RAS and Other Molecular Targets in Pancreatic Cancer: The Next Wave Is Coming.

OPINION STATEMENT: Since the discovery of oncogenes in the 1970s, cancer doctors and researchers alike have understood the promise of discovering drugs to block the dominantly acting function of mutated signaling proteins in cancer. This promise was delivered, first slowly, with early signals inhibiting HER2 and BCR-Abl in the 1990s and 2000s, and then quickly, with kinase inhibitors being approved hand over fist in non-small cell lung cancer, melanoma, and many other malignancies. The RAS proteins, however, remained recalcitrant to chemical inhibition for decades, despite being, by far, the most frequently mutated oncogenes in cancers of all types. Nowhere was this deficit more palpable than in pancreatic ductal adenocarcinoma (PDA), where > 90% of cases are driven by single nucleotide substitutions at a single codon of the KRAS gene. The ice began to crack in 2012 when Ostrem and colleagues (Nature 503(7477): 548-551, 2013) synthesized the first KRAS G12C inhibitors, which covalently bind to GDP-bound G12C-mutated KRAS and lock the oncoprotein in its inactive state. In the last decade, the scientific community has established a new foundation on this and other druggable pockets in mutant KRAS. Here we provide an up-to-date overview of drugs targeting KRAS and other molecular targets in pancreatic cancer.

Lessons learned: the first consecutive 1000 patients of the CCCMunichLMU Molecular Tumor Board.

PURPOSE: In 2016, the University of Munich Molecular Tumor Board (MTB) was implemented to initiate a precision oncology program. This review of cases was conducted to assess clinical implications and functionality of the program, to identify current limitations and to inform future directions of these efforts. METHODS: Charts, molecular profiles, and tumor board decisions of the first 1000 consecutive cases (01/2016-03/2020) were reviewed. Descriptive statistics were applied to describe relevant findings. RESULTS: Of the first 1000 patients presented to the MTB; 914 patients received comprehensive genomic profiling. Median age of patients was 56 years and 58% were female. The most prevalent diagnoses were breast (16%) and colorectal cancer (10%). Different types of targeted or genome-wide sequencing assays were used; most of them offered by the local department of pathology. Testing was technically successful in 88%. In 41% of cases, a genomic alteration triggered a therapeutic recommendation. The fraction of patients receiving a tumor board recommendation differed significantly between malignancies ranging from over 50% in breast or biliary tract to less than 30% in pancreatic cancers. Based on a retrospective chart review, 17% of patients with an MTB recommendation received appropriate treatment. CONCLUSION: Based on these retrospective analyses, patients with certain malignancies (breast and biliary tract cancer) tend to be more likely to have actionable variants. The low rate of therapeutic implementation (17% of patients receiving a tumor board recommendation) underscores the importance of meticulous follow-up for these patients and ensuring broad access to innovative therapies for patients receiving molecular tumor profiling.

FOLFIRI plus cetuximab or bevacizumab for advanced colorectal cancer: final survival and per-protocol analysis of FIRE-3, a randomised clinical trial.

BACKGROUND: Cetuximab plus FOLFIRI improved overall survival compared with bevacizumab plus FOLFIRI in KRAS wild-type metastatic colorectal cancer (mCRC) in FIRE-3, but no corresponding benefit was found for progression-free survival. This analysis aimed to determine whether cetuximab improves response and survival versus bevacizumab among response-evaluable patients receiving first-line FOLFIRI for RAS wild-type mCRC and the effect of primary tumour side on outcomes. METHODS: The intent-to-treat population included 593 patients with KRAS exon 2 wild-type mCRC. Further testing identified 400 patients with extended RAS wild-type disease; of these, 352 (88%) who received ≥3 cycles of therapy and had ≥1 post-baseline scan were evaluable for response and constituted the per-protocol population (169 cetuximab and 183 bevacizumab). Patients received 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) with either weekly cetuximab or biweekly bevacizumab given on day 1 of each 14-day cycle until response, progression or toxicity occurred. The primary endpoint was the objective response rate (ORR) in the per-protocol population. Secondary endpoints included overall survival (OS) and progression-free survival (PFS). The effect of primary tumour location was evaluated. RESULTS: Median OS in the RAS wild-type population was 31 vs 26 months in the cetuximab and bevacizumab groups, respectively (HR 0.76, P = 0.012). In the per-protocol population, outcomes favoured cetuximab for ORR (77% vs 65%, P = 0.014) and median OS (33 vs 26 months, HR 0.75, P = 0.011), while PFS was comparable between groups. The advantage of cetuximab over bevacizumab occurred only in patients with left-sided primary tumours. CONCLUSIONS: FOLFIRI plus cetuximab resulted in a significantly higher ORR and longer OS compared to FOLFIRI plus bevacizumab among patients with left-sided tumours. The superior response associated with cetuximab may particularly benefit patients with symptomatic tumours or borderline-resectable metastases. CLINICALTRIALS. GOV IDENTIFIER: NCT00433927.

Current treatment options in RAS mutant metastatic colorectal cancer patients: a meta-analysis of 14 randomized phase III trials.

PURPOSE: Although biomarkers for patients with metastatic colorectal cancer exist, the benefit patients with RAS mutated tumors derive from established regimens is unclear. METHODS: Efficacy of therapeutic strategies available for RAS mutated patients (addition of chemotherapeutic agents and/or anti angiogenic agents) were investigated in fourteen randomized controlled phase III trials at trial level by meta-analysing individual study hazard ratios and 95% confidence intervals (95% CI) for overall survival (OS) and progression free survival (PFS). RESULTS: 6810 of 10,748 patients (63.3%) were available (48.5% RAS wildtype, 51.5% RAS mutated). Across all treatment lines, additional treatment efficacy (chemotherapy and/or anti angiogenic agents) was significantly smaller in RAS mutated compared to wildtype tumors for OS and PFS. In detail, patients with RAS mutated metastatic colorectal cancer derived significant benefit in PFS but not in OS by the addition of either chemotherapy or anti angiogenic agents to the respective comparator. In patients with RAS wildtype metastatic colorectal cancer, PFS and OS were improved by the addition of chemotherapy or anti angiogenic agent. CONCLUSION: The therapeutic benefit of additional substances is less distinct in patients with RAS mutated as compared to RAS wildtype metastatic colorectal cancer, especially with regard to OS.

Relevance of liver-limited disease in metastatic colorectal cancer: Subgroup findings of the FIRE-3/AIO KRK0306 trial.

In metastatic colorectal cancer (mCRC), liver-limited disease (LLD) is associated with a higher chance of metastectomy leading to long-term survival. However, limited data describes the prognostic and predictive relevance of initially unresectable LLD with regard to targeted first-line therapy. The present analysis investigated the relevance of initially unresectable LLD in mCRC patients treated with targeted therapy against either the epidermal growth factor receptor (EGFR) or vascular epithelial growth factor (VEGF). The analysis was performed based on FIRE-3, a randomized phase III trial comparing first-line chemotherapy with FOLFIRI plus either cetuximab (anti-EGFR) or bevacizumab (anti-VEGF) in RAS wild-type (WT) mCRC. Of 400 patients, 133 (33.3%) had LLD and 267 (66.8%) had non-LLD. Median overall survival (OS) was significantly longer in LLD compared to non-LLD patients (36.0 vs. 25.4 months; hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.51-0.87; p = 0.002). In a multivariate analysis also including secondary hepatic resection as time-dependent variable, LLD status was independently prognostic for OS (HR = 0.67; 95% CI: 0.50-0.91; p = 0.01). As assessed by interaction tests, treatment benefit from FOLFIRI plus cetuximab compared to FOLFIRI plus bevacizumab was independent of LLD status with regard to objective response rate (ORR), early tumour shrinkage ≥20% (ETS), depth of response (DpR) and OS (all p > 0.05). In conclusion, LLD could be identified as a prognostic factor in RAS-WT mCRC, which was independent of hepatic resection in patients treated with targeted therapy. LLD had no predictive relevance since benefit from FOLFIRI plus cetuximab over bevacizumab was independent of LLD status.