Paz‐Ares, Luis

RET fusions appear in 1%-2% of non–small cell lung cancers (NSCLCs). The results from the ARROW study (ClinicalTrials.gov identifier: NCT03037385 ) supported US Food and Drug Administration approval of pralsetinib, an oral selective RET inhibitor, for metastatic RET -altered NSCLC and RET fusion–positive thyroid cancers. ARROW was a phase I/II open-label study of pralsetinib 400 mg once daily in RET fusion–positive NSCLCs. Coprimary end points were overall response rate (ORR) and safety. Key secondary end points included duration of response, progression-free survival, and overall survival (OS). At data lock (May 20, 2024), 281 patients initiated pralsetinib (median treatment duration, 15.0 months). ORR (measurable disease patients; n = 259) was 78% (95% CI, 69 to 86) for treatment-naïve patients and 63% (95% CI, 54 to 71) for prior platinum-based chemotherapy patients. Median OS was 44.3 months (95% CI, 30.9 to 53.1), 50.1 months (95% CI, 28.3 to not reached) in treatment-naïve patients, and 39.7 months (95% CI, 27.8 to 53.2) in prior platinum patients. Common grade ≥3 treatment-related adverse events were anemia (21%), hypertension (15%), and decreased neutrophils (13%). Three treatment-related deaths occurred (pneumonia, n = 2; interstitial lung disease and rhabdomyolysis, n = 1 each). Safety was consistent with previous ARROW reports; no hypersensitivity was reported in patients receiving prior immunotherapies. Pralsetinib produced robust, durable responses with manageable safety in treatment-naïve and previously treated patients with RET fusion–positive NSCLCs, confirming previous findings with longer follow-up.

8501 Background: TROPION-Lung02 (NCT04526691) evaluated the TROP2-directed antibody-drug conjugate (ADC) Dato-DXd plus pembro combination with or without Pt-CT in aNSCLC. Here we report primary analyses of pts receiving combination therapy in the 1L setting. Methods: Pts across 6 cohorts were dosed with Dato-DXd (4 or 6 mg/kg) plus pembro 200 mg alone (doublet) or with pembro plus Pt-CT (triplet; cisplatin 75 mg/m 2 or carboplatin AUC 5) Q3W. PD-L1 expression (tumor proportion score) was assessed locally by immunohistochemistry (22C3 assay). Primary objectives were safety and tolerability; efficacy was a secondary objective. Results: As of Apr 29, 2024, 96 pts received either the doublet (n=42) or triplet (n=54) combination as 1L therapy; 29% and 15% of pts were ongoing, respectively. Median ages were 65 (doublet) and 64 years (triplet). Median treatment durations were 9.7 and 5.8 months, respectively. Stomatitis (doublet, 57%; triplet, 33%) and nausea (doublet, 42%; triplet, 48%), primarily Gr 1–2, were the most common adverse events (AEs) across both regimens. Treatment related serious AEs occurred in 5 (12%) and 12 (22%) pts in each cohort and no deaths related to study drug were seen. Efficacy outcomes, including by histology, are summarized in the Table. Biomarker analyses, including efficacy by PD-L1 status, will be presented. Conclusions: In this largest data set to date evaluating an ADC combined with an anti-PD-1/L1 agent in the 1L setting, the combination of Dato-DXd plus pembro treatment both with and without Pt-CT elicited durable antitumor activity in pts with aNSCLC. Tolerability of the combinations was as expected, based on known profiles of the individual agents. Clinical trial information: NCT04526691 . All 1L (n=96) 1L, Nonsquamous (n=75) 1L, Squamous (n=21) Response, n (%) Doublet (n=42) Triplet (n=54) Doublet (n=33) Triplet (n=42) Doublet (n=9) Triplet (n=12) Confirmed objective response rate 23 (55) 30 (56) 17 (52) 24 (57) 6 (67) 6 (50) Complete response 1 (2) 2 (4) 1 (3) 2 (5) 0 0 Partial response 22 (52) 28 (52) 16 (49) 22 (52) 6 (67) 6 (50) Stable disease 14 (33) 18 (33) 12 (36) 14 (33) 2 (22) 4 (33) Progressive disease 3 (7) 2 (4) 3 (9) 1 (2) 0 1 (8) Disease control rate a 37 (88) 48 (89) 29 (88) 38 (91) 8 (89) 10 (83) Median duration of response, mo (95% CI) 20.1 (9.7–NE) 13.7 (5.7–NE) 24.9 (9.7–NE) 18.0 (8.0–NE) 12.0 (5.5–NE) 5.5 (4.1–NE) Median PFS, mo (95% CI) 11.2 b (8.2–21.3) 6.8 c (5.5–11.1) 11.2 (6.1–21.3) 10.8 (5.5–17.3) 10.2 (0.4–NE) 6.7 (1.0–8.2) a Proportion of pts with confirmed CR + PR + SD at 12 wks. b.c Median (95% CI) PFS follow-up, mo: b 17.3 (11.3−26.8); c 23.5 (17.3−27.9). mo, months; NE, not evaluable.

3116 Background: Pralsetinib is an oral tyrosine kinase inhibitor that selectively and potently targets oncogenic RET fusion and mutation proteins. RET fusions or mutations are present in various tumor types. We report the final results from the phase 2 portion of ARROW, a phase 1/2, open-label, multi-cohort, dose-expansion study evaluating the efficacy and safety of pralsetinib (NCT03037385) in patients with RET fusion-positive solid tumors other than non-small-cell lung cancer (NSCLC) and thyroid cancer. Methods: Eligible pts were ≥18 years of age with a pathologically documented, definitively diagnosed advanced solid tumor with an oncogenic RET fusion or mutation, had previously received standard of care appropriate for their tumor type, and were not eligible for any other study groups. Overall response rate (ORR) and safety were primary endpoints of the study. Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). The final database lock was May 20, 2024. Results: Twenty-nine patients were enrolled with 11 different solid tumor histologies. Twenty-six (90%) received prior systemic therapy. Median age was 58 years (range 25-75); 59% were female. Twenty-eight patients were included in the efficacy analysis. ORR (by RECIST) was 46.4% (13/28); 10.7% (3/28) achieved complete response (pancreatic cancer, n=2; cancer of unknown primary, n=1) and 35.7% (10/28) achieved partial response. Median PFS was 7 months (95% CI: 3.9, 12.8). Median DOR was 11.1 months (95% CI: 5.5, 25.1). Median OS was 10.3 months (95% CI: 6.8, 25.2). Twenty-five (86%) patients experienced treatment-related adverse events (TRAEs); 19/29 (66%) reported TRAEs ≥grade 3. The most common TRAEs included increased aspartate aminotransferase (11/29; 38%), increased alanine aminotransferase (10/29; 35%), and anemia (9/29; 31%). Four (13.8%) patients experienced hypertension, and 1 (3.4%) patient had ≥grade 3 hypertension. No new safety risks were identified; AEs remained manageable with supportive care and/or dose modifications. Conclusions: In the phase 2 portion of this trial, responses were observed in many tumor types (Table). Pralsetinib demonstrated robust and durable anti-tumor activity with an ORR of 46.4%. These data validate RET fusions as a tissue-agnostic target with sensitivity to RET inhibition and activity beyond NSCLC and thyroid cancer, further supporting the promising potential of pralsetinib to address the unmet medical need in these patients. Clinical trial information: NCT03037385 . Overall response rate by tumor type. Cancer Type (patient n) ORRn (%) Pancreatic (5) 5 (100) Cancer of unknown primary (1) 1 (100) Neuroendocrine (3) 2 (67) Sarcoma (3) 2 (67) Head and neck (2) 1 (50) Small cell lung (2) 1 (50) Hepatobiliary (4) 1 (25) Colorectal (5), gastric (1), ovarian (1), thymic (1) 0

8617 Background: Dato-DXd is an antibody-drug conjugate (ADC) composed of an anti-TROP2 monoclonal antibody linked to a potent topoisomerase I inhibitor payload. We report updated findings from TROPION-Lung02 (NCT04526691) evaluating Dato-DXd plus pembro with or without Pt-CT as 1L therapy for aNSCLC. Methods: Patients (Pts) received Dato-DXd (4 or 6 mg/kg) plus pembro 200 mg alone (doublet) or with Pt-CT (triplet; cisplatin 75 mg/m2 or carboplatin AUC 5) Q3W across 6 cohorts. Pts in the expansion stage were primarily treatment (tx)-naïve. PD-L1 expression was evaluated by tumor proportion score (TPS < 50% or ≥50%) using immunohistochemistry (22C3 assay). The primary objectives were safety and tolerability, with efficacy a secondary objective. Results: 96 pts were treated with doublet (n = 42) or triplet (n = 54) therapy in the 1L setting. At data cutoff (Oct 31, 2023), 45% and 20% of pts receiving doublet or triplet tx were ongoing. Median age was 66 years in both subgroups. Median treatment durations were 6.6 and 5.8 months. Across doublet and triplet tx, the most common any-grade (Gr) treatment-emergent adverse events (TEAEs) were stomatitis (57%, 33%) and nausea (40%, 46%), mainly Gr 1–2. Gr ≥3 TEAEs were seen in 57% and 76% of pts; serious TEAEs in 38% and 44%. TEAEs associated with Dato-DXd discontinuation occurred in 29% and 39% of pts receiving doublet or triplet tx. TEAEs associated with death were seen in 2% and 9%, none considered related to study drug. Efficacy outcomes, including ORR and preliminary PFS, in the 1L setting overall and by PD-L1 status are summarized in the Table. Conclusions: As 1L therapy for aNSCLC, Dato-DXd plus pembro with or without Pt-CT continues to demonstrate durable antitumor activity. Efficacy was observed regardless of PD-L1 expression. Tolerability of the combinations was as expected based on known profiles of the individual agents, with no new safety signals observed. To date, this is the largest dataset reported for any ADC combined with an anti-PD-1/L1 agent in the 1L setting for aNSCLC. Clinical trial information: NCT04526691 . [Table: see text]

9004 Background: Despite advances in first-line (1L) immunotherapy ± CT, most patients (pts) with aNSCLC experience disease progression, necessitating novel strategies. Dato-DXd is an antibody drug conjugate (ADC) composed of a humanized anti-TROP2 IgG1 monoclonal antibody covalently linked to a topoisomerase I inhibitor payload via a plasma-stable tetrapeptide-based cleavable linker. Dato-DXd had encouraging efficacy and manageable safety in heavily pretreated aNSCLC. Dato-DXd + immunotherapy yielded greater preclinical activity than either agent alone. Methods: TROPION-Lung02 (NCT04526691) is a phase 1b, global, dose-escalation and -expansion study evaluating Dato-DXd (4 or 6 mg/kg) + pembro 200 mg ± Pt-CT (cisplatin 75 mg/m2 or carboplatin AUC 5) every 21 days across 6 cohorts. Pts in escalation may have received ≤2 prior lines of therapy for aNSCLC. Pts in expansion were primarily treatment (tx) naive (pts receiving Dato-DXd + pembro may have ≤1 prior Pt-based tx). The primary objective is to assess safety and tolerability, including dose-limiting toxicities (DLTs). Secondary objectives include evaluation of efficacy, pharmacokinetics, and immunogenicity. Results: As of the Oct 31, 2022, data cutoff (DCO), 120 pts were treated. All cohorts met DLT criteria to move to escalation. Median age was 65 years. PD-L1 expression was <1%, 1%-49%, and ≥50% in 40%, 33%, and 26% of pts, respectively. Median tx duration was 4.6 mo, with 55% receiving tx at DCO. The most frequent any-grade (gr) tx-emergent adverse events (TEAEs) were nausea (45%) and stomatitis (45%). Gr ≥3 TEAEs occurred in 61% of pts; most frequent were neutrophil count decreased (8%) and amylase increased (8%). TEAEs that were serious, associated with discontinuation, or associated with death occurred in 31%, 24% (16% associated with Dato-DXd), and 6% of pts, respectively. Dose reductions due to TEAEs associated with Dato-DXd occurred in 17%. Drug-related interstitial lung disease occurred in 12 pts (10%; 9 gr 1/2; 3 gr 3). The objective response rate (ORR) with 1L Dato-DXd + pembro doublet and Dato-DXd + pembro + Pt-CT triplet tx was 60% (95% CI, 36%-81%; 12 [2 unconfirmed]/20) and 55% (95% CI, 39%-70%; 23 [5 unconfirmed]/42), respectively. The ORR for any line of therapy was 38% (95% CI, 25%-54%; 18 [2 unconfirmed]/47) with doublet and 47% (95% CI, 34%-60%; 28 [5 unconfirmed]/60) with triplet tx. In both subsets, the disease control rate was 85% and median duration of response was not reached. Responses were observed in all 3 PD-L1 expression level subgroups. Although immature, median progression-free survival (95% CI) was 10.8 (8.3-15.2) and 7.8 mo (5.5-NE) with doublet and triplet tx, respectively. Conclusions: Dato-DXd + pembro ± Pt-CT demonstrated tolerable safety with notable 1L activity in this first and largest dataset with an ADC + immunotherapy ± Pt-CT in aNSCLC pts. Clinical trial information: NCT04526691 .

9089 Background: RET fusions are targetable oncogenic drivers in 1–2% of non-small cell lung cancer (NSCLC). ARROW (NCT03037385) supported the US FDA approval of pralsetinib, a highly potent oral selective RET inhibitor for RET-altered NSCLC and thyroid cancer. Here, we present updated results for a larger population of patients with RET fusion–positive NSCLC enrolled in ARROW. Methods: ARROW is a phase 1/2 open-label study conducted at 84 sites in 13 countries. Phase 2 expansion cohorts included patients with RET fusion–positive NSCLC. Initially, all treatment-naïve patients were not candidates for platinum-based therapy, a requirement removed by protocol amendment in July 2019. Primary objectives are overall response rate (ORR; blinded independent central review [BICR] per RECIST v1.1), assessed for patients with baseline measurable disease, and safety. Results: Updated analyses were completed as of Nov 6, 2020 (data cut-off), for patients who initiated pralsetinib 400 mg QD by May 22, 2020 (enrollment cut-off). Efficacy results, including analyses for treatment-naïve patients enrolled after eligibility criteria were revised to allow candidates for platinum-based therapy, are shown in the Table. Conclusions: Pralsetinib showed rapid, potent, and durable clinical activity in patients with RET fusion-positive NSCLC (regardless of prior therapies), including poor prognosis patients not eligible for platinum-based therapy. Overall, pralsetinib was well-tolerated. These data highlight the need for RET testing early in the course of disease to identify candidates who may benefit from treatment with pralsetinib. Clinical trial information: NCT03037385. [Table: see text]

3079 Background: RET fusions are targetable oncogenic drivers in multiple solid tumor types. ARROW study (NCT03037385) data supported the US FDA approval of pralsetinib, a once-daily (QD) oral highly potent and selective RET inhibitor, for RET-altered metastatic non-small cell lung cancer (NSCLC) and advanced/metastatic thyroid cancer. Here we provide an update on the clinical activity of pralsetinib in patients (pts) with advanced RET fusion-positive solid tumors other than NSCLC and thyroid cancer (“other” RET fusion–positive solid tumors). Methods: The global ongoing ARROW study (84 sites in 13 countries) includes phase 1 dose-escalation (30–600 mg [QD or twice daily]) and phase 2 expansion cohorts (400 mg QD) defined by tumor type and RET alteration status. Primary objectives are overall response rate (ORR; blinded independent central review per RECIST v1.1) and safety. Results: Updated analyses were completed as of Nov 6, 2020 (data cut-off) for 21 pts with other RET fusion–positive solid tumors enrolled by May 22, 2020 (enrollment cut-off) (lung other than NSCLC, n = 4; pancreatic, n = 3; colon, n = 3; cholangiocarcinoma, n = 3; unknown primary [UP], n = 2; other, n = 6). Overall, 11 (52%) pts received ≥2 prior lines of therapy for metastatic disease. The most common RET fusion partners were CCDC6 and KIF5B (24% each), NCOA4 (19%), other (10%), and unknown (24%). Two pts with colon cancer were excluded from efficacy analyses due to other driver mutations ( KRAS, PIK3CB). In 19 evaluable pts, ORR was 53% (95% CI, 29–76) with 2 (11%) complete responses (CR) and 8 (42%) partial responses (PR). Responses occurred across multiple tumor types including 3/3 pts with pancreatic cancer (including a CR ongoing at 20.8 months on treatment), 2/2 pts with UP, 2/3 pts with cholangiocarcinoma, and in pts with mesenchymal, salivary duct, and lung carcinoid tumors. Median duration of response was 19.0 months (95% CI, 5.5–not estimable). Clinical benefit rate (proportion with CR, PR, or stable disease persisting ≥16 weeks) was 68% (95% CI, 43–87). Tumor shrinkage was observed in 89% of 18 evaluable pts with post-baseline tumor assessment. In all pts enrolled in ARROW who received pralsetinib 400 mg QD irrespective of tumor type (n = 471) the most common (≥25%) treatment-related adverse events (TRAEs) were increased aspartate aminotransferase (39%), anemia (35%), increased alanine aminotransferase (28%), constipation (26%), and hypertension (25%). Overall, 6% of pts discontinued treatment due to TRAEs. Conclusions: Pralsetinib showed robust, durable antitumor activity in patients with multiple RET fusion‒positive, heavily pre-treated, advanced solid tumors, and was well tolerated. These data highlight the need for broad RET testing to identify candidates who could benefit from treatment with pralsetinib. Enrollment of patients with other RET fusion–positive solid tumors in ARROW is ongoing. Clinical trial information: NCT03037385.

8072 Background: Figitumumab (CP-751,871) is a fully human, IgG2monoclonal antibody against the insulin-like growth factor type I receptor (IGF-IR). We reported in a randomized phase II study (ASCO 2008), preliminary evidence of high activity of the combination of paclitaxel (T), carboplatin (C) and figitumumab (F) in advanced treatment-naïve NSCLC of squamous cell histology (n=11 pts). A single arm trial extension cohort was conducted to confirm those findings. Methods: Fifty-six pts with non-adenocarcinoma NSCLC were enrolled. Pts received T (200 mg/m2), C (AUC of 6) and F (20 mg/kg) q3weeks for up to 6 cycles; pts with response (PR) or stable disease were eligible to continue F as single agent until disease progression. Statistical hypotheses were 30% (null) versus 50% (response of interest). Protein expression of the IGF-IR in core tumor biopsies was quantified using automated quantitative analysis (AQUA) technology. Results: Pts were 72% male, 28% >70 years old and 91% stage IV. Median number of treatment cycles was 4, with 46% of pts receiving single agent F beyond cycle 4. TCF was well tolerated. The most common all-causality grade 3, 4 CTCAE adverse events were neutropenia (21%), hyperglycemia (14%) and fatigue (14%). Hyperglycemia adverse events almost always occurred within the first treatment cycle and were manageable with standard measures. Responses in squamous pts are currently 25 out of 40 pts according to RECIST, with final response assessment still pending for 7 additional pts (≥53%, p<0.001). One complete response and 7 striking PRs (50–80% tumor size reduction at cycle 2) were observed. Tumor size reductions with F maintenance treatment were also seen in 2 pts. Median progression free survival has not been yet reached at 4 months follow up. A trend (p=0.1) for higher IGF-IR expression in patients responding to TCF was observed in a small data set (n=12). Median tumor IGF-IR expression in pts responding to TCF therapy and non-responders were respectively 6287 and 4131 AQUA scores. Analysis of IGF-IR and other members of the IGF-IR pathway continues. Conclusions: These data further support the activity of figitumumab combination therapy in pts with squamous NSCLC. [Table: see text]

8522 Background: CC-223 is an ATP-competitive inhibitor of the mTOR kinase, including both TORC1 and TORC2 complexes. CC-223 was selected to address resistance of rapamycin analogues mediated by TORC2 activation. Methods: Following establishment of the MTD (reported at ASCO 2012), subjects with advanced DLBCL, MM and select solid tumors were enrolled in parallel expansion cohorts of up to 20 evaluable subjects. CC-223 was dosed at 45 mg once daily in 28 day cycles until disease progression. Results: As of 09 January, 2013, 35 subjects were enrolled including DLBCL (21) and MM (14). Results in solid tumor cohorts are reported separately. The most common (> 20%) related adverse events (all grades) were fatigue, hyperglycemia, rash, anorexia, nausea, vomiting and diarrhea. In addition, related serious adverse events included infection (2), pneumonitis (1), renal insufficiency (2), pancreatitis (1) and thrombocytopenia (1). CC-223 dose reduction was required in 9 subjects (27%), usually during cycle 1 or 2, and 4 additional subjects with DLBCL dropped out during cycle 1 due to toxicity. Systemic exposure was similar between the two tumor cohorts and was associated with inhibition of TORC1 (p4EBP1) and TORC2 (pAKT) biomarkers in blood cells. Reduction in glucose uptake (32 – 98% decrease) on PET imaging at day 15 was observed in 7/7 DLBCL subjects with results currently available. Three of 17 evaluable subjects with DLBCL had partial responses (PR) after 2 cycles; two with rapid and near complete regression (> 90%) of target lesions by CT and PET with PR confirmed and treatment ongoing at 6 and 8 cycles. Both had failed multiple prior treatment regimens (5 and 3, respectively), including autologous stem cell transplant (ASCT). No responses were observed in 10/14 evaluable subjects with MM although 2 subjects have prolonged stable disease (SD) with treatment ongoing at 12 and 14 cycles. Conclusions: Encouraging signals of biomarker and clinical activity were observed in DLBCL, including two near complete responses, which are ongoing. Due to dose reductions and interruptions, a starting dose of 30 mg QD is recommended for future studies. Clinical trial information: NCT01177397.