Phase II study of capecitabine-based concomitant chemoradiation followed by durvalumab as a neoadjuvant strategy in locally advanced rectal cancer: the PANDORA trial

BACKGROUND

This study investigated the efficacy of chemoradiotherapy (CRT) followed by durvalumab as neoadjuvant therapy of locally advanced rectal cancer.

PATIENTS AND METHODS

The PANDORA trial is a prospective, phase II, open-label, single-arm, multicenter study aimed at evaluating the efficacy and safety of preoperative treatment with durvalumab (1500 mg every 4 weeks for three administrations) following long-course radiotherapy (RT) plus concomitant capecitabine (5040 cGy RT in 25-28 fractions over 5 weeks and capecitabine administered at 825 mg/m2 twice daily). The primary endpoint was the pathological complete response (pCR) rate; secondary endpoints were the proportion of clinical complete remissions and safety. The sample size was estimated assuming a null pCR proportion of 0.15 and an alternative pCR proportion of 0.30 (α = 0.05, power = 0.80). The proposed treatment could be considered promising if ≥13 pCRs were observed in 55 patients (EudraCT: 2018-004758-39; NCT04083365).

RESULTS

Between November 2019 and August 2021, 60 patients were accrued, of which 55 were assessable for the study's objectives. Two patients experienced disease progression during treatment. Nineteen out of 55 eligible patients achieved a pCR (34.5%, 95% confidence interval 22.2% to 48.6%). Regarding toxicity related to durvalumab, grade 3 adverse events (AEs) occurred in four patients (7.3%) (diarrhea, skin toxicity, transaminase increase, lipase increase, and pancolitis). Grade 4 toxicity was not observed. In 20 patients (36.4%), grade 1-2 AEs related to durvalumab were observed. The most common were endocrine toxicity (hyper/hypothyroidism), dermatologic toxicity (skin rash), and gastrointestinal toxicity (transaminase increase, nausea, diarrhea, constipation).

CONCLUSION

This study met its primary endpoint showing that CRT followed by durvalumab could increase pCR with a safe toxicity profile. This combination is a promising, feasible strategy worthy of further investigation.

In-vivo evaluations of bone regenerative potential of two novel bioactive glasses

Due to the aging of population, materials able to repair damaged tissues are needed. Among others, bioactive glasses (BGs) have attracted a lot of interest due to their outstanding properties both for hard and soft tissues. Here, for the first time, two new BGs, which gave very promising results in preliminary in vitro-tests, were implanted in animals in order to evaluate their regenerative potential. The new BGs, named BGMS10 and Bio_MS and containing specific therapeutic ions, were produced in granules and implanted in rabbits' femurs for up to 60 days, to test their biocompatibility and osteoconduction. Additionally, granules of 45S5 Bioglass® were employed and used as a standard reference for comparison. The results showed that, after 30 days, the two novel BGs and 45S5 displayed a similar behavior, in terms of bone amount, thickness of new bone trabeculae and affinity index. On the contrary, after 60 days, 45S5 granules were mainly surrounded by wide and scattered bone trabeculae, separated by large amounts of soft tissue, while in BGMS10 and Bio_MS the trabeculae were thin and uniformly distributed around the BG granules. This latter scenario could be considered as more advantageous, since the features of the two novel BG granules allowed for the neo-formation of a uniformly distributed bony trabeculae, predictive of more favorable mechanical behavior, compared to the less uniform coarse trabeculae, separated by large areas of soft tissue in 45S5 granules. Thus, BGMS10 and Bio_MS could be considered suitable products for tissue regeneration in the orthopedic and dental fields.

Impact of age and gender on the efficacy and safety of upfront therapy with panitumumab plus FOLFOX followed by panitumumab-based maintenance: a pre-specified subgroup analysis of the Valentino study

BACKGROUND

The safety and efficacy outcome of elderly metastatic colorectal cancer (mCRC) patients fit enough to receive combination chemotherapy plus biological agents is an issue of growing interest. Also, gender-specific differential toxicity and efficacy of anti-epidermal growth factor receptor (EGFR)-based upfront treatments need to be explored.

PATIENTS AND METHODS

Valentino was a multicenter, randomized, phase II trial, investigating two panitumumab-based maintenance strategies following first-line panitumumab plus FOLFOX in RAS wild-type mCRC patients. We carried out a subgroup analysis, aimed at assessing the differences in efficacy, safety and quality of life (QoL) according to age (<70 versus ≥70 years) and gender (male versus female). Efficacy endpoints were progression-free survival (PFS), overall survival (OS) and overall response rate (ORR); safety endpoints were rates of any grade and grade 3/4 adverse events (AEs).

RESULTS

No significant differences in terms of PFS, OS and ORR were observed between patients aged <70 or ≥70 years and the effect of the maintenance treatment arm on survival outcomes was similar in the two subgroups. The safety profile of both induction and maintenance treatment and the impact on QoL were similar in elderly and younger patients. No significant differences in PFS, OS, ORR or clinical benefit rate were observed according to gender. A significantly higher rate of overall grade 3/4 AEs (P = 0.008) and of grade 3/4 thrombocytopenia (P = 0.017), any grade and grade 3/4 neutropenia (P < 0.0001) and any grade conjunctivitis (P = 0.033) was reported in female as compared to male patients. Conversely, we reported a significantly higher incidence of any grade skin rash (P = 0.0007) and hypomagnesemia (P = 0.029) in male patients.

CONCLUSIONS

The upfront choice of an anti-EGFR-based doublet chemotherapy followed by a maintenance strategy represents a valuable option in RAS wild-type mCRC irrespective of gender and age, though a careful evaluation of patients to maximize the risk/benefit ratio is warranted.

Molecular determinants of clinical outcomes with pembrolizumab versus paclitaxel in a randomized, open-label, phase III trial in patients with gastroesophageal adenocarcinoma

BACKGROUND

In the phase III KEYNOTE-061 trial (NCT02370498), pembrolizumab did not significantly improve overall survival versus paclitaxel as second-line therapy for gastric/gastroesophageal junction (GEJ) adenocarcinoma with programmed death-ligand 1 (PD-L1) combined positive score (CPS) ≥1 tumors. The association of tissue tumor mutational burden (tTMB) status and clinical outcomes was determined, including the relationship with CPS and microsatellite instability-high (MSI-H) status.

PATIENTS AND METHODS

In patients with whole exome sequencing (WES) data [420/592 (71%); pembrolizumab, 218; paclitaxel, 202], the association of tTMB with objective response rate (ORR; logistic regression), progression-free survival (PFS; Cox proportional hazards regression), and overall survival (OS; Cox proportional hazards regression) were measured using one-sided (pembrolizumab) and two-sided [paclitaxel] P values. tTMB was also evaluated using FoundationOne®CDx [205/592 (35%)]. Prespecified equivalent cut-offs of 175 mut/exome for WES and 10 mut/Mb for FoundationOne®CDx were used.

RESULTS

WES-tTMB was significantly associated with ORR, PFS, and OS in pembrolizumab-treated (all P < 0.001) but not paclitaxel-treated patients (all P > 0.6) in univariate analysis. The area under the receiver operating characteristics curve for WES-tTMB and response was 0.68 [95% confidence interval (CI) 0.56-0.81] for pembrolizumab and 0.51 (95% CI 0.39-0.63) for paclitaxel in univariate analysis. There was low correlation between WES-tTMB and CPS in both treatment groups (r ≤ 0.16). WES-tTMB remained significantly associated with all clinical endpoints with pembrolizumab after adjusting for CPS and with PFS and OS after excluding known MSI-H tumors (n = 26). FoundationOne®CDx-tTMB demonstrated a positive association with ORR, PFS, and OS in pembrolizumab-treated patients (all P ≤ 0.003) but not PFS or OS in paclitaxel-treated patients (P > 0.1).

CONCLUSION

This exploratory analysis from KEYNOTE-061 is the first to demonstrate a strong association between tTMB and efficacy with pembrolizumab but not paclitaxel in patients with gastric/GEJ adenocarcinoma in a randomized setting. Data further suggest tTMB is a significant and independent predictor beyond PD-L1 status.

Predictive role of microsatellite instability for PD-1 blockade in patients with advanced gastric cancer: a meta-analysis of randomized clinical trials

BACKGROUND

Several post hoc analyses of randomized controlled trials (RCTs) suggested the importance of microsatellite instability (MSI) as a positive predictive factor to immunotherapy in patients with advanced gastric cancer (GC); however, individually these have low statistical power.

METHODS

RCTs investigating treatment with or without an anti-programmed cell death protein 1 (PD-1) agent for advanced GC and providing outcome according to MSI status were selected. The hazard ratio (HR) and the odds ratio were used to compare the treatment effect on survival outcomes and tumor response, respectively, for anti-PD-1-based therapy compared with standard therapy. Evidence for treatment effect by MSI status was evaluated by a test of interaction.

RESULTS

The phase III KEYNOTE-062, CheckMate-649, JAVELIN Gastric 100 and KEYNOTE-061 trials were included. A total of 2545 patients with evaluable MSI status were included and 123 (4.8%) had MSI-high cancers. The HR for overall survival benefit with anti-PD-1-based regimens was 0.34 (95% CI: 0.21-0.54) for MSI-high cancers versus 0.85 [95% confidence interval (CI): 0.71-1.00] for microsatellite stable. The treatment effect was significantly different in the two subgroups (P for interaction 0.003). In the MSI-high subgroup, the HR for progression-free survival was 0.57 (95% CI: 0.33-0.97; P = 0.04) and the odds ratio for response was 1.76 (95% CI: 1.10-2.83; P = 0.02).

CONCLUSIONS

Patients with MSI-high GC should be regarded as a specific and highly immunosensitive population worthy of dedicated clinical trials.

Temozolomide and irinotecan (TEMIRI regimen) as salvage treatment of irinotecan-sensitive advanced colorectal cancer patients bearing MGMT methylation

Background

Non-randomized studies showed that temozolomide (TMZ) achieves an average 10% response rate in heavily pretreated metastatic colorectal cancer (mCRC) patients with promoter methylation of the DNA repair gene O6-methylguanine-DNA methyltransferase (MGMT). In this phase II trial, irinotecan and temozolomide (TEMIRI) combination regimen was assessed in irinotecan-sensitive, MGMT methylated/microsatellite stable (MSS) pretreated mCRC patients.

Patients and methods

Key inclusion criteria were centrally confirmed MGMT methylation by methylation-specific PCR, MSS mCRC, progression after at least two prior chemotherapy regimens for advanced disease and irinotecan-free interval >3 months. TEMIRI (TMZ 150 mg/m2 on days 1-5 plus irinotecan 100 mg/m2 on days 1, 15 q28 days) was administered for six cycles, followed by maintenance with TMZ. The primary end point was overall response rate (ORR). Exploratory translational analyses included MGMT immunohistochemistry (IHC) and methyl-BEAMing (MB).

Results

Between December 2014 and June 2017, 25 patients were enrolled. The primary end point was met, since six patients achieved a partial response [ORR 24%, 95% confidence interval (CI) 11% to 43%]. At a median follow-up of 15.6 months, median progression-free survival (mPFS) and overall survival (mOS) were 4.4 and 13.8 months, respectively. Only four (16%) patients had ≥ grade 3 (CTCAE 4.0) adverse events. All patients whose cancer was MGMT-positive IHC were non-responders. Consistently, patients with MGMT-negative/low tumors had a significantly longer mPFS than others (6.9 versus 2.0 months; hazard ratio = 0.29, 95% CI 0.02-0.41; P = 0.003) and a non-significant trend for longer mOS. MB testing showed similar accuracy.

Conclusions

TEMIRI regimen is a safe and active option in pre-treated, irinotecan-sensitive mCRC patients with MGMT methylation.

RET fusions in a small subset of advanced colorectal cancers at risk of being neglected

Background

Recognition of rare molecular subgroups is a challenge for precision oncology and may lead to tissue-agnostic approval of targeted agents. Here we aimed to comprehensively characterize the clinical, pathological and molecular landscape of RET rearranged metastatic colorectal cancer (mCRC).

Patients and methods

In this case series, we compared clinical, pathological and molecular characteristics of 24 RET rearranged mCRC patients with those of a control group of 291 patients with RET negative tumors. RET rearranged and RET negative mCRCs were retrieved by systematic literature review and by taking advantage of three screening sources: (i) Ignyta's phase 1/1b study on RXDX-105 (NCT01877811), (ii) cohorts screened at two Italian and one South Korean Institutions and (iii) Foundation Medicine Inc. database. Next-generation sequencing data were analyzed for RET rearranged cases.

Results

RET fusions were more frequent in older patients (median age of 66 versus 60 years, P = 0.052), with ECOG PS 1-2 (90% versus 50%, P = 0.02), right-sided (55% versus 32%, P = 0.013), previously unresected primary tumors (58% versus 21%, P < 0.001), RAS and BRAF wild-type (100% versus 40%, P < 0.001) and MSI-high (48% versus 7%, P < 0.001). Notably, 11 (26%) out of 43 patients with right-sided, RAS and BRAF wild-type tumors harbored a RET rearrangement. At a median follow-up of 45.8 months, patients with RET fusion-positive tumors showed a significantly worse OS when compared with RET-negative ones (median OS 14.0 versus 38.0 months, HR: 4.59; 95% CI, 3.64-32.66; P < 0.001). In the multivariable model, RET rearrangements were still associated with shorter OS (HR: 2.97; 95% CI, 1.25-7.07; P = 0.014), while primary tumor location, RAS and BRAF mutations and MSI status were not.

Conclusions

Though very rare, RET rearrangements define a new subtype of mCRC that shows poor prognosis with conventional treatments and is therefore worth of a specific management.

The prognostic impact of primary tumour location in patients with stage II and stage III colon cancer receiving adjuvant therapy. A GISCAD analysis from three large randomised trials

PURPOSE

Because the role of the primary tumour location in the adjuvant setting has not been clearly established in colon cancer, we analysed the clinical outcome according to the primary tumour location from three Italian trials assessing adjuvant therapy in colon cancer.

PATIENTS AND METHODS

Overall survival (OS) and disease-free survival (DFS) were assessed globally and in each trial, according to right-sided, transverse and left-sided primary colon cancer. Analysis was planned to provide overall and stage-specific results.

RESULTS

Individual data of 5239 patients were included in this analysis. The right-sided tumours were 1540 (29%), tumours originating in the transverse were 815 (16%) and left-sided tumours were 2884 (55%). At the multivariate analysis, DFS findings from the comparison of the right-sided versus left-sided tumours (hazard ratio [HR] = 1.00; 95% confidence interval [CI] = 0.89-1.14) were not statistically associated with clinical outcomes in the overall population. On the contrary, OS findings, from the comparison of the right-sided versus left-sided tumours, were significantly associated with outcomes (HR = 1.20; 95% CI = 1.04-1.39). In stage II patients, there was no difference in terms of DFS and OS among the three different tumour locations, whereas in stage III patients, the left-sided tumours showed an improved prognosis in terms of OS (HR: 1.36 95% CI = 1.14-1.62, p < 0.001).

CONCLUSION

This is the largest analysis demonstrating a prognostic effect of the tumour location on patients with colon cancer receiving adjuvant chemotherapy. Nevertheless, the effect is limited to OS in stage III colon cancer. In stage II tumours, the primary location has a lesser impact. The transverse tumours should be prognostically considered in between the right-sided and left-sided tumours.

Medical Treatment of Neuroendocrine Tumors

Background

Tumors of the neuroendocrine system are characterized by amine precursor uptake and decarboxylation, and they represent a heterogeneous group of carcinomas including carcinoids, islet cell carcinomas of the pancreas, medullary thyroid carcinomas and Merkel cell carcinomas. Their similar cytochemical and ultrastructural properties sustain the hypothesis of a common embryologic origin within the neural crest. Many of these tumors grow slowly, and reducing tumor burden represents the treatment of choice. However, when surgery is not feasible, medical treatment has to be considered. Therapeutic approaches in metastatic disease often do not consider the different biologic behaviors of these neoplasms. Moreover, efficacy of the treatment is associated with lack of a clear definition of the type of response: objective, symptomatic or biochemical.

Methods

In this review we have analyzed the different medical approaches used in the treatment of neuroendocrine tumors in an attempt to define their precise role in the different neoplasms.

Results

In carcinoid tumors, immunotherapy and the somatostatin analogue can be efficaciously used for the control of carcinoid syndrome. For inhibition of tumor growth, chemotherapy should be used only in patients with rapidly progressive disease, and the results are still unsatisfactory.

Conclusions

Although all these tumors appear to have similar cytochemical properties, the responsiveness of the various neoplasms is very different. In the future, a specific treatment modality and a clear definition of the type of response (objective, symptomatic or biochemical) need to be defined for each type of neuroendocrine tumor.

Well-Differentiated Neuroendocrine Carcinoma of the Lung: A Case Report

Well-differentiated neuroendocrine carcinoma (WDNC) of the lower respiratory tract displays clinical and radiologic features intermediate between carcinoids and small cell carcinoma and shares some biologic characteristics with both. We describe a case of WDNC resistant to three different treatments. The patient, a 42-year-old woman, received 2 cycles of chemotherapy before coming to our observation, including cyclophosphamide, adriamycin and vincristine, with progression of disease. We administered r-alpha-2a interferon for 2 months, but the patient showed clinical progression. Therefore, streptozotocln associated with epirubicin was utilized, but the patient died of disease progression after 4 cycles and 10 months from the first treatment. The case of WDNC described in this report showed an unusual aggressive clinical course and was refractory to conventional and unconventional treatments. The proper management for WDNC is still unknown. However, according to literature data, the chemotherapeutic schemes employed for small cell lung cancer represent the first treatment choice for WDNC. Further studies are needed to help define treatment strategies according to the biology of the tumor.

Adjuvant Chemotherapy for Cancer of Gastrointestinal Tract: A Critical Review

Surgery is the only curative therapeutic approach for gastrointestinal tumors. If the tumor is deeply Infiltrating through serosa or invading regional lymph nodes, the 5-year patient's survival is about 60 % and < 40 %, respectively. The natural history and prognosis of neoplasms from colon, rectum and stomach are different. Despite the unsatisfactory results obtained with radical treatment of advanced disease, there are positive studies on adjuvant treatment of colon and rectal cancer, whereas the role of such an approach is still controversial for gastric cancer. The combination of fluorouracil containing chemotherapy with radiotherapy was suggested as the most effective adjuvant treatment for patients with Dukes’ B and C rectal cancer. However, the choice of chemotherapeutic regimen is still debated. A recent report, from the North Central Cancer Tumor Group, stated survival and disease-free survival advantages for patients with Dukes’ C colon cancer treated with FU + levamisole for 1 year after radical surgery. Since this regimen was not proven effective in advanced disease, ongoing adjuvant trials are comparing it with the combination of FU + biochemical modulator. The role of adjuvant therapy for gastric cancer is debated. The recent development of regimens active on advanced disease result in more promising future adjuvant trials.

Integrated Treatment with Doxifluridine and Radiotherapy in Recurrent or Primary Unresectable Rectal Cancer. A Feasibility Study

Aims and Background

When combined with radiotherapy, fluoropyrimidines have been shown to have synergistic effects on various tumor types. Doxifluridine (5-dFUR) is a 5-fluorouracil (5-FU) prodrug that is transformed into 5-FU in neoplastic tissue, which suggests that it may improve the activity of radiotherapy. The aims of this study were to evaluate the feasibility and efficacy of the combination of radiotherapy and oral 5-dFUR plus I-leucovorin in terms of pathologically complete remissions in locally advanced rectal cancer.

Methods

Eleven patients with locally recurrent (n = 7) or primary unresectable rectal cancer (n = 4) were treated with three cycles of oral I-leucovorin 25 mg/dose followed by 5-dFUR 750 mg/m2 twice daily for four days every 12, in combination with pelvic radiation at a standard dose of 45 Gy over five weeks. The tumor burden was assessed by means of CT and endoscopic ultrasound at baseline and at least four weeks after the end of the treatment and before surgery.

Results

Four patients achieved an objective response, 6 disease stabilization and 1 had progressive disease. After a median time of five weeks from the end of treatment 8 patients underwent radical resection and a pathologically complete remission was documented in 2. Seven of these patients are still alive and disease free after a median follow-up of 18 months. The major side effects were grade 3 diarrhea in one case, and grade 1-2 nausea and vomiting in three cases. No significant hematological toxicity was observed.

Conclusions

This combination of radiation and 5-dFUR plus I-leucovorin led to an interesting rate of resectability, with pathological downstaging being documented in two cases. These preliminary results show an encouraging local control of an otherwise unresectable disease. Combined preoperative therapy with oral fluoropyrimidine plus I-leucovorin together with radiation may be an attractive approach in patients with operable rectal cancer.