Pembrolizumab plus azacitidine in patients with chemotherapy refractory metastatic colorectal cancer: a single-arm phase 2 trial and correlative biomarker analysis

Background DNA mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC) is not responsive to pembrolizumab monotherapy. DNA methyltransferase inhibitors can promote antitumor immune responses. This clinical trial investigated whether concurrent treatment with azacitidine enhances the antitumor activity of pembrolizumab in mCRC. Methods We conducted a phase 2 single-arm trial evaluating activity and tolerability of pembrolizumab plus azacitidine in patients with chemotherapy-refractory mCRC (NCT02260440). Patients received pembrolizumab 200 mg IV on day 1 and azacitidine 100 mg SQ on days 1–5, every 3 weeks. A low fixed dose of azacitidine was chosen in order to reduce the possibility of a direct cytotoxic effect of the drug, since the main focus of this study was to investigate its potential immunomodulatory effect. The primary endpoint of this study was overall response rate (ORR) using RECIST v1.1., and secondary endpoints were progression-free survival (PFS) and overall survival (OS). Tumor tissue was collected pre- and on-treatment for correlative studies. Results Thirty chemotherapy-refractory patients received a median of three cycles of therapy. One patient achieved partial response (PR), and one patient had stable disease (SD) as best confirmed response. The ORR was 3%, median PFS was 1.9 months, and median OS was 6.3 months. The combination regimen was well-tolerated, and 96% of treatment-related adverse events (TRAEs) were grade 1/2. This trial was terminated prior to the accrual target of 40 patients due to lack of clinical efficacy. DNA methylation on-treatment as compared to pre-treatment decreased genome wide in 10 of 15 patients with paired biopsies and was significantly lower in gene promoter regions after treatment. These promoter demethylated genes represented a higher proportion of upregulated genes, including several immune gene sets, endogenous retroviral elements, and cancer-testis antigens. CD8+ TIL density trended higher on-treatment compared to pre-treatment. Higher CD8+ TIL density at baseline was associated with greater likelihood of benefit from treatment. On-treatment tumor demethylation correlated with the increases in tumor CD8+ TIL density. Conclusions The combination of pembrolizumab and azacitidine is safe and tolerable with modest clinical activity in the treatment for chemotherapy-refractory mCRC. Correlative studies suggest that tumor DNA demethylation and immunomodulation occurs. An association between tumor DNA demethylation and tumor-immune modulation suggests immune modulation and may result from treatment with azacitidine. Trial registration ClinicalTrials.gov, NCT02260440. Registered 9 October 2014, https://clinicaltrials.gov/ct2/show/NCT02260440.

Touched by Loneliness – How Loneliness Impacts the Response to Observed Human Touch: a tDCS Study

Lonely people often crave connectedness. However, they may also experience their environment as threatening, entering a self-preserving state that perpetuates loneliness. Research shows conflicting evidence about their response to positive social cues, and little is known about their experience of observed human touch. The right inferior frontal gyrus (rIFG) is part of an observation-execution network implicated in observed touch perception. Correlative studies also point to rIFG’s involvement in loneliness. We examined the causal effect of rIFG anodal transcranial direct current stimulation (tDCS) on high and low loneliness individuals observing human touch. In a cross-over design study, 40 participants watched pictures of humans or objects touching or not touching during anodal and sham stimulations. Participants indicated whether pictures contained humans or objects and their reaction time was measured. Results show that the reaction time of low loneliness individuals to observed human touch was significantly slower during anodal stimulation compared to high loneliness individuals, possibly due to them being more emotionally distracted by it. Lonely individuals also reported less liking of touch. Our findings support the notion that lonely individuals are not drawn to positive social cues. This may help explain the perpetuation of loneliness, despite social opportunities that could be available to lonely people.

Characterizing the stress and electrical properties of superconducting molybdenum films

In the process of minimizing stress in sputtered Molybdenum (Mo) films for fabricating transition-edge sensor (TES) devices, we have investigated correlations between the stress and film deposition parameters. At a fixed sputtering power, the tensile stress of our film samples decreases toward both low and high ends of Ar pressure, suggestive of two physical mechanisms at work: an “atomic peening” effect at low Ar pressure and the development of voids at high Ar pressure. We have also carried out correlative studies of the stress and electrical properties (including superconducting critical temperature and residual resistivity) of the film samples, and found that the results are complex. We have made extensive comparisons with the published results, and attempted to explain the discrepancies in terms of film deposition techniques, sample preparation and treatment, and dynamical ranges of measurements. It is fairly clear that the microscopic properties, including porosity and disorder, of Mo films may have significant impact on the correlations.

Use of Belimumab for Prophylaxis of Chronic Graft-Versus-Host Disease

The most transformative approach for controlling chronic Graft-versus-Host Disease (cGvHD) after allogeniec hematopoietic cell transplantation (alloHCT) would be the prevention of its most severe and irreversible clinical manifestations instead of treating already established disease. Belimumab is a monoclonal antibody, approved for treatment of systemic lupus erythematosus and active lupus nephritis, which inhibits binding of B-cell-activating factor (BAFF) to its receptors on B cells, thus inhibiting the survival of autoreactive B cells. Given the role of B cells in cGvHD pathophysiology and the now substantiated role of BAFF in promoting B Cell Receptor signaling in cGvHD (Jia W et al Blood 2021), belimumab might have a role in prevention of cGvHD. We hypothesized that targeting BAFF early after alloHCT would be well-tolerated and have a favorable effect on the incidence and severity of cGvHD. We are presenting data on the first 8/10 patients (Pts) enrolled in the single-center, investigator-initiated phase-1 trial. Belimumab was administered i.v. at 10 mg/kg every 2 weeks for 3 doses followed by 4 doses at monthly intervals, for a total of 7 doses, starting 50-80 days after alloHCT. All Pts were adults who received mobilized peripheral blood grafts from fully matched related or unrelated donors after myeloablative or non-myeloablative conditioning. GvHD prophylaxis was with tacrolimus and methotrexate; one Pt received post-transplant cyclophosphamide. All Pts were in complete remission on day +30 after alloHCT. Pts who received ≥1 dose of belimumab were evaluable for safety and ≥2 doses for efficacy assessment. cGvHD was diagnosed according to the NIH criteria. All analyses are descriptive. Specimens for correlative studies are cryopreserved until the study end. We found that Pts tolerated belimumab well, with no reported grade ≥3 treatment-related adverse events. There were no significant infections or myelosuppression. Seven out of eight Pts on the study received all 7 doses of belimumab, as planned. Of those 7 Pts, 5 Pts are without any evidence of cGvHD and completely off immunosuppression at the median of 18 months (mo) after completing belimumab (median of 24 mo after alloHCT). Seven mo after completing belimumab on study, 1 Pt developed cGvHD involving skin, eyes and liver, and died from complications of pneumonia and liver failure due to longstanding hemochromatosis, iron overload and possible liver GvHD. Another Pt relapsed with leukemia 1 mo after completing belimumab. He is now in remission after treatment with enasidenib and 2 donor lymphocyte infusions (DLI), 12 mo after completing belimumab (18 mo after alloHCT); he developed mild eye GvHD following DLI. One out of eight Pts on the study stopped treatment early, after receiving only 3 doses, due to thrombocytopenia (unrelated to belimumab) and insurance issues. He was found to have relapsed lymphoma 3 mo later, was treated with venetoclax and DLI, and remains in remission with no evidence of cGvHD 15 mo after stopping belimumab. Two additional patients are being enrolled. Immune reconstitution studies are showing that B-cell counts remain low 1 year out of transplant in all Pts (Figure 1). This preliminary data describes for the first time the use of belimumab for prophylaxis of cGvHD. Overall, belimumab was very well tolerated. Only 1 Pt on the study developed cGvHD. It is worth noting that his cGvHD developed 7 mo after completing belimumab suggesting that a longer duration of therapy should be tested in future studies. The 2 Pts with relapsed disease both had high risk malignancies. Risk stratification of high risk patients will be critical in future prospective studies. While more Pts are needed to further assess the impact of prophylactic belimumab on the incidence of cGVHD, these preliminary results are encouraging. Absence of severe infections is reassuring. B-cell reconstitution was delayed, as expected. Ongoing correlative studies will further evaluate BAFF levels and B-cell subset reconstitution after alloHCT. Figure 1 Figure 1. Disclosures Pusic: Syndax: Other: Advisory Board. Sarantopoulos: Rigel: Other: Advisory Board. Uy: Macrogenics: Research Funding; Jazz: Consultancy; Genentech: Consultancy; Astellas: Honoraria, Speakers Bureau; Novartis: Consultancy; AbbVie: Consultancy; GlaxoSmithKline: Consultancy; Agios: Consultancy. OffLabel Disclosure: Drug: Belimumab This study: Belimumab for prophylaxis of chronic GvHD. Approved indication: Belimumab is approved for treatment of systemic lupus erythematosus and active lupus nephritis.

Differences in Gall Induction of Flower-like Galls on Haloxylon by Psyllids (Hemiptera: Aphalaridae), and the Emergence of Corresponding Parasitoids

Saxaul is a kind of dominant perennial psammophyte that widely distributes in arid and semi-arid desert areas, and it has multiple functions in preventing desertification, especially in windbreak and sand fixation. Various gall inducers induce galls on the saxaul, including the flower-like gall. Parasitoids have great potentiality in controlling gall inducers. However, studies about gall inducers and parasitoids of flower-like galls on Haloxylon, as well as the parasitic efficacy of the parasitoids, are rarely reported. In this study, the flower-like galls were observed on Haloxylon ammodendron and H. persicum in Fukang, Xinjiang, China. Two types of flower-like galls were found on H. ammodendron, while only one type was found on H. persicum. In total, five species of gall inducers and three species of parasitoids were obtained from the galls mentioned above. All the galls were induced by Caillardia (Hemiptera: Aphalaridae), which were mostly bivoltine in Fukang. Besides, their parasitoids Psyllaephagus caillardiae and P. longiventris could be observed on all the types of galls. Additionally, correlative studies on the parasitization indexes demonstrated that all the dominant parasitoids of diverse flower-like galls were P. caillardiae, which were slightly more in number than the P. ogazae discovered in the flower bud-like galls. In addition, the relevance between the emergence or lifespan of parasitoids and temperature was also investigated. The results showed that the number of parasitoids emerging decreased rapidly after a period of enhancement with the increase of temperature, including an optimum temperature, while the lifespan of wasps gradually shortened with the temperature rising. Our results highlight the importance of the biological investigation of parasitoids in the gall inducers lived in closed galls, which may provide critical evidence for us to understand its potential application in biological control.

Phase II study of nivolumab and salvage nivolumab + ipilimumab in treatment-naïve patients (pts) with advanced non-clear cell renal cell carcinoma (nccRCC) (HCRN GU16-260-Cohort B).

4510 Background: The HCRN GU16-260 trial reported on the efficacy and toxicity of nivo monotherapy in treatment naïve clear cell RCC (Cohort A) and the efficacy of nivo/ipi salvage therapy in pts with tumors resistant to initial nivo monotherapy (Atkins JCO 2020.38.15_suppl.5006). Limited information is available on the effects of such an approach in pts with advanced nccRCC. Methods: Eligible pts with treatment-naïve nccRCC received nivo 240mg IV q2 wk x 6 doses followed by 360mg IV q3 wk x 4 doses followed by 480 mg q4 wk until progressive disease (PD), toxicity, or completion of 96 wks of treatment (Part A). Pts with PD prior to or stable disease (SD) at 48 wks (pSD) were potentially eligible to receive salvage nivo (3mg/kg) /ipi (1 mg/kg) q3 wk x 4 doses followed by q4 wk nivo maintenance for up to 48 wks (Part B). All pts were required to submit tissue from a metastatic lesion obtained within 12 months (mo) prior to study entry and prior to enrolling on Part B for correlative studies. Results: 35 pts with nccRCC were enrolled between 5/2017 and 12/2019 at 12 participating HCRN sites. Median age 63 (range 35-84 years); 89% male. IMDC favorable 8 (23%), intermediate 18 (51%) and poor risk 9 (26%). Of the 35 pts 19 (54%) had papillary, 6 (17%) chromophobe and 10 (29%) unclassified histology. RECIST defined ORR was 5 of 35 (14.3%) [CR 2 (5.7%), PR 3 (8.6%)], SD 16 (45.7%), PD 14 (40.0%). Immune-related ORR was 8 of 35 (22.9%). RECIST ORR by histology was: papillary - 1/19 (5%); chromophobe - 1/6 (17%); unclassified - 3/10 (30%). 9 pts (26%) had tumors with sarcomatoid features with 3 (33%) (2 unclassified, 1 papillary) responding. Median PFS was 4.0 (2.7, 4.3) mo. 21 pts remain alive. None of the responders have progressed or died. 28 pts (25 PD, 3 pSD) were potentially eligible for salvage nivo/ipi (Part B), but 12 did not enroll due to symptomatic PD (2), grade 3-4 toxicity on nivo (3), or other including no biopsy tissue (7). In the 16 Part B pts, best response to nivo/ipi was: PR (1, 6%) – (unclassified/non-sarcomatoid); SD (7, 44%); PD (8, 50%). Grade 3 Treatment-related adverse events (TrAEs) were seen in 7/35 (20%) on nivo. Grade 3-5 TrAEs were seen in 7/16 (44%) on nivo/ipi with 1 pt experiencing sudden death. Correlative studies including PD-L1 status, WES and RNAseq are pending. Conclusions: Nivo monotherapy has limited activity in treatment naïve nccRCC with most responses (4 of 5) seen in pts with sarcomatoid and/or unclassified tumors. Toxicity is consistent with prior nivo studies. Salvage treatment with nivo/ipi was provided in 16 of 28 (57%) pts with PD/pSD on nivo monotherapy, with 1 response observed. Clinical trial information: NCT03117309.

Multi-center, single arm phase II study of the dual mTORC1/mTORC2 inhibitor vistusertib for patients with recurrent or progressive grade II-III meningiomas.

2024 Background: Grade II/III meningiomas represent about 20% of tumors and have increased rates of recurrence with no approved medical therapies. Historically, the progression-free survival at 6 months (PFS-6) for these tumors is 25%. The Response Assessment in Neuro-Oncology (RANO) group identified a PFS-6 rate of > 35% to be of interest for trials of grade II/III meningioma. Methods : NF2 gene inactivation occurs in the majority of meningiomas and is associated with mTORC1 activation. Human studies of everolimus for neurofibromatosis 2 patients documented growth arrest in only a minority of tumors. Based on our studies showing mTORC2/SGK1 pathway activation in NF2-deficient meningiomas and the known paradoxical activation of the mTORC2/AKT pathway in meningiomas, we hypothesized that dual inhibition of mTORC1/2 would be superior in meningiomas. Treatment of primary meningioma cells with vistusertib led to decreased cell proliferation and showed greater efficacy than rapamycin, regardless of NF2 expression. We studied the effect of vistusertib in patients with progressive or recurrent grade II/III meningiomas (NCT03071874). Vistusertib was administered orally at 125mg twice daily on two consecutive days each week. MRIs were obtained every 2 cycles (1 cycle = 28 days). Tumor size was defined as the largest cross-sectional area. Progression was defined as ≥25% increase in the sum of products of all measurable lesions over smallest sum observed. The primary endpoint was PFS-6. Secondary endpoints included toxicity, radiographic response, and correlative studies including immunohistochemistry for mTORC1/2 pathway activation and genetic biomarkers. Results: Twenty-eight patients (13 female), with a median age of 58 years (range, 32 to 77 years), were enrolled in this multicenter study. The median Karnofsky performance status was 80. Twenty-five patients have been followed to six months or to tumor progression. The median duration of treatment was 6.5 month (range, 1-18 months). Four patients chose to discontinue treatment, 1 withdrew to intercurrent illness, and 1 was withdrawn due to non-compliance. PFS-6 is 51.5% (CI, 29.3% - 70.0%). Adverse events at least possibly related to vistusertib with frequency > 10% include nausea (54%); fatigue (36%); hypophosphatemia (29%); diarrhea, anorexia, dry mouth, and hypertriglyceridemia (all 14%); hypertension, vomiting, increased ALT, constipation, and weight loss (all 11%). Conclusions: Vistusertib treatment was associated with a PFS-6 rate that exceeds the RANO target of 35% for recurrent high-grade meningioma. The follow-up data continue to mature. Adverse events were tolerable in this patient population. Correlative studies to identify biological factors that correlate with response are under way. These data support the initiation of larger randomized studies of vistusertib in this setting. Clinical trial information: NCT03071874.

A phase 1 study of neoadjuvant chemotherapy followed by concurrent chemoradiation with gemcitabine, sorafenib, and vorinostat in pancreatic cancer.

e16268 Background: The multi-kinase inhibitor sorafenib (S) and HDAC inhibitor vorinostat (V) demonstrated synergism against preclinincal pancreatic cancer (PaCa) models. The combination of S & V also potently radiosensitized pancreatic cancer cells and enhanced the activity of gemcitabine (G). This led to a phase 1 trial to determine the doses and schedule appropriate for phase 2 study of S & V with weekly G and intensity modulated radiotherapy (IMRT) as neoadjuvant treatment of PaCa following chemotherapy. Methods: Using a 3+3 dose-escalation design, adult patients with resectable, borderline resectable, unresectable, and lymph node positive PaCa were enrolled to 6 dose levels. Enrolled patients had completed at least 8w of neoadjuvant chemotherapy prior to IMRT. The schedule of administration was weekly 200mg/m2 G weekly during IMRT, S & V were dosed either 3x or 5x weekly during IMRT. Primary endpoint was to identify the dose and schedule for S & V with G based chemoradiation. Key secondary endpoints included antitumor activity, R0 resection rate, OS. Correlative studies to evaluate a variety of biomarkers and Nanostring expression analysis on pre- and post-therapy tumor specimens were also performed. Results: 22 patients were enrolled and 21 treated at 6 dose levels. Due to thrombocytopenia limiting drug exposure, the trial was modified to reduce G to 200mg/m2/wk and S & V to 3 d/wk instead of 5 d/wk. 13 patients were eligible for surgery, and 9 had R0 resections. Conclusions: Our findings indicate that the study regimen was well tolerated, typical toxicities of S (hand foot syndrome) were not observed with intermittent dosing. Uncomplicated cytopenias limited drug exposure, which was improved with intermittent S&V dosing. The RP2D of the combination is S (400mg po BID 3d/wk), V (200mg po qd 3d/wk), G 200mg/m2 IV weekly, with IMRT (50.4 Gy over 28 fractions, 5d/wk). Antitumor activity was observed across dose levels, with an encouraging R0 resection rate. These results warrant further investigation of combining S and V with G and IMRT as neoadjuvant treatment of PaCa following chemotherapy. Analyses of correlative studies and OS are underway. Clinical trial information: NCT02349867. [Table: see text]