Citations

9002 Background: KRAS is a key mediator of the RAS/MAPK signaling cascade that promotes cellular growth and proliferation. KRASG12C mutation occurs in ̃14% of NSCLC. Adagrasib, an investigational agent, is a KRASG12C inhibitor that irreversibly and selectively binds KRASG12C, locking it in its inactive state. Adagrasib is optimized for favorable pharmacokinetic (PK) properties, including long half-life (̃24 h), dose-dependent PK, and central nervous system penetration; it has demonstrated objective response and favorable tolerability in the Phase 1/1b setting. Methods: KRYSTAL-1 (NCT03785249) is a multicohort Phase 1/2 study evaluating adagrasib as monotherapy or in combination regimens in patients with advanced solid tumors harboring a KRASG12C mutation. Here we report the first disclosure from all patients enrolled in Cohort A, a Phase 2 cohort with registrational intent, evaluating adagrasib given 600 mg orally BID in patients with NSCLC previously treated with platinum-based chemotherapy and anti-PD-1/L1 therapy. Study objectives include evaluating efficacy (objective response rate [ORR], duration of response [DOR], progression-free survival [PFS], overall survival [OS]), safety, PK, and exploratory correlative analyses. Objective tumor response was assessed per RECIST v1.1 by blinded independent central review (BICR). Results: As of the 15 October 2021 data cutoff, 116 patients with NSCLC harboring a KRASG12C mutation were enrolled and treated, with a median follow-up of 12.5 months. Baseline characteristics include median age 64 years, 65% female, and 15.5%/83.6% with ECOG PS 0/1; 98.3% of patients received adagrasib following prior treatment with immunotherapy and chemotherapy, with a median of 2 prior systemic therapies. The ORR (by BICR) was 42.9% (48/112) and the disease control rate was 79.5% (89/112); 31 patients remain on treatment. Median DOR was 8.5 months (95% CI 6.2–13.8), median PFS was 6.5 months (95% CI 4.7–8.4), median OS was 12.6 months (95% CI 9.2–NE). Treatment-related AEs (TRAEs) of any grade occurred in 97.4% of patients, grade ≥3 TRAEs in 45.7%, 2 grade 5 TRAEs, and 8 (6.9%) TRAEs led to discontinuation. The most commonly reported (≥25%) TRAEs (any grade) were diarrhea (62.9%), nausea (62.1%), vomiting (47.4%), fatigue (40.5%), ALT/AST increased (27.6%/25%), blood creatinine increased (25.9%); the most commonly reported (≥5%) TRAEs (grade 3/4) were lipase increased (6%) and anemia (5.2%). Additional subgroup analyses will be presented, including selected demographics, molecular markers and sites of metastases. Conclusions: Adagrasib is well tolerated and demonstrates promising efficacy in pretreated patients with NSCLC harboring a KRASG12C mutation. A Phase 3 trial evaluating adagrasib monotherapy versus docetaxel in previously treated patients with KRASG12C-mutant NSCLC is ongoing (NCT04685135). Clinical trial information: NCT03785249.

TPS8604 Background: Chemoimmunotherapy followed by durvalumab maintenance yields a median overall survival of 12.9 months in patients with extensive stage Small Cell Lung Cancer (ES SCLC), which is an improvement over chemotherapy alone. However, 90% of these patients will have progressive disease. While topotecan and lurbinectedin have established modest activity in the second line, it is unknown whether continuing immunotherapy in this setting confers additional benefit. In preclinical studies lurbinectedin, a DNA minor groove binder, used with immune checkpoint inhibitors has synergistic effects. Methods: This phase 2 trial is enrolling patients with ES SCLC who have progressed on platinum based chemoimmunotherapy, to three treatment groups. Group 1 includes patients with platinum sensitive SCLC who will receive durvalumab (1500 mg given as an intravenous [IV] infusion once every 3 weeks) and topotecan (1.25 mg/m2/day IV for 5 consecutive days every 3 weeks). In Groups 2A and 2B, patients with platinum sensitive and platinum resistant disease respectively, receive durvalumab and lurbinectedin (3.2 mg/m2 IV on Day 1 of every 21-day cycle). Patients with platinum sensitive disease are assigned to Groups 1 or 2A based on the preferences of the treating physician and the patient. Patients with treated/stable CNS metastases are eligible. The primary endpoint is the proportion of patients who are alive at 6 months (6OS) for Group 1 and the proportion of patients who are alive and progression-free at 6 months (6PFS) in Groups 2A and 2B. Secondary endpoints include safety, adverse event profile, response rate, PFS, and OS. The sample size is based on a 2-stage Simon Optimal Design. For Treatment Group 1, with 22 eligible patients there is 80% power to detect a true 6-month OS rate (6OS) of 75%, with 10% alpha under the null hypothesis that the true 6OS is at most 50%. For Treatment Group 2A, with 20 eligible patients this design has 80% power to detect a true 6-month PFS rate (6PFS) of 65%, with 10% alpha under the null hypothesis that the true 6PFS is at most 40%. For Treatment Group 2B, with 22 eligible patients this design has 80% power to detect a true 6-month PFS rate (6PFS) of 40%, with 10% alpha under the null hypothesis that the true 6PFS is at most 19%. To account for possible drop-outs, accrual targets will be 24, 22, and 24 patients to Groups 1, 2A, and 2B respectively. For the safety analyses, 6 patients will be enrolled at the starting dose level for each treatment group (1, 2) and then briefly closed to accrual to assess adverse events. If we observe 2+ DLTs in these 6 treated patients during Cycle 1 within a treatment group (1 vs. 2), we will declare the combination treatment too toxic and lower the starting dose of chemotherapy for the next 6 patients. The study was open for all 3 groups as of January 2022 and has accrued 2 patients. Clinical trial information: NCT04607954.

TPS8598 Background: Peritoneal mesothelioma is a rare and poorly studied disease with few treatment options. For patients who are not surgical candidates, treatment recommendations for systemic therapy have been extrapolated from clinical trials for pleural mesothelioma that commonly exclude patients with peritoneal mesothelioma. Recently, the combination of the PD-1 inhibitor nivolumab and the CTLA-4 inhibitor ipilimumab received FDA-approval for the frontline treatment of non-resectable pleural mesothelioma. Additionally, a prospective, non-randomized phase 2 trial demonstrated activity with combined PD-L1 (atezolizumab) and VEGF (bevacizumab) blockade in peritoneal mesothelioma. In parallel, encouraging activity with combined chemo-immunotherapy has been reported in pleural mesothelioma. Given the benefits observed with immunotherapy, and the potential to improve upon those with chemotherapy and VEGF inhibition, we seek to determine whether the addition of the PD-L1 inhibitor atezolizumab improves outcomes with chemotherapy and bevacizumab in patients with newly diagnosed peritoneal mesothelioma. Methods: A092001 is a prospective, randomized phase 2 clinical trial. All patients with newly diagnosed peritoneal mesothelioma will be randomized 1:1 using a dynamic allocation Pocock-Simon procedure to receive carboplatin, pemetrexed, and bevacizumab, with or without atezolizumab, every 21 days for four cycles. Patients who are eligible to proceed with surgery after four cycles of therapy will then do so. Patients who are not eligible to proceed with surgery may receive maintenance bevacizumab and atezolizumab, or second-line atezolizumab with bevacizumab until progression of disease or toxicity. The primary objective is to determine whether frontline treatment with carboplatin, pemetrexed, bevacizumab and atezolizumab results in a superior best response rate (RR) to carboplatin, pemetrexed and bevacizumab as determined by RECIST. With 31 eligible patients per arm (62 eligible total), this randomized design has 80% power to detect an improvement in the RR from 20% to 45%, with a 1-sided significance level of 0.10 where an interim futility analysis will be conducted after 32 patients are enrolled. As stratification factors we have included eligibility for cytoreductive surgery at diagnosis, and histologic subtype. Secondary endpoints include assessment of progression-free survival, overall survival, and adverse events. As integrated biomarkers, we will determine if soluble mesothelin-related peptides and megakaryocyte potentiating factor correlate with responses. This trial was recently approved by the National Cancer Institute Central IRB and is activating at sites across the country. Support: U10CA180821, U10CA180882. Clinical trial information: NCT05001880.

TPS6111 Background: Treatment options for recurrent and/or metastatic (R/M) salivary gland cancer (SGC) are limited with response rates to standard cytotoxic chemotherapy (CT) low at 10-30%, and responses to single-agent immune checkpoint inhibition (ICI) <10%. Current therapeutic agents used to treat R/M SGC have an unfavorable toxicity profile including cytotoxic CTs such as cisplatin and doxorubicin and the targeted therapy lenvatinib. Treatments with general applicability and acceptable side effect profile are urgently needed. Pemetrexed (PTX) is a multi-targeted anti-folate CT with an excellent safety and toxicity profile with promising responses reported in a case series of patients (pts) with R/M SGC (Viscuse P and Price K. Marked responses to pemetrexed chemotherapy for metastatic adenocarcinoma of the parotid gland: case series. Head Neck 2019;41(6):E99-103.). As the combination of PTX and pembrolizumab (PMB) showed enhanced responses and survival in pts with lung cancer, we hypothesize that PTX and PMB will have efficacy in pts with R/M SGC and that the combination will have improved anti-cancer activity compared with historical controls. Correlative studies on archived tissues include methylthioadenosine phosphorylase loss, PDL1 expression, and thymidylate synthase expression as potential biomarkers of response. Methods: MC200708 is a single institution (3-site), open-label, single arm phase II study of PTX and PMB in patients with R/M SGC. Pts will be treated in two cohorts: one for pts with adenoid cystic carcinoma (ACC) and the other for pts with all other types of SGC (non-ACC cohort). Eligible pts must be ≥18 years old, have a pathologically confirmed SGC that is not amenable to curative-intent therapy, ECOG 0-2, adequate organ function, and at least 1 measurable lesion by RECIST 1.1. Any number of lines of prior therapy is allowed; prior treatment with checkpoint inhibitors and/or PTX is allowed. Key exclusion criteria: serious medical co-morbidity or autoimmune disease, prior grade 3-4 adverse event (AE) or grade 2-4 lung AE with ICI, and uncontrolled brain metastases. Simon’s two-stage design will be used for each cohort separately given the expected difference in responses in pts with ACC and non-ACC. Primary endpoint is overall response rate. Secondary endpoints are progression free and overall survival and toxicity. All patients will receive the same treatment of PTX 500 mg/m2 IV + PMB 200 mg IV every 3 weeks until disease progression or treatment intolerance. Response assessments will occur every 3 cycles. Enrollment began July 2021 and 16 of the planned 45 patients (ACC cohort 9 of 20 pts, non-ACC 7 of 25) have been accrued. Clinical trial information: NCT04895735.

4023 Background: Metastatic pancreatic cancer (mPC) remains a deadly disease with very limited treatment options. FFX is a standard first-line therapy for mPC with a median overall survival (mOS) of 11.1 months. CPI-613 is a stable intermediate of a lipoate analog that inhibits pyruvate dehydrogenase and α-ketoglutarate dehydrogenase enzymes of the tricarboxylic cycle preferentially within the mitochondria of cancer cells. In a phase I study, CPI-613+mFFX was safe and exhibited promising signal of efficacy. Methods: A global, randomized phase 3 trial was conducted across 73 sites to investigate the efficacy and safety of CPI-613 in combination with mFFX compared to standard dose FFX in treatment-naïve patients with mPC. Treatment was administered in 2-weekly cycles until progression or intolerable toxicity. In the experimental arm, CPI-613 at 500 mg/m2 was given intravenously on days 1 and 3. The doses of irinotecan, oxaliplatin, and 5-fluorouracil in the experimental arm were 65 mg/m2, 140 mg/m2, and 2,400 mg/2, respectively. Primary endpoint was OS. Secondary endpoints were progression-free survival (PFS), overall response rate (ORR), duration of response, pharmacokinetics, patient reported outcomes and safety. Results: 528 patients were randomly assigned (266 in test and 262 in control arm). There were 362 deaths, with a mOS of 11.1 months for CPI-613+mFFX vs. 11.7 months for FFX [hazard ratio (HR), 0.95; 95% CI, 0.77 to 1.18; P = 0.655]; mPFS was 7.8 months vs. 8.0 months respectively [HR, 0.99; 95% CI, 0.76 to 1.29; P = 0.94]; ORR was 39% in the test arm vs. 34% in the control arm [ORR ratio, 1.23 (95% CI, 0.86 to 1.75)]. Grade ≥ 3 treatment-emergent adverse events with ≥ 10% frequency in CPI-613 plus mFFX vs. FFX arm were diarrhea (11.2% vs. 19.6%), hypokalemia (13.1% vs. 14.9%), anemia (13.9% vs. 13.6%), neutropenia (11.2% vs. 14.0%), thrombocytopenia (11.6% vs. 13.6%) and fatigue (10.8% vs. 11.5%). Conclusions: The addition of CPI-613 to mFFX failed to show significant improvements of ORR, PFS or OS. The mFFX in the test arm that had the lowest prospectively tested doses of FFX was without compromise on PFS or OS and may be considered as a reference for future FFX administration. Clinical trial information: NCT03504423.

3525 Background: Tumor-infiltrating lymphocytes (TILs) are significantly associated with clinical outcomes in patients with colon cancer. However, the potential for a differential effect of TILs on prognosis based on primary tumor sidedness has not been studied. We determined the interaction between TILs and tumor sidedness in relationship to disease-free survival (DFS). Methods: We analyzed data on TIL densities by primary tumor sidedness in 1532 stage III colon carcinomas from participants in a phase III trial of FOLFOX-based adjuvant chemotherapy (NCCTG N0147). TIL densities were dichotomized as low or high (≤3 /HPF) based on an optimized cutoff previously identified for DFS in this cohort. Right-sided tumors were defined as proximal to the splenic flexure. Analysis of TILs and sidedness with DFS were examined using Kaplan-Meier methodology and multivariable Cox regression. Results: Overall, tumors with high vs low TILs had the best DFS [HRadj: 0.58 (95%CI: 0.45-0.74); Padj <0.0001]. The association of TIL densities with 5-yr DFS differed significantly by primary tumor sidedness ( Pinteraction (adj) = 0.045). Among right-sided tumors, high vs low TILs were significantly associated with improved DFS ( Padj <0.0001)[Table]. Among left-sided tumors, however, DFS did not differ significantly for high vs low TILs ( Padj =0.173)[Table]. Similar results for TILs and DFS by sidedness were found for pMMR cancers. We then analyzed our data in low risk (T1-3, N1) and high risk (T4 and/or N2) tumors. Among low risk tumors, high vs low TILs was significantly associated with improved 5-yr DFS only in right-sided tumors ( Padj =0.006) [Table]. Among high risk tumors, high vs low TILs were significantly associated with better DFS in both right-sided ( Padj<0.001) and left-sided ( Padj =0.024) tumors. Conclusions: Overall, tumors with high TIL densities had significantly better DFS in right-sided but not left-sided cancers. Among low risk patients, the association of high TILs with better DFS was limited to right-sided tumors. These findings suggest that TILs should be interpreted by sidedness for prognostication. ClinicalTrials.gov Identifier: NCT00079274 . [Table: see text]

Abstract OBJECTIVE: We hypothesize that patients with neurocutaneous melanocytosis-associated melanoma and ventriculoperitoneal shunts are at risk of developing intraperitoneal spread of melanoma. BACKGROUND: Neurocutaneous melanocytosis, a rare condition characterized by excessive proliferation and deposition of melanocytes in the leptomeninges and brain parenchyma, typically occurs in children with large congenital melanocytic nevi and multiple smaller congenital nevi. These patients are at heightened risk for developing NRAS+ melanomas in the central nervous system, which in turn may lead to symptomatic hydrocephalus requiring cerebrospinal fluid diversion for symptom relief. METHODS: Retrospective single-institution study of patients with histologically or radiographically confirmed NCM evaluated at Memorial Sloan Kettering Cancer Center (MSKCC) from 2001-2022. RESULTS: Of the 47 patients with a diagnosis of NCM, 44 patients had symptomatic neurological complications. Eleven patients developed hydrocephalus, 10 had CNS melanoma, and required ventriculoperitoneal shunt placement. Nine of the 10 patients ultimately died of their disease. Three patients were diagnosed with intraperitoneal melanoma, though data are unavailable for the remaining eight. CONCLUSIONS: All (n=11) patients with NCM-associated CNS melanoma required VP shunts for symptomatic relief. Ten of these patients died within 4.3 years of VP shunt placement, with a range of 1 month to 13.5 years prior to succumbing to their disease. While the intraperitoneal pathology remains unknown for 7 of the cases, 3 had confirmed intraperitoneal melanoma, suggesting that VP shunts provided the conduit to CNS melanoma seeding of the peritoneum. Obtaining baseline abdominal imaging studies prior to VP shunt placement may be helpful in the follow-up of these patients.

Importance Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal adenomas and cancer. Combination sulindac and erlotinib was previously shown to reduce duodenal polyp burden but was associated with a relatively high adverse event (AE) rate. Objective: To evaluate if a once weekly dosing schedule for erlotinib intervention improves the AE profile, while still providing efficacy with respect to reduced polyp burden, in participants with FAP. Design, setting and participants: Single-arm trial, enrolling 46 participants with FAP, conducted from October 2017 to September 2019 in eight academic cancer centres. Exposures Participants self-administered 350 mg of erlotinib by mouth, one time per week for 6 months. Main outcomes and measures: Duodenal polyp burden (sum of polyp diameters) was assessed in the proximal duodenum by esophagogastroduodenoscopy performed at baseline and 6 months, with mean per cent change defined as the primary efficacy outcome of interest. Rate of grade 2–3 AEs was evaluated as a co-primary outcome. Secondary outcomes included changes in total duodenal polyp count, along with changes in lower gastrointestinal (GI) polyp burden and count (for participants examined by optional lower endoscopy). Results Forty-six participants (mean age, 44.1 years (range, 18–68); women, 22 (48%)) were enrolled; 42 participants completed 6 months of intervention and were included in the per-protocol analysis. Duodenal polyp burden was significantly reduced after 6 months of weekly erlotinib intervention, with a mean per cent change of −29.6% (95% CI, −39.6% to −19.7%; p<0.0001). Similar results were observed in subgroup analyses defined by participants with advanced duodenal polyposis (Spigelman 3) at baseline (mean, −27%; 95% CI, −38.7% to −15.2%; p<0.0001). Post-intervention Spigelman stage was downstaged in 12% of the participants. Lower GI polyp number was also decreased after 6 months of intervention (median, −30.8%; IQR, −47.4% to 0.0%; p=0.0256). Grade 2 or 3 AEs were reported in 71.7% of subjects, with only two experiencing grade 3 toxicity at least possibly related to intervention. Conclusion In this single-arm, multi-centre trial of participants with FAP, erlotinib one time per week resulted in markedly lower duodenal polyp burden, and modestly reduced lower GI polyp burden, after 6 months of intervention. While AEs were still reported by nearly three-quarters of all participants, these events were generally lower grade and well-tolerated. These findings support further investigation of erlotinib as an effective, acceptable cancer preventive agent for FAP-associated GI polyposis. Trial registration number NCT02961374 .

Abstract Cellular senescence contributes to tissue homeostasis and age-related pathologies. However, how senescence is initiated in damaged cells remains vague. Here, we discover that irreparable stresses induce transient biogenesis of cilia, which are used by stressed cells to directly communicate with the promyelocytic leukemia nuclear bodies (PML-NBs), the validated stress signaling hub, to initiate senescence responses. Mechanistically, a ciliary ARL13B-ARL3 GTPase cascade negatively regulates the association of transition fiber protein FBF1 and SUMO-conjugating enzyme UBC9. Irreparable stresses downregulate the ciliary ARLs to release UBC9, which SUMOylates FBF1 at the ciliary base. SUMOylated FBF1 then translocates to PML-NBs to promote PML-NB-dependent senescence initiation. Remarkably, Fbf1 suppression effectively subdues global senescence burden and prevents associated health-span decline in irradiation-treated mice. Collectively, our findings assign primary cilia a central role in inducing senescence program and identify them as promising targets to dampen senescence-associated detrimental damage in future senotherapy strategies.