Carvajal, Richard D.

With improved medical treatments, the prognosis for many malignancies has improved, and more patients are presenting for transplant evaluation with a history of treated cancer. Solid organ transplant (SOT) recipients with a prior malignancy are at higher risk of posttransplant recurrence or de novo malignancy, and they may require a cancer surveillance program that is individualized to their specific needs. There is a dearth of literature on optimal surveillance strategies specific to SOT recipients. A working group of transplant physicians and cancer-specific specialists met to provide expert opinion recommendations on optimal cancer surveillance after transplantation for patients with a history of malignancy. Surveillance strategies provided are mainly based on general population recurrence risk data, immunosuppression effects, and limited transplant-specific data and should be considered expert opinion based on current knowledge. Prospective studies of cancer-specific surveillance models in SOT recipients should be supported to inform posttransplant management of this high-risk population.

2549 Background: BDC-1001 is a novel ISAC consisting of an investigational trastuzumab biosimilar chemically conjugated to a TLR 7/8 agonist with a non-cleavable linker. BDC-1001 was designed to activate the innate immune system, eliciting antibody-mediated effector functions (eg, antibody-dependent cellular phagocytosis) and a durable adaptive immune response. In preclinical tumor models resistant to anti-HER2 treatments, BDC-1001 demonstrated potent and durable immune-mediated antitumor efficacy. Methods: A 4-part, phase 1/2 dose-escalation/expansion study was initiated to evaluate BDC-1001 ± PD1 inhibitor pembrolizumab in pts with HER2-expressing solid tumors who had progressive disease on standard of care (NCT04278144). Preliminary results of the monotherapy dose escalation (Part 1) are reported. Pts with advanced metastatic HER2-expressing (IHC2/3+) or amplified solid tumors received BDC-1001 IV q3w in a 3+3 design w/ 12 pts/cohort backfill allowed. Primary objectives were to evaluate safety, tolerability, dose-limiting toxicities (DLTs) and determine a phase 2 dose; secondary objectives were to assess pharmacokinetics (PK), pharmacodynamics and preliminary anti-tumor activity. Results: As of Jan 29, 2021, 20 pts w/ a median age of 65 (46-85) have enrolled in 4 dose levels (0.15mg/kg to 5 mg/kg). Cancer types include breast, biliary, cervical, colorectal (CRC), lung, gastroesophageal, salivary, urinary tract and endometrial. Pts had received a median of 4 (1-7) prior therapies; 65% received >1 prior anti-HER2 therapy. All pts completed the 21-day DLT period; no DLTs or drug-related serious adverse events (AEs) have been observed. AEs deemed related to BDC-1001 have been mild to moderate including infusion-related reactions. The MTD has not been reached (treatment duration 5-17+wk); enrollment is ongoing. PK evaluations showed Cmax levels consistent with predicted modeling based on non-human primates (NHP). One pt with microsatellite stable (MSS) HER2+ CRC with lung metastases had a confirmed partial response after 4 cycles and remains on study; 2 additional pts with metastatic MSS HER2+ CRC had stable disease (SD) and a pt with heavily pretreated MSS endometrial cancer with lung metastases had confirmed SD and remains on treatment 17+ wk; 3 of these pts had received 2 prior anti-HER2 therapies. Conclusions: In this first-in-human study, BDC-1001 appears to be well-tolerated up to the dose tested to date (5 mg/kg), with Cmax levels achieved as predicted by NHP modeling. Evidence of clinical activity have been observed, including in pts previously treated with anti-HER2 therapy. Dose escalation is ongoing and will be followed by combination dosing with CPI and the phase 2 component in selected tumors. Clinical trial information: NCT04278144.

CRA9003 The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Saturday, June, 1, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

CRA9003 Background: Gq/11 mutations are early oncogenic events in UM resulting in MAPK pathway activation. We demonstrated decreased viability in UM cell lines harboring Gq/11 mut with sel, a small molecule inhibitor of MEK1/2 (Ambrosini, CCR 2012). Methods: We conducted a 16 center randomized phase II study of hyd-sulfate sel 75 mg BID vs TMZ 150 mg/m2 daily for 5 days in 28-day cycles (or DTIC 1000 mg/m2 q21 days) for patients (pts) with metastatic UM with a Q209 Gq/11 mut who have not received prior TMZ/DTIC. The primary endpoint was progression free survival (PFS). Secondary endpoints included overall survival (OS) and response rate (RR). Select pts underwent tumor biopsies at baseline and after 14 (+/- 3 days) of sel. Our statistical plan required ≥80 pts randomized and ≥68 events to detect a PFS hazard ratio of 0.6 (p=0.1). Randomization was stratified by mut (Gq vs G11), M stage and number of prior therapies (tx). Tumor assessment occurred every 4 weeks (wks) for 8 wks and then every 8 wks using RECIST 1.1. Pts receiving TMZ who progressed could receive sel (TMZ→sel). Results: 80 pts were randomized. Sel (n=39): median age 66 (range 32-86), 54% male, 54% G11 mut, median ECOG PS 0 (range 0-1), 97% M1c, median prior tx 0 (range 0-2). TMZ (n=41): median age 60 (range 34-81), 63% male, 58% G11 mut, median ECOG PS 0 (range 0-1), 93% M1c, median prior tx 0 (range 0-2). 11/39 (28%) pts on sel experienced grade (gr) 3 toxicity (tox) manageable with dose modification (5 CPK elevation, 3 LFT elevation, 1 rash, 1 lymphopenia, 1 edema). 1/41 (2%) pt on TMZ experienced gr 3 tox (neutropenia). No gr 4/5 tox occurred. 28 pts on sel underwent paired tumor biopsies with inhibition of pERK and cyclinD1 observed by Western blot at day 14. At interim analysis (9/25/12), 55 pts were evaluable with 45 progression events and 16 deaths. Sel (n=27): median PFS 16 wks (95% CI 8-30.9), RR 11%, median OS 11.8 months (95% CI 4.8-not reached). TMZ (n=28): median PFS 4 wks (95% CI 3.7-15), RR 0%, median OS 4.7 months (95% CI 4.3-14.3). TMZ→sel (n=25): median PFS 8.1 wks (95% CI 7-15), RR 0%. Conclusions: Sel is the first drug to ever show improved clinical activity in UM relative to TMZ. Sustained target inhibition is observed with sel. Final results will be presented. Clinical trial information: NCT01143402.