 5.3% and both - 7.0%. There was no correlation of TTSP with gender, ECOG, initial disease stage or TNM, BRAF mutation, number of metastatic sites or pattern of progression. Multimodal treatment resulted in 13.6 m TTSP, while ITH alone - 8.0 m (p = 0.056). 1st line OR correlated with DCR on TBP while TTFP > 6 m correlated with TTSP (HR = 0.53, 95%CI 0.28-0.99). Patients with 1st line CR – had median TTSP 16.4 m, with PR – 23.5 m, while those with PD – 5.1 m. Median OS after 1st PD was 26 months and correlated with OR on TBP. Conclusions: Selected clinically fit melanoma patients despite evidence of first radiographic progression may benefit from continued treatment with PD-1 inhibitors. Multidisciplinary treatment should be offered to these patients including radiosurgery or stereotactic radiotherapy of progressing loci. Molecular biomarkers of TTSP should be analyzed in prospective studies.

Treatment beyond progression with anti-PD-1/PD-L1 based regimens in advanced solid tumors: a systematic review

Background Treatment beyond progression with immunotherapy may be appropriate in selected patients based on the potential for late responses. The aim of this systematic review was to explore the impact of treatment beyond progression in patients receiving an anti-PD-1/PD-L1 based regimen for an advanced solid tumor. Methods A systematic literature search was performed to identify prospective clinical trials reporting data on overall response rate by immune-related criteria and/or the number of patients treated beyond conventional criteria-defined PD and/or the number of patients achieving a clinical benefit after an initial PD with regimens including an anti-PD-1/PD-L1 agent which received the FDA approval for the treatment of an advanced solid tumor. Results 254 (4.6%) responses after an initial RECIST-defined progressive disease were observed among 5588 patients, based on 35 trials included in our analysis reporting this information. The overall rate of patients receiving treatment beyond progressive disease was 30.2%, based on data on 5334 patients enrolled in 36 trials, and the rate of patients who achieved an unconventional response among those treated beyond progressive disease was 19.7% (based on 25 trials for a total of 853 patients). Conclusion The results of our systematic review support the clinical relevance of unconventional responses to anti-PD-1/PD-L1-based regimens; however, most publications provided only partial information regarding immune-related clinical activity, or did not provide any information at all, highlighting the need of a more comprehensive report of such data in trials investigating immunotherapy for the treatment of patients with advanced tumors.

Nivolumab in previously treated advanced gastric cancer (ATTRACTION-2): 3-year update and outcome of treatment beyond progression with nivolumab

Background ATTRACTION-2 demonstrated that nivolumab improved overall survival (OS) vs placebo in patients with advanced gastric cancer treated with ≥ 2 chemotherapy regimens. However, its long-term efficacy and outcome of treatment beyond progression (TBP) with nivolumab have not been clarified. Methods The 3-year follow-up data were collected. A subset analysis was performed to explore the efficacy of TBP by assessing postprogression survival (PPS) after the first event of disease progression. Results Overall, 493 patients were randomized (2:1) to receive nivolumab (n = 330) or placebo (n = 163). With a median follow-up of 38.5 (range 36.1–47.5) months, OS of the nivolumab group was significantly longer compared to the placebo group (median 5.3 vs 4.1 months; 3-year survival rate, 5.6% vs 1.9%; hazard ratio [HR], 0.62 [95% confidence interval (CI) 0.50–0.75], P < 0.0001). The median OS of responders (n = 32) who achieved complete response or partial response was 26.7 months and the 3-year survival rate was 35.5% in the nivolumab group. Overall, 109 patients in the nivolumab group and 37 patients in the placebo group received TBP. PPS tended to be longer in the nivolumab group vs placebo group (median 5.8 vs 4.5 months; HR [95% CI], 0.69 [0.47–1.01], P = 0.057). In contrast, PPS was similar between both treatment groups in non-TBP patients (median 2.3 vs 2.2 months; HR 0.90, P = 0.42). Conclusions Long-term efficacy of nivolumab was confirmed at the 3-year follow-up, and a survival benefit of TBP with nivolumab was suggested. Biomarkers for selecting patients suitable for TBP with nivolumab should be identified in the future.

666 Analyzing regulatory requirements in the development of immune checkpoint inhibitors using Artificial Intelligence

BackgroundSince the approval of the first immune checkpoint inhibitor (ICI) targeting CTLA-4 in 2011 (ipilimumab), six others, targeting the PD-1/PD-L1, have been approved by FDA for a total of more than 19 indications,6,7,8 and the number is growing. These approvals paved the way for rapid growth in the number of candidates in the pipelines. It is critical for these candidates to pursue the right development strategy to demonstrate their potential to regulatory authorities and reach patients without delay. Unexpected challenges in such a competitive field risks leading to expensive modifications and possible discontinuations. This is compounded by the lack of clarity in important development questions such as study design,5 the choice of endpoints and appropriate statistical methods.1,2,3 In this regard, FDA’s guidance document4 provides a useful summary of the topics encountered by clinical development practitioners such as endpoints, clinical trial design and statistical analysis. However, it does not capture the unique challenges of the checkpoint inhibitor space, namely traditional phase I study designs and their ability to predict dosing and detect dose-related toxicities1 and endpoint selection given the unconventional response patterns.2MethodsThe approval packages of the seven FDA-approved ICIs contain a wealth of information related to the focus areas, expectations and concerns of the agency. However, they run into thousands of pages, which renders manual analysis too time-consuming and/or incomplete. In this work, we use Regulatory Foresight, a proprietary AI software tool developed by Biotech Square Inc., that employs state-of-the-art techniques in Computer Vision, Natural Language Processing and Machine Learning to extract, standardize, and analyze interactions from drug and biologic applications reviewed by FDA.ResultsUsing Regulatory Foresight, we discovered (a) the major topics of interest and concerns of the FDA, (b) the commonalities and differences in topics between the individual ICIs, (c) the evolution of topics from the oldest to the most recently approved ICI, and (d) the unaddressed topics in official FDA guidance documents.ConclusionsThis work successfully uncovers regulatory requirements in the development of immune checkpoint inhibitors using AI algorithms in order for sponsors to (a) optimize strategies for development of new drugs, (b) better understand regulatory expectations, and (c) adequately prepare for meetings and submissions to regulatory agencies. In addition this work discovers the current gaps in official FDA guidance documents so that they may be adequately addressed in future versions.ReferencesJardim DL, de Melo Gagliato D, Kurzrock R. Lessons From the Development of the Immune Checkpoint Inhibitors in Oncology. Integr Cancer Ther 2018;17(4):1012–1015. doi:10.1177/1534735418801524Ferrara R, Pilotto S, Caccese M, et al. Do immune checkpoint inhibitors need new studies methodology?. J Thorac Dis2018;10(Suppl 13):S1564–S1580. doi:10.21037/jtd.2018.01.131‘Impact Story: Determining the Clinical Benefit of Treatment Beyond Progression with Immune Checkpoint Inhibitors’ US FDA Regulatory Science Impact Story. Accessed on the 26th of July 2020: https://www.fda.gov/drugs/regulatory-science-action/impact-story-determining-clinical-benefit-treatment-beyond-progression-immune-checkpoint-inhibitors‘Clinical trial endpoints for the approval of cancer drugs and biologics’ Guidance for industry. US Department of Health and Human Services, FDA, Oncology Center of Excellence, CDER, CBER. December 2018Gong, J., Chehrazi-Raffle, A., Reddi, S. et al. Development of PD-1 and PD-L1 inhibitors as a form of cancer immunotherapy: a comprehensive review of registration trials and future considerations. J. Immunotherapy cancer 2018;6:8. https://doi.org/10.1186/s40425-018-0316-zVaddepally RK, Kharel P, Pandey R, Garje R, Chandra AB. Review of Indications of FDA-Approved immune checkpoint inhibitors per NCCN guidelines with the level of evidence. Cancers (Basel) 2020;12(3):738. Published 2020 Mar 20. doi:10.3390/cancers12030738PD1/PD-L1Landscape. Cancer Research Institute. Accessed on the 26th of July 2020. https://www.cancerresearch.org/scientists/immuno-oncology-landscape/pd-1-pd-l1-landscapeImmuno-Oncology Landscape. Cancer Research Institute. Accessed on the 26th of July 2020. https://www.cancerresearch.org/scientists/immuno-oncology-landscape

CTNI-67. EFFICACY AND SAFETY OF LAROTRECTINIB IN PATIENTS WITH TROPOMYOSIN RECEPTOR KINASE (TRK) FUSION PRIMARY CENTRAL NERVOUS SYSTEM (CNS) TUMORS: AN EXPANDED DATASET

BACKGROUND TRK fusion proteins are oncogenic drivers of various CNS and non-CNS tumors. Larotrectinib, a highly selective FDA- and EMA-approved TRK inhibitor, demonstrated an objective response rate (ORR) of 79% across various non-CNS cancers (Hong et al. Lancet Oncol. 2020). We report data in an expanded set of TRK fusion primary CNS tumors treated with larotrectinib. METHODS Patients with primary CNS tumors harboring an NTRK gene fusion treated with larotrectinib in two clinical trials (NCT02637687, NCT02576431) were identified. Disease status was investigator-assessed (RANO). Data cutoff: July 15, 2019. RESULTS Twenty-four patients with TRK fusion primary CNS tumors were identified. Eighteen patients had gliomas (13 high-grade and five low-grade). Median age was 8.0 years (range 1.3–79.0), with 20 patients &lt; 18 years old. ORR was 29% (95% CI 13–51%); best responses were two complete responses, five partial responses (two pending confirmation), 15 stable disease, and two progressive disease. The 24-week disease control rate was 63% (95% CI 41–81%). For the five confirmed responders, median time to best response was 1.8 months and median duration of response was 4.9 months (range 1.7+ to 10.1+). Median progression-free survival was 11.0 months (range 1.1 to 19.8+) and median overall survival was not reached (range 1.9+ to 21.4+) at a median follow-up of 6.0 months. Treatment duration ranged from 1.2 to 21.4+ months; three patients continued treatment beyond progression. Treatment-emergent adverse events (TEAEs) were mainly Grade 1 and 2. Grade 3–4 TEAEs occurred in 10 patients, with two deemed related to larotrectinib. The most common neurological TEAE was headache in three patients (Grade 1–2). No patients discontinued larotrectinib due to AEs. CONCLUSIONS Larotrectinib was active and well tolerated in patients with TRK fusion primary CNS tumors. These results support testing for NTRK gene fusions in patients with primary CNS tumors.