Citations

Abstract Traditional Hardy–Weinberg equilibrium (HWE) tests (the χ2 test and the exact test) have long been used as a metric for evaluating genotype quality, as technical artifacts leading to incorrect genotype calls often can be identified as deviations from HWE. However, in data sets composed of individuals from diverse ancestries, HWE can be violated even without genotyping error, complicating the use of HWE testing to assess genotype data quality. In this manuscript, we present the Robust Unified Test for HWE (RUTH) to test for HWE while accounting for population structure and genotype uncertainty, and to evaluate the impact of population heterogeneity and genotype uncertainty on the standard HWE tests and alternative methods using simulated and real sequence data sets. Our results demonstrate that ignoring population structure or genotype uncertainty in HWE tests can inflate false-positive rates by many orders of magnitude. Our evaluations demonstrate different tradeoffs between false positives and statistical power across the methods, with RUTH consistently among the best across all evaluations. RUTH is implemented as a practical and scalable software tool to rapidly perform HWE tests across millions of markers and hundreds of thousands of individuals while supporting standard VCF/BCF formats. RUTH is publicly available at https://www.github.com/statgen/ruth.

Abstract Background Accumulated evidence supports the existence of sex-associated differences in immune systems. Understanding the role of sex in immune-related adverse events (irAEs) is important for management of irAE in patients receiving immunotherapy. Methods We performed meta-analysis on published clinical study data and multivariable logistic regression on pharmacovigilance data and applied a propensity algorithm to The Cancer Genome Atlas omics data. We further validated our observations in 2 independent in-house cohorts of 179 and 767 cancer patients treated with immune checkpoint inhibitors. Results A meta-analysis using 13 clinical studies that reported on 1096 female patients (36.8%, 95% confidence interval [CI] = 35.0% to 38.5%) and 1886 male patients (63.2%, 95% CI = 61.5% to 65.0%) demonstrated no statistically significant irAE risk difference between the sexes (odds ratio [OR] = 1.19, 95% CI = 0.91 to 1.54, 2-sided P = .21). Multivariable logistic regression analysis of 12 225 patients from the Food and drug administration Adverse Event Reporting System (FAERS) and 10 979 patients from VigiBase showed no statistically significant difference in irAEs by sex. A propensity score algorithm used on multi-omics data for 6019 patients from The Cancer Genome Atlas found no statistically significant difference by sex for irAE-related factors or pathways. The retrospective analysis of 2 in-house patient cohorts validated these results (OR = 1.55, 95% CI = 0.98 to 2.47, false discovery rate = 0.13, for cohort 1; OR = 1.16, 95% CI = 0.86 to 1.57, false discovery rate = 0.39, for cohort 2). Conclusions We observed minimal sex-associated differences in irAEs among cancer patients who received immune checkpoint inhibitor therapy. It may be unnecessary to consider sex effects for irAE management in clinical practice.

Abstract Introduction Treatments for Peyronie's disease (PD) include surgical management and collagenase clostridium histolyticum (CCH). Aims To evaluate PD treatment trends after CCH approval and compare clinical outcomes in CCH- and surgery-treated cohorts. Methods Patients newly diagnosed with PD between January 2011 and December 2017 were identified in a U.S. claims database. Cohorts initiating treatment with CCH or surgery between January 2014 and June 2017 were included. Patients were continuously enrolled ≥6 months before and ≥12 months after index date. Post-treatment penile complications and analgesic use were compared 1 year after procedure in propensity score-matched cohorts. Main outcome measures The main outcome measures of this study were treatment patterns, penile complications, and analgesic use. Results In the newly diagnosed PD cohort, 1,609 patients received CCH and 1,555 patients had surgery. Overall CCH or surgery treatment rate/year increased from 9.8% in 2014 to 15.5% in 2017, with <1% receiving verapamil or interferon. Initial treatment ratios of CCH to surgery increased from approximately 1:1 (2014) to 2:1 (2017). In the unmatched CCH (n = 1,227) and surgery (n = 620) cohorts, more (P < .05) surgery-treated patients received analgesics (particularly opioids), oral PD therapies, vacuum erection devices, and phosphodiesterase-5 inhibitors before the index date. After propensity score matching (n = 620/cohort), newly occurring postprocedural complications during the follow-up period were higher in the surgery cohort (25.3% vs 18.4%, P = .003). The surgery cohort had significantly (P < .05) higher rates of erectile dysfunction (65.0% vs 44.8%), penile pain (17.9% vs 8.9%), and penile swelling (8.1% vs 5.2%) and was more likely to be prescribed opioids (93.3% vs 38.9%; P < .0001) or non-steroidal anti-inflammatory drugs (27.0% vs 20.3%; P = .006). Conclusion CCH demonstrated fewer complications and less analgesic use than surgery and was used as the initial therapy for PD twice as often as surgery.

AbstractIntroductionHypoalbuminemia is a known adverse prognostic factor in lymphomas. Yet, it is unknown if axicabtagene ciloleucel (axi‐cel) overcomes the adverse prognostic impact of hypoalbuminemia in relapsed/refractory large B‐cell lymphoma.MethodsWe conducted a retrospective analysis across three Mayo Clinic centers to assess the relationship of hypoalbuminemia (defined as a serum albumin (SA) levels ≤ 3.5 g/dL) on outcomes of patients treated with axi‐cel.ResultsThis analysis included 81 patients. Two patients had no available SA levels preceding axi‐cel infusion. Eighteen patients (22.8%) had hypoalbuminemia with a median SA of 3.3 g/dL. Patients with normal SA had a statistically higher ORR than those without hypoalbuminemia (P = .018). There was no difference in 1‐year PFS and OS between the group with hypoalbuminemia and the group with normal SA levels (48% vs 49%, P = .81) and (74% vs 73%, P = .97), respectively. There was no difference in the severity or median duration of cytokine release syndrome or neurotoxicity between the two groups.ConclusionNotwithstanding the limitations related to the relatively small sample size, axi‐cel therapy appears to overcome the adverse effect of hypoalbuminemia on OS and PFS. Large multicenter clinical studies are certainly needed to validate these findings.

AbstractBackgroundEpidemiological studies have demonstrated a positive association between chronic lymphocytic leukaemia (CLL) and non-melanoma skin cancer (NMSC). We hypothesized that shared genetic risk factors between CLL and NMSC could contribute to the association observed between these diseases.MethodsWe examined the association between (i) established NMSC susceptibility loci and CLL risk in a meta-analysis including 3100 CLL cases and 7667 controls and (ii) established CLL loci and NMSC risk in a study of 4242 basal cell carcinoma (BCC) cases, 825 squamous cell carcinoma (SCC) cases and 12802 controls. Polygenic risk scores (PRS) for CLL, BCC and SCC were constructed using established loci. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).ResultsHigher CLL-PRS was associated with increased BCC risk (OR4th-quartile-vs-1st-quartile = 1.13, 95% CI: 1.02–1.24, Ptrend = 0.009), even after removing the shared 6p25.3 locus. No association was observed with BCC-PRS and CLL risk (Ptrend = 0.68). These findings support a contributory role for CLL in BCC risk, but not for BCC in CLL risk. Increased CLL risk was observed with higher SCC-PRS (OR4th-quartile-vs-1st-quartile = 1.22, 95% CI: 1.08–1.38, Ptrend = 1.36 × 10–5), which was driven by shared genetic susceptibility at the 6p25.3 locus.ConclusionThese findings highlight the role of pleiotropy regarding the pathogenesis of CLL and NMSC and shows that a single pleiotropic locus, 6p25.3, drives the observed association between genetic susceptibility to SCC and increased CLL risk. The study also provides evidence that genetic susceptibility for CLL increases BCC risk.

Abstract Background: Disseminated tumor cells (DTCs) in bone marrow detected after treatment may represent occult residual disease. We enumerated DTCs after neoadjuvant chemotherapy (NACT) in patients (pts) diagnosed with high-risk early stage breast cancer and examined the relationship of these cells with response and survival. Methods: I-SPY SURMOUNT is a sub-study of the I-SPY 2 TRIAL (NCT01042379). Pts enrolled on I-SPY 2, who signed consent for this sub-study, had bone marrow aspirates (BMA) collected after NACT at the time of surgery. DTCs were isolated and enumerated from BMA using immunomagnetic enrichment/flow cytometry (IE/FC). DTCs were defined as EPCAM-positive and CD45-negative nucleated cells. Samples were considered positive using a predetermined threshold of >4 DTCs per mL (Magbanua et al, unpublished data). Pathologic response was assessed using the residual cancer burden (RCB) method at local sites, and pts underwent standard adjuvant therapy if indicated and follow up for recurrence events and death. Relationship of DTCs with clinicopathologic variables was examined using Chi-squared test. Group means were compared using t tests. The log-rank test was used to compare survival curves. Results: A total of 73 patients were enrolled, 51 of whom had successful DTC assessment. The median DTC per mL was 4 (interquartile range 1.2-11.6). 24/51 (47%) were DTC-positive. Clinical characteristics by DTC status are shown in the table. DTC-positive pts were significantly younger (p=0.02) and had larger pretreatment tumors (longest diameter by magnetic resonance imaging) compared to DTC-negative pts (p=0.032). DTCs were not associated with receptor subtype. Thirty pts (41%) achieved a pathologic complete response (pCR). DTCs were not associated with pCR (p= 0.166); however, DTC-positive patients were significantly more likely to have residual cancer (RCB-II/III) after NACT compared to DTC-negative patients (OR 3.3, p=0.037). Median follow up of this cohort was 2.8 years (range: 0.9-4.8). Interim survival analysis showed that DTCs were not significantly correlated with EFS (p=0.6) or DRFS (p=0.41). Conclusions: Detection of DTCs at surgery after NACT is significantly more common in young patients, those with larger tumors, and those with residual disease at surgery. While these associations suggest higher risk for later recurrence, larger studies and longer follow up are necessary to determine if DTCs add prognostic value over pathologic evaluation alone for pts receiving NACT. Citation Format: Mark Jesus M Magbanua, Laura van 't Veer, Amy Clark, A. Jo Chien, Judy Boughey, Heather Han, Anne Wallace, Heather Beckwith, Minetta Liu, Christina Yau, E. Paul Wileyto, Lamorna Brown Swigart, Jane Perlmutter, Lauren Bayne, Shannon Deluca, Stephanie Yee, Erica Carpenter, Laura Esserman, John Park, Lewis Chodosh, Angela DeMichele. Outcomes associated with disseminated tumor cells at surgery after neoadjuvant chemotherapy in high-risk early stage breast cancer: The I-SPY SURMOUNT study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-07.

Abstract Background: I-SPY 2 is a multicenter, phase 2 trial using response-adaptive randomization within molecular subtypes defined by receptor status and MammaPrint (MP) risk to evaluate novel agents as neoadjuvant therapy for women with high-risk stage II/III breast cancer. The primary endpoint is pathologic complete response (pCR, ypT0/Tis ypN0). SGN-LIV1A is an investigational antibody drug conjugate consisting of an antibody to LIV1A, a zinc transporter highly prevalent in breast cancer, and a highly potent microtubule inhibitor, monomethyl auristatin E. Retrospective IHC analysis of LIV1A expression levels amongst tumor samples from 100 previous ISPY-2 patients showed 88% of breast tumor samples with moderate to high expression of LIV1A (Yau, C. et al SABCS 2018).Methods: Women with tumors ≥ 2.5cm were eligible for screening. Only HER2 negative (HER2-) patients were eligible for this treatment, hormone-receptor positive (HR+) patients had to have MP high molecular profile. Treatment included SGN-LIV1A 2.5 mg/kg (max dose 250 mg) every 3 weeks x 4, followed by doxorubicin/cyclophosphamide (AC) every 2-3 weeks x 4. The control arm was weekly paclitaxel x 12 followed by AC every 2-3 weeks x 4. All patients undergo serial MR imaging where response at 3 & 12 weeks combined with accumulating pCR data are used to estimate, and continuously update, predicted pCR rate for the trial arm. Analysis set was modified intention to treat with patients who switched to non-protocol therapy counted as non-pCR and not as their pCR status at time of surgery. The goal is to identify/graduate regimens with ≥85% Bayesian predictive probability of success (i.e. demonstrating superiority to control) in a future 300-patient phase 3 neoadjuvant trial with a pCR endpoint within signatures defined by HR & HER2 status & MP result. This investigational arm was eligible for graduation in 3 of 10 pre-defined signatures: HER2-, HR+HER2- and HR-HER2-. Regimens may also leave the trial for futility (< 10% probability of success), maximum sample size accrual (10% < probability of success <85%), maximum time in trial (2 years) or for safety as recommended by the independent DSMB. Results: Sixty patients were randomized and evaluable to SGN-LIV1A. The study arm was stopped due to reaching the predetermined time limit for patient accrual of 2 yrs. Final estimated pCR rates are below. The estimated pCR rates were similar between the SGN-LIV1A and control arms for any tumor subtype. Preliminary safety events for SGN-LIV1A include increased rates of transaminitis and hyperglycemia and reduced rates of peripheral neuropathy compared to control. One patient was removed from the analysis as she was determined to have angiosarcoma of the breast. Notably, this patient had a dramatic early response and subsequent pCR to SGN-LIV1A treatment. Conclusion: The value of I-SPY 2 is to give insight about the performance of an investigational agent’s likelihood of achieving pCR. SGN-LIV1A delivered every 3 weeks was comparable to paclitaxel for the primary endpoint of pCR in I-SPY2 and may have a similar side effect profile, however, with less peripheral neuropathy. Clinical trials evaluating weekly dosing of SGN-LIV1A are ongoing. A trial of SGN-LIV1A in the treatment of angiosarcoma is under consideration at this time. Final Estimated pCR Rates and Predictive ProbabilitiesEstimated pCR rate(95% prob interval)SignatureSGN-LIV1AControlProbability SGNLIV1A Superior to ControlPredictive Probability of Success in Phase 3HER2-0.16 (0.08-0.24) N= 600.20 (0.16-0.25) N= 3270.180.02HR-/HER2-0.25 (0.12-0.37) N=360.28 (0.21-0.35) N=1460.310.06HR+/HER2-0.09 (0-0.18) N=240.14 (0.09-0.19) N=1810.150.03 Citation Format: Heather Beckwith, Richard Schwab, Christina Yau, Erica Stringer-Reasor, Shi Wei, A. Jo Chien, Kathy S Albain, Kevin Kalinsky, Anne Wallace, Anthony Elias, Douglas Yee, Amy S Clark, Judy C Boughey, Heather Han, Rita Nanda, Claudine Isaacs, Zahi Mitri, Julie E Lang, Alexandra Thomas, Tara Sanft, Angela DeMichele, Jane Perlmutter, Hope S Rugo, Nola M Hylton, W. Fraser Symmans, Michelle E Melisko, Laura J van't Veer, I-SPY 2 Consortium, Amy Wilson, Smita M Asare, Ashish Sanil, Donald A Berry, Laura J Esserman. Evaluation of SGN-LIV1a followed by AC in high-risk HER2 negative stage II/III breast cancer: Results from the I-SPY 2 TRIAL [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD1-10.

Introduction: Interleukin-1 receptor-associated kinase 4 (IRAK4) is essential for toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling in immune cells including B lymphocytes. It forms the Myddosome complex with the MYD88 adaptor protein, with IRAK4 being essential for downstream signaling, maximal activation of NFkB with inflammatory and immune response and tumor promotion [Treon 2012; Rhyasen 2015]. CA-4948 is a novel small molecule, oral inhibitor of IRAK4, first-in-class and only suppressor of the TLR pathway currently tested in hematological malignancies. When combined with the BTK inhibitor ibrutinib that blocks parallel BCR signaling and NF-kB activating pathway, it has shown synergy in in-vivo B-cell NHL models, providing strong rationale for clinical evaluation [Booher 2018]. Recent preclinical studies demonstrated the role of IRAK4 activation as a driver of secondary, adaptive tumor resistance and survival mechanisms of hematological and solid tumor malignancies [Melgar 2019] that could be blocked by CA-4948 to delay or reverse resistance. Study Design and Methods: This is a multicenter, open-label trial of oral CA-4948 combined with ibrutinib in adult patients with relapsed or refractory hematologic malignancies. (NCT03328078). It has 2 parts: a dose escalation (Part A2), and expansion basket of 4 cohorts (Part B). Part A2: Is a truncated 3+3 design: CA-4948 starting is 200 mg BID with subsequent escalation to 300 mg BID. Both dose are safe and active against NHL as seen in the nearly completed monotherapy Part A1 of this trial Patients will receive CA-4948 with ibrutinib at the labeled dose for the respective NHL subtype (560 mg or 420 mg) until toxicity or progression. Primary objectives are safety/tolerance (MTD, RP2D); 2nd objectives are pharmacokinetics and preliminary efficacy; exploratory objectives include biomarker correlations (e.g., MYD88-L265P mut, IRAK4 pathway, NFκB inhibition). Part B basket has four cohorts: 1 -MZL, 2 - ABC-DLBCL, 3 - PCNSL, and 4 - NHL with adaptive ibrutinib resistance. Cohorts 1-3 must be BTK-inhibitor naïve. Cohort 4 includes ibrutinib treated NHLs after developing adaptive, secondary resistance. All will receive the combination of ibrutinib and CA-4948. Cohort 4 patients will be allowed a <3 weeks gap since prior ibrutinib therapy. Primary objectives include CR or ORR and DOR compared to (matched) historical controls (closely matched if possible). 2nd objectives include tolerance/safety, PFS, and pop-PK sampling for CA-4948. Exploratory objectives; response correlation with biomarkers including MYD88-L265P or other genetic mutations, gene expressions, cell of origin, IRAK4 signaling, and resistance. Treatment: CA-4948 at RP2D+ibrubinib at labelled doses; 21-day cycles to be repeated in the absence of toxicity or progression. Samples sizes, statistical considerations: Approx. 18 patients in Part A2. In Part B, a Simon 2-Step design will be applied to each cohort. Early stopping rule for futility after approx. 20 patients in Stage 1: full accrual with Stage 2 will add about 25 patients. Successful signal efficacy identification in a cohort may support further expansion or a subsequent controlled trial. The safety population will include all patients in the study who received any test dose. The efficacy population will have a valid baseline and post-baseline disease assessment. Safety assessments include TEAEs, safety labs, vitals, physical exams, PK, and ECGs; efficacy assessments: tumor imaging, para-protein determination, and histo/cyto-morphologic examinations. Part A2 inclusion: Histopathologically confirmed B-cell NHL as per the WHO 2016 classification. Eligible NHL subtypes: FL, MZL, MCL, DLBCL (including extranodal lymphomas of leg, testicle, or other sites, excluding mediastinal lymphoma), CLL/SLL, primary or secondary CNS lymphoma, and WM/LPL. Patients with FL, MCL, MZL, WM/LPL, or CLL/SLL should meet clinical treatment criteria. Part B inclusion: Cohorts 1-3 include patients with MZL, ABC-DLBCL, or PCNSL who are BTK-inhibitor naïve. Cohort 4 will include ibrutinib pre-treated MCL, MZL, CLL/SLL, WM/LPL, ABC-DLBCL, or PCNSL with adaptive resistance. Exclusions for both Parts A2 and B: Significant acute or chronic toxicity from prior anti-cancer therapy that has not resolved to Grade ≤ 1, as determined by NCI CTCAE v 4.03 within 7 days prior to start of study or serious co-morbidities. Disclosures Nowakowski: NanoString: Research Funding; Seattle Genetics: Consultancy; Curis: Consultancy; Kymera: Consultancy; Kite: Consultancy; Celgene/BMS: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding; Ryvu: Consultancy, Membership on an entity's Board of Directors or advisory committees. Leslie:TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; KitePharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Speakers Bureau; Pharmacyclics/Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Epizyme: Speakers Bureau; Karyopharm: Speakers Bureau; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Joffe:AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees. Lunning:Kite: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; TG Therapeutics: Research Funding; Verastem: Consultancy, Honoraria; Acrotech: Consultancy; ADC Therapeutics: Consultancy; Legend: Consultancy; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Curis: Research Funding; Gilead: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Aeratech: Consultancy, Honoraria; Bristol Meyers Squibb: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria. Patel:Adaptive Biotechnologies: Consultancy; Kite: Consultancy; BeiGene: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau. Landsburg:Takeda: Research Funding; Triphase: Research Funding; Seattle Genetics: Speakers Bureau; Morphosys: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Curis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Fenske:Medical College of Wisconsin: Current Employment. Ramchandren:Merck, Seattle Genetics, Janssen, Genentech: Research Funding; Seattle Genetics, Sandoz-Novartis, Pharmacyclics, an AbbVie Company, Janssen, Bristol-Myers Squibb: Consultancy. Skarbnik:Alexion: Consultancy; Beigene: Speakers Bureau; Verastem: Speakers Bureau; CLL Society: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Tun:Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Mundipharma: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding; Acrotech: Research Funding; DTRM Biopharma: Research Funding.

Introduction CA-4948 is a novel oral small molecule inhibitor of interleukin-1 receptor-associated kinase 4 (IRAK4). IRAK4 is part of the Myddosome signaling pathway, and is essential for signaling downstream of toll-like receptors (TLR) and the interleukin-1 receptor (IL-1R) family in immune cells including B lymphocytes. . Dysregulated signaling in these pathways is frequently observed in Non-Hodgkin Lymphomas (NHL), particularly in ABC-subtype of Diffuse Large B-Cell Lymphoma (DLBCL) and Waldenström macroglobulinemia (WM)[1]. Furthermore, IRAK4 activation has recently been identified as a driver of an adaptive resistance mechanism of malignancies [2]. CA-4948 is the first clinical candidate targeting IRAK4 to be evaluated in cancer patients. Here we present Phase I results of CA-4948 in patients with relapsed/refractory hematologic malignancies. Method CA-4948-101 is a phase I trial dose escalation trial with a 3 + 3 design. Seven dosing cohorts were assessed including 50 and 100 mg daily (QD), and 50, 100, 200, 300, or 400 mg twice daily (BID) continuous oral monotherapy in 21-day cycles. Objectives included safety and tolerance (primary), pharmacokinetic (PK), pharmacodynamics (PD) and early efficacy (secondary), and biomarker correlations (exploratory). As of July 2020, 30 patients with relapsed or refractory, NHL have been enrolled, including DLBCL (n=14), FL (n=6), transformed HGBL (n=1), WM (n=3), LPL (n=2), MZL (n=2) and MCL (n=2). Median age is 68.5 (range 50 - 87; 5 female / 25 male). Median number of prior treatments is 4 (range 1 - 8, incl. 5 CAR-T-cell or ASCT treatments). Results CA-4948 has been generally well tolerated. Eight patients were exposed at the highest dose level of 400 mg BID: 2 of 5 DLT-evaluable patients had Grade 3 rhabdomyolysis (DLTs), without complications and reversible after treatment interruption and hydration / analgesic treatment - both subsequently continued treatment at lower doses of 200 or 300 mg BID, respectively. Six patients have tolerated 300 mg BID well without DLT. Most non-hematologic TEAEs were Grade 1 or 2 and manageable, including diarrhea, vomiting, fatigue, dyspnea, and myalgia. Hematologic TEAEs including neutropenia, anemia, thrombocytopenia was mild/moderate and without complications. There were only 4 Grade 3 combined episodes in 18 patients at dose levels ranging between 200 and 400 mg BID without complications (Table 1). Drug discontinuation occurred in only 3 cases for rash, fatigue, and asymptomatic amylase/lipase elevation at lower dose levels. No toxic deaths occurred. Favorable and predictable PK characteristics included rapid absorption with Tmax at 2-3 hours, T1/2 of 6 hours (supporting bid dosing), moderate accumulation, and dose-proportional increases in exposure. Dose proportional PD changes were shown for inflammatory cytokine reductions. Treatment duration ranged between 15 days and 19+ months with sustained disease control. Eight of 28 evaluable patients experienced overall tumor burden decreases of ≥20% from baseline - more at higher doses (Table 2). A WM patient with 6 prior lines of treatment, sustained PR underwent intra-patient dose escalation and had a dose/response relationship and very good treatment tolerance (Figure 1). The median duration at doses of 200 or 300 mg bid was >6 months (range 1-19+; including 3 cases of 11, 14, and 19+ mo.). Downstream pharmacodynamic markers of IRAK4 and molecular characteristics including cell-of-origin will be presented. Conclusion CA-4948 demonstrates good safety profile, desirable pharmacokinetic properties, and preliminary clinical activity. Enrollment is ongoing to support the anticipated RP2D of 300 mg bid. These encouraging results provide clinical validation of IRAK4 as a viable, novel therapeutic target in B-cell malignancies will lead to clinical combinations with synergistic drugs including BTK or BCL2 inhibitors [3] in patients with advanced hematological malignancies. Clinical trial: NCT03328078. References: 1. Treon, S. P. et al., 2012. N Engl J Med, 367: 826-33 2. Melgar, K. et al., 2019. Sci Transl Med, 11: eaaw8828 3. Booher R, Grayson D., 2019. Waldenstrom Roadmap Symposium, www.Curis.com Disclosures Nowakowski: Curis: Consultancy; MorphoSys: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Kite: Consultancy; Ryvu: Consultancy, Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; Kymera: Consultancy; Seattle Genetics: Consultancy. Leslie:TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria, Speakers Bureau; Epizyme: Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Honoraria, Speakers Bureau; KitePharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; Celgene: Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Younes:Curis: Consultancy; Daiichi Sankyo: Consultancy; HCM: Consultancy; Epizyme: Consultancy; Takeda: Consultancy; Novartis: Consultancy; BioPath: Consultancy; BMS: Consultancy; Janssen: Consultancy; AstraZeneca: Current Employment. Lunning:Gilead: Consultancy, Honoraria; Curis: Research Funding; Beigene: Consultancy, Honoraria; Aeratech: Consultancy, Honoraria; Bristol Meyers Squibb: Consultancy, Honoraria, Research Funding; Kite: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; Legend: Consultancy; ADC Therapeutics: Consultancy; Acrotech: Consultancy; Verastem: Consultancy, Honoraria; TG Therapeutics: Research Funding. Patel:Celgene/BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy; BeiGene: Consultancy; Pharmacyclics: Consultancy, Speakers Bureau; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Kite: Consultancy; Genentech: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau. Landsburg:Takeda: Research Funding; Seattle Genetics: Speakers Bureau; Morphosys: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Curis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Triphase: Research Funding. Tun:Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Mundipharma: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding; Acrotech: Research Funding; DTRM Biopharma: Research Funding.