Abstract 5652: Translational evidence of reactivated innate and adaptive immunity with intratumoral IMO-2125 in combination with systemic checkpoint inhibitors from a Phase I/II study in patients with anti-PD-1 refractory metastatic melanoma

Background: While checkpoint inhibitor (CPI) therapy has transformed metastatic melanoma (MM) treatment, many patients remain refractory. We reasoned that combining CPI with an agent that activates antigen presenting cells and improves T-cell priming may result in improved response. Our approach is to modulate the tumor microenvironment through image-guided intratumoral (i.t.) injection of the TLR9 agonist, IMO-2125, in combination with either ipilimumab (ipi) or pembrolizumab (pembro). We hypothesize that this will result in dendritic cell (DC) activation and induction of tumor-specific CD8+T-cells which will synergize with ipilimumab or pembrolizumab to overcome immune-escape. Based on this rationale we initiated a phase I/II clinical trial.

Study Design/Methods: Adults with refractory MM that have had prior PD-1 blockade therapy (with or without a BRAF inhibitor) are eligible. IMO-2125, in doses escalating from 4mg to 32mg, is given i.t. weeks 1, 2, 3, 5, 8, and 11 along with standard doses of ipilimumab or pembrolizumab. Primary endpoints are safety, tumor response, and PK. Multiple biopsies are obtained in both the injected and distant tumor pre- and on-treatment. Immune analyses include DC subsets and their activation status as well as T cell activation, function and proliferation. T-cell repertoire diversity is evaluated by high-throughput CDR3 sequencing and changes in gene expression signatures are assessed by nanoString. Changes in circulating cytokines are also being assessed during therapy.

Results: Enrollment is proceeding on both the IMO-ipilimumab and IMO-pembrolizumab dose-escalation arms of the trial. Safety is acceptable with no DLT recorded to date. Durable clinical responses (including 1 CR) have been observed with IMO-ipilimumab in patients who were refractory to PD-1 inhibitor. Fresh tumor biopsies show maturation (upregulation of HLA-DR) of the myeloid DC1 subset (CD1c+CD303-), upregulation of PD-L1 by malignant cells, as well as an IFNα response gene signature in the IMO-2125 injected tumor lesion 24 hrs post-treatment compared to pre-treatment biopsy. On-treatment biopsy results show a higher expression of CD56+ and Ki67+ effector CD8+ T-cells in responding patients. Initial CDR3 sequencing demonstrates increased diversity in the injected lesions of all patients assessed and expansion of top clones present in the distant lesion in a responding patient. Plasma analysis showed an increase in IFNγ levels in the plasma of responding patients.

Conclusions: These results demonstrate that IMO-2125 with a checkpoint inhibitor is a viable strategy to revive the immune response in tumors that are refractory to PD-1 inhibitors. Further clinical evaluation of both the IMO-ipilimumab and IMO-pembrolizumab combination is planned in a Phase 2 expansion of the current trial.

Citation Format: Cara Haymaker, Marc Uemura, Ravi Murthy, Marihella James, Daqing Wang, Julie Brevard, Suzanne Swann, James Geib, Mark Cornfeld, Srinivas Chunduru, Sudhir Agrawal, Cassian Yee, Jennifer Wargo, Rodabe Amaria, Sapna Patel, Hussein Tawbi, Isabella Glitza, Scott Woodman, Wen-Jen Hwu, Michael A. Davies, Patrick Hwu, Willem Overwjik, Chantale Bernatchez, Adi Diab. Translational evidence of reactivated innate and adaptive immunity with intratumoral IMO-2125 in combination with systemic checkpoint inhibitors from a Phase I/II study in patients with anti-PD-1 refractory metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5652. doi:10.1158/1538-7445.AM2017-5652

Intratumoral (i.t.) IMO-2125 (IMO), a TLR9 agonist, in combination with ipilimumab (ipi) in PD-(L)1 refractory melanoma (RM)

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Background: Checkpoint inhibitors (CPI) have transformed melanoma treatment but many patients remain refractory. CPI plus i.t. IMO may improve response by activating innate immune function. Based on this we initiated a trial of IMO in combination with ipi or pembrolizumab (pem) in RM. Methods: Adults with RM that progressed during or after ≥ 12 weeks of PD-1 therapy are eligible. IMO, 4 – 32 mg, is given i.t. for 6 doses, along with either ipi or pem. Endpoints are safety, response, biomarkers, and PK. Injected and distant tumors are biopsied pre-treatment and again at 24 hrs (injected tumor), weeks 8 and 13 for immune analyses. Results: As of October 7, 2016, 10 pts have been treated; median age 55 (range: 39-76), 8 with visceral and 1 with brain metastases. Two pts have mucosal histology. 60% have BRAF mutations. Prior duration of anti-PD-(L)1 therapy ranges from 8 to 63 weeks and median time from last PD-1 therapy to onset of study treatment is 6 (4,57) weeks. IMO has been administered at 4, 8, and 16 mg. No DLTs have been observed and there have been no treatment-related discontinuations or deaths. Ipi was discontinued after the second dose in one subject with previous ipi-related hepatitis for recurrent transaminase elevations (grade 4). Grade 3 hypophysitis is the only other immune-related AE (2 pts). Most frequent TEAE (N > 2) are nausea, vomiting, anemia, diarrhea, increases in ALT/AST/GGT/triglycerides, chills, fatigue, pyrexia, and leukopenia; the majority are low-grade. 6 patients are evaluable for response - CR (1), PR (2), SD (2), PD (1) by RECIST1.1. Tumor biopsies show consistent maturation of the myeloid DC1 subset in IMO injected tumors at 24 hrs. Week 8 results are consistent with a higher rate of proliferative (Ki67) effector CD4+ and CD8+ T-cells in responders. Circulating IFNγ shows 2-3 fold increase in responders. Conclusions: The combination of IMO and ipi is tolerable and has activity in PD-1 refractory melanoma. Dose escalation is ongoing and a Phase 2 expansion with both combinations is planned. Updated safety, antitumor activity, PK, and biomarker data will be presented at the meeting. Clinical trial information: NCT02644967.

Pembrolizumab (pembro) plus low-dose ipilimumab (ipi) for patients (pts) with advanced renal cell carcinoma (RCC): Phase 1 KEYNOTE-029 study

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Background: The CTLA-4 antibody ipi and the PD-1 antibody pembro have demonstrated efficacy in pts with advanced malignancies. While these immune checkpoint inhibitors have shown robust activity as monotherapy, combination therapy may further improve outcomes. KEYNOTE-029 (NCT02089685) is a phase 1/2 study designed to assess the safety and efficacy of pembro + ipi or pegylated interferon alfa-2b (IFN-α) in pts with advanced melanoma or RCC. Here we report data from the phase 1 portion of the study in pts with RCC treated with pembro + ipi. Methods: Pts ≥18 years with advanced/unresectable or metastatic clear cell RCC who received ≥1 prior therapy for metastatic disease, had ≥1 measurable lesion per RECIST v1.1, and ECOG PS 0-1 were enrolled. Pts received pembro 2 mg/kg Q3W + low-dose ipi (1 mg/kg Q3W for 4 doses) until disease progression, unacceptable toxicity, investigator/patient decision, or 2 years of pembro treatment. AEs were monitored throughout treatment and for 30 days thereafter and graded per NCI CTCAE v4.0. Primary end point was safety; primary efficacy end point was ORR assessed per RECIST v1.1 by independent central imaging vendor review. Results: As of the March 17, 2016, data cutoff, 10 pts with RCC received pembro + low-dose ipi. 60% were male, 70% were white, median age was 61 years (range, 48-70 years), 40% received 2 prior lines of therapy, and 40% received prior immunotherapy. With a median follow-up of 17.4 months (0.9-23.5 months), 70% of pts experienced treatment-related AEs (TRAEs) of any grade, most commonly fatigue (30%); and 50% experienced grade 3/4 TRAEs, most commonly increased lipase (20%). 50% of pts discontinued pembro because of TRAEs, most commonly increased lipase (40%). There were no treatment-related deaths. ORR was 20% (2 partial responses); median duration of response was not reached (14.1+-17.1 months+). An additional 3 pts had stable disease; disease control rate was 50%. Conclusions: The combination of pembro + low-dose ipi for 4 doses, followed by pembro monotherapy, demonstrates a manageable toxicity profile and preliminary antitumor activity in pts with advanced RCC. Clinical trial information: NCT02089685.

Effectiveness and cost-effectiveness of a brief school-based group programme for parents of children at risk of ADHD: a cluster randomised controlled trial

BACKGROUND

National Institute for Health and Care Excellence guidelines recommend a stepped care approach for the identification and management of children with, or at risk of, attention-deficit/hyperactivity disorder (ADHD). We investigated the effectiveness, cost-effectiveness and acceptability of a group parenting intervention programme (+/- a teacher session) for children at risk of ADHD.

METHODS

In a three-arm cluster randomised controlled trial, 12 primary schools were randomly assigned to control, parent-only and combined (parent + teacher) intervention arms. Eligible children had high levels of parent-rated hyperactivity/inattention (n = 199). At 6 month follow-up, the primary outcome measure was the parent-completed Conners' Rating Scale - Revised (ADHD index). Secondary outcomes included the Conners' sub-scales (hyperactivity, cognitive problems/inattention and oppositional behaviour), the teacher-completed Conners' Rating Scale - Revised, child health-related quality of life, parental burden and parental mental health. The cost-effectiveness analyses reflected a health and personal social services perspective.

TRIAL REGISTRATION

ISRCTN87634685.

RESULTS

Follow-up data were obtained from 76 parents and 169 teachers. There was no effect of the parent-only (mean difference = -1.1, 95% CI -5.1,2.9; p = 0.57) or combined interventions (mean difference = -2.1, 95% CI -6.4,2.1; p = 0.31) on the ADHD index. The combined intervention was associated with reduced parent-reported hyperactivity symptoms (mean difference = -5.3; 95% CI -10.5,-0.01; p = 0.05) and the parent-only intervention with improved parental mental health (mean difference = -1.9; 95% CI -3.2,-0.5; p = 0.009). The incremental costs of the parent-only and the combined interventions were £73 and £123, respectively. Above a willingness-to-pay of £31 per one-point improvement in the ADHD index, the parent-only programme had the highest probability of cost-effectiveness. Participants found the interventions acceptable.

CONCLUSIONS

For children at risk of ADHD, this school-based parenting programme was not associated with improvement in core ADHD symptoms. Secondary analyses suggested a possible reduction in parent-reported hyperactivity and parental mental health problems. Future research should compare targeted interventions against watchful waiting and specialist referral.

Current Evidence for the Use of Laminar Flow in Reducing Infection Rates in Total Joint Arthroplasty

Since the introduction of laminar air flow in orthopaedic theatres by Sir John Charnley, it has widely become accepted as the standard during orthopaedic procedures such as joint arthroplasty. We present a review of available current literature for the use of laminar flow operating theatre ventilation during total joint arthroplasty and examines the effectiveness of laminar flow ventilated operating theatres in preventing post-operative wound infection. Results of our findings suggest that while bacterial and air particulate is reduced by laminar air flow systems, there is no conclusive effect on the reduction of post-operative wound infections following total joint arthroplasty. We conclude that a combination of strict aseptic technique, prophylactic antibiotics and good anaesthetic control during surgery remains crucial to reduce post-operative surgical infections.