New active drugs for the treatment of advanced colorectal cancer

Oxaliplatin retreatment in metastatic colorectal cancer: Systematic review and future research opportunities

BACKGROUND

Oxaliplatin represents a main component of cytotoxic treatment regimens in colorectal cancer (CRC). Given its efficacy, oxaliplatin is frequently re-administered in the context of the continuum of care in metastatic CRC (mCRC). However, efficacy and tolerability of this therapeutic strategy has not been comprehensively assessed.

METHODS

We performed a systematic review of the literature on September 19th 2020, according to PRISMA criteria 2009. The research was performed on PubMed, ASCO Meeting Library, ESMO library and ClinicalTrials.gov for citations or ongoing trials.

RESULTS

64 records were retrieved and 13 included in the systematic review: 8 full-text articles, 4 abstracts and 1 ongoing clinical trial. According to readministration timing, studies were classified as rechallenge/reintroduction (n = 8) or stop & go/intermittent therapeutic strategies (n = 4). The studies presented wide heterogeneity in terms of efficacy (Response Rate 6-31%; Disease Control Rate 39-79%; median Progression-Free Survival 3.1-7 months). Those patients who received retreatment after prior adjuvant oxaliplatin or exploiting a stop-&-go strategy appeared to achieve better outcomes. However, no formal comparisons on treatment outcomes were feasible. The most frequent grade 3 or higher adverse events were hematologic toxicities (5-27%), peripheral neuropathy (5-14%) and hypersensitivity reactions (5-20%).

CONCLUSIONS

Retreatment with oxaliplatin for mCRC is practiced based on scarce and heterogeneous data indicating efficacy and manageable toxicity. The best strategy to exploit this approach remains to be defined, and the most promising research avenue to improve therapeutic index of oxaliplatin is represented by selection of responder patients whose tumors harbor molecular defects in the DNA damage repair pathway.

Neutropenia is an indicator of outcomes in metastatic colorectal cancer patients treated with FTD/TPI plus bevacizumab: a retrospective study

PURPOSE

Trifluridine/tipiracil (FTD/TPI) improves the overall survival (OS) of metastatic colorectal cancer (mCRC) patients. Additionally, FTD/TPI plus bevacizumab (BEV) has demonstrated promising efficacy for mCRC patients who are refractory to standard chemotherapy. Chemotherapy-induced neutropenia (CIN) has been reported to be an indicator of efficacy for FTD/TPI. This study investigated whether CIN was an indicator of efficacy for FTD/TPI plus BEV.

METHODS

We reviewed chemo-refractory mCRC patients who were treated with FTD/TPI alone (monotherapy) or FTD/TPI plus BEV (combination) at our institution and compared the safety and efficacy of the two. Progression-free survival (PFS) and OS were analyzed using Kaplan-Meier curves. We also investigated correlations between CIN and outcomes.

RESULTS

In total, 56 patients received FTD/TPI, among whom 24 and 32 were treated with monotherapy and combination therapy, respectively. The median PFS was 1.8 and 4.7 months for the monotherapy and combination arms, respectively (hazard ratio [HR]: 0.28; 95% confidence interval [CI]: 0.15-0.51; P < 0.001). The median OS was 6.3 and 11.7 months for the monotherapy and combination arms, respectively (HR 0.25; 95% CI 0.13-0.48; P < 0.001). CIN (Grade 3 or worse) developed in five (20.8%) and 17 (53.1%) patients from the monotherapy and combination arms, respectively (P = 0.030). Patients with CIN in the combination arm had improved PFS and OS compared with non-CIN patients (P = 0.033 and P = 0.045, respectively).

CONCLUSIONS

FTD/TPI plus BEV prolonged PFS and OS and had tolerable toxicity compared with FTD/TPI alone. CIN is an indicator of patients who will benefit from FTD/TPI plus BEV.

Treatment Patterns and Outcomes in Patients with KRAS Wild-Type Metastatic Colorectal Cancer Treated in First Line with Bevacizumab- or Cetuximab-Containing Regimens

PURPOSE

Patients with Kirsten rat sarcoma viral oncogene wild-type (KRAS WT) metastatic colorectal cancer (mCRC) treated in first line with bevacizumab (B) or cetuximab (C) plus standard chemo backbones had comparable outcomes in phase III Cancer and Leukemia Group B (CALGB) 80405. We examined comparative effectiveness of B and C regimens in real-world community settings.

METHODS

This retrospective study examined progression-free survival (PFS) and OS in a US community sample of KRAS WT mCRC patients treated with first-line B (n = 254) or C (n = 146) regimens. Medical records from the Vector Oncology Data Warehouse were used. Disease progression was determined from patient charts. OS was measured from the start of first-line treatment until death.

RESULTS

There were no significant difference in either PFS or OS respectively between B-treated compared to C-treated patients (HR = 1.324, 95% CI 0.901, 1.947; HR = 1.080, 95% CI 0.721, 1.617). More B patients received oxaliplatin backbones (74.8 vs. 36.3%), and more C patients received irinotecan backbones (51.4 vs. 20.1%), ps < 0.001. Multivariate survival analyses showed a significant difference indicating a greater risk for death among C-treated patients with right-sided tumors vs. left-sided tumors (HR = 2.263, 95% CI 1.394, 3.673, p = 0.0009), but not for B-treated patients (HR = 1.209, 95% CI 0.825, 1.771, p = 0.3297).

CONCLUSIONS

Consistent with CALGB 80405, median PFS and OS for these community oncology KRAS WT mCRC patients treated with first-line B or C regimens did not differ significantly.

Results of a Randomized, Double-Blind, Placebo-Controlled, Phase III Trial of Trifluridine/Tipiracil (TAS-102) Monotherapy in Asian Patients With Previously Treated Metastatic Colorectal Cancer: The TERRA Study

Purpose

Trifluridine/tipiracil (TAS-102) was effective in patients with metastatic colorectal cancer (mCRC) in a phase II Japanese trial. This regional trial evaluated the efficacy and safety of trifluridine/tipiracil in Asian patients with mCRC with or without exposure to biologic therapy.

Patients and Methods

This randomized, double-blind, placebo-controlled, phase III trial was conducted at 30 sites in China, the Republic of Korea, and Thailand. Patients ≥ 18 years old with histologically or cytologically confirmed adenocarcinoma of the colon or rectum and known KRAS status who were refractory or intolerant to two or more prior chemotherapy regimens were enrolled. Eligible patients were randomly assigned (2:1 ratio; minimization method) to receive trifluridine/tipiracil (twice per day orally; 5 days on and 2 days off for 2 weeks, followed by 14 days off per cycle) or placebo. The primary end point was overall survival (intent-to-treat population).

Results

Between October 16, 2013, and June 15, 2015, 406 patients were randomly assigned to receive trifluridine/tipiracil (n = 271) or placebo (n = 135). Risk of death was significantly lower in the trifluridine/tipiracil arm than in the placebo arm (hazard ratio for death, 0.79; 95% CI, 0.62 to 0.99; log-rank P = .035). Median overall survival was significantly longer in the trifluridine/tipiracil than in the placebo arm (7.8 months [95% CI, 7.1 to 8.8 months] v 7.1 months [95% CI, 5.9 to 8.2 months], respectively), for a median survival follow-up time of 13.8 months (95% CI, 13.1 to 15.3 months) compared with 13.4 months (95% CI, 11.6 to 17.3 months), respectively. The incidence of serious adverse events was similar between the arms (trifluridine/tipiracil, n = 63 [23.2%]; placebo, n = 32 [23.7%]). No treatment-related deaths were reported.

Conclusion

Trifluridine/tipiracil has a statistically significant survival benefit compared with placebo in Asian patients with mCRC refractory or intolerant to standard chemotherapies, regardless of exposure to biologic therapy. The safety profile is similar to previous reports.

Progression-Free Survival in Patients Receiving Chemotherapy Alone (C) or Chemotherapy with Bevacizumab (CB) for First-Line Treatment of KRAS Mutant Metastatic Colorectal Cancer in Community Oncology Settings

PURPOSE

Bevacizumab is a standard first-line (L1) treatment for metastatic colorectal cancer (mCRC) patients regardless of RAS status. This retrospective study examined treatment patterns and outcomes in a community oncology sample of KRAS mutant mCRC patients treated with chemotherapy (C) or C plus bevacizumab (CB) in L1.

METHODS

This study used medical records from the Vector Oncology Data Warehouse. Eligible patients were confirmed KRAS mutant mCRC and received L1 C or CB. Kaplan-Meier analysis assessed L1 progression-free survival (PFS) and overall survival (OS). Cox regression models examined the interaction of tumor location (R/L) with treatment.

RESULTS

CB (n = 264) compared to C (n = 109) patients were younger, less likely performance status (PS) impaired, and more likely with liver metastases. Median unadjusted PFS was 10.41 months (95% CI 9.0-11.3) in CB and 7.66 months (95% CI 6.5-9.1) in C patients (p = 0.174). Median unadjusted OS was 26.91 months (95% CI 24.3-29.3) in CB and 23.33 months (95% CI 19.7-29.2) in C patients (p = 0.571). For patients with right- vs. left-sided tumors, C (but not CB)-treated patients had higher adjusted risk for progression (HR = 1.715, 95% CI 1.108, 2.653; p = 0.015).

CONCLUSIONS

CB- vs. C-treated KRAS mutant mCRC patients may have a meaningful PFS benefit. Patients with right-sided tumors treated with C were at higher risk for disease progression than patients with left-sided tumors. Tumor location had no significant effect on outcomes in the CB cohort.

EMICORON: A multi-targeting G4 ligand with a promising preclinical profile

BACKGROUND

During the last decade, guanine G-rich sequences folding into G-quadruplex (G4) structures have received a lot of attention and their biological role is now a matter of large debate. Rising amounts of experimental evidence have validated several G-rich motifs as molecular targets in cancer treatment. Despite that an increasing number of small molecules has been reported to possess excellent G4 stabilizing properties, none of them has progressed through the drug-development pipeline due to their poor drug-like properties. In this context, the identification of G4 ligands with more favorable pharmacological properties and with a well-defined target activity could be fruitful for anticancer therapy application.

SCOPE OF REVIEW

This manuscript outlines the current state of knowledge regarding EMICORON, a G4-interactive molecule structurally and biologically similar, on the one side, to coronene and, on the other side, to a bay-monosubstituted perylene.

MAJOR CONCLUSIONS

Overall this work evidences that EMICORON, a new promising G4 ligand, possesses a marked antitumoral activity both standing alone and in combination with chemotherapeutics. Moreover, EMICORON represents a good example of multimodal class of antitumoral drug, able to simultaneously affect multiple targets participating in several distinct signaling pathways, thus simplifying the treatment modalities and improving the selectivity against cancer cells.

GENERAL SIGNIFICANCE

Due to the importance of G4 forming sequences in crucial biological processes participating in tumor progression, their successful targeting with small molecules could represent a very important innovation in the development of effective therapeutic strategies against cancer. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.

Targeting angiogenesis in gastrointestinal tumors: current challenges

Colorectal cancer (CRC) is one of the few cancers where screening modalities are standardized, but it still remains the third leading cause of cancer related mortality. For more than a decade now, the approval of anti-angiogenic therapy has led to an increase in the rate of overall survival (OS) of patients with advanced colon cancer. The drawback of the anti-angiogenic therapy is that their effect is short-lived and many patients progress through these therapies. Various mechanisms of resistance have been hypothesized, but overcoming this has been challenging. Also, there are no standardized predictive biomarkers that could aid in selecting patients who responds to the therapy upfront. This review focuses on the basis of angiogenesis, describing the approved anti-angiogenic therapies, discusses the challenges in terms of resistance to anti-angiogenic therapy and also the role of biomarkers. In the future, hopefully newer targeted therapies, immunotherapy, combination therapies and the standardization of biomarkers may result in improved outcomes and cure rates.