Phase 2, multicenter, open-label basket trial of nab-sirolimus for patients with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 genes (PRECISION I)

TPS597

Background: Albumin-bound ( nab)-sirolimus, a novel mTOR inhibitor (mTORi) that utilizes nanoparticle technology to preferentially target tumors, is approved in the US for the treatment of adults with malignant PEComa. In an exploratory analysis of the AMPECT registrational trial of nab-sirolimus in advanced malignant PEComa (NCT02494570), 8/9 (89%) and 1/5 (20%) patients with TSC1 and TSC2 inactivating alterations, respectively, had confirmed response (Wagner, J Clin Oncol. 2021). Importantly, both TSC1 and TSC2 alterations have been observed in patients with various gastrointestinal cancers (Table). Overall, most treatment-related adverse events (TRAEs) in AMPECT were grade 1/2 and manageable for long-term treatment; no grade ≥4 TRAEs occurred. Methods: PRECISION I (NCT05103358) is a phase 2, open-label, multi-institutional basket trial evaluating efficacy and safety of nab-sirolimus in patients with alterations in TSC1 (Arm A) and TSC2 (Arm B). Patients ≥12 years old with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 (confirmed by central review of next-generation sequencing reports) who have progressed on standard therapies and are mTORi-naïve are eligible. nab-Sirolimus 100 mg/m2 will be administered weekly as an intravenous infusion over 30 minutes on Days 1 and 8 of each 21-day cycle. The primary endpoint is overall response rate determined by independent review using RECIST v1.1; other endpoints include duration of response, disease control rate, time to response progression-free survival by independent radiographic review, overall survival, patient-reported quality of life, and safety. Enrollment is ongoing. The most frequent tumor types expected in this tissue-agnostic trial are bladder, hepatobiliary, endometrial, soft tissue sarcoma, ovarian, and esophagogastric based on the prevalence of TSC1 or TSC2 alterations (Table). Clinical trial information: NCT05103358 . [Table: see text]

Phase 2, multicenter, open-label basket trial of nab-sirolimus for patients with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 genes (PRECISION I)

TPS818

Background: Albumin-bound ( nab)-sirolimus, a novel mTOR inhibitor (mTORi) that utilizes nanoparticle technology to preferentially target tumors, is approved in the US for the treatment of adults with malignant PEComa. In an exploratory analysis of the AMPECT registrational trial of nab-sirolimus in advanced malignant PEComa (NCT02494570), 8/9 (89%) and 1/5 (20%) patients with TSC1 and TSC2 inactivating alterations, respectively, had confirmed response (Wagner, J Clin Oncol. 2021). Importantly, both TSC1 and TSC2 alterations have been observed in patients with various gastrointestinal cancers (Table). Overall, most treatment-related adverse events (TRAEs) in AMPECT were grade 1/2 and manageable for long-term treatment; no grade ≥4 TRAEs occurred. Methods: PRECISION I (NCT05103358) is a phase 2, open-label, multi-institutional basket trial evaluating efficacy and safety of nab-sirolimus in patients with alterations in TSC1 (Arm A) and TSC2 (Arm B). Patients ≥12 years old with malignant solid tumors harboring pathogenic inactivating alterations in TSC1 or TSC2 (confirmed by central review of next generation sequencing reports) who have progressed on standard therapies and are mTORi-naïve are eligible. nab-Sirolimus 100 mg/m2 will be administered weekly as an intravenous infusion over 30 minutes on Days 1 and 8 of each 21-day cycle. The primary endpoint is overall response rate determined by independent review using RECIST v1.1; other endpoints include duration of response, disease control rate, time to response, progression-free survival by independent radiographic review, overall survival, patient-reported quality of life, and safety. Enrollment is ongoing. The most frequent tumor types expected in this tissue-agnostic trial are bladder, hepatobiliary, endometrial, soft tissue sarcoma, ovarian, and esophagogastric based on the prevalence of TSC1 or TSC2 alterations (Table). Clinical trial information: NCT05103358 . [Table: see text]

Combination Dabrafenib and Trametinib Versus Combination Nivolumab and Ipilimumab for Patients With Advanced BRAF-Mutant Melanoma: The DREAMseq Trial-ECOG-ACRIN EA6134

PURPOSE

Combination programmed cell death protein 1/cytotoxic T-cell lymphocyte-4-blockade and dual BRAF/MEK inhibition have each shown significant clinical benefit in patients with BRAFV600-mutant metastatic melanoma, leading to broad regulatory approval. Little prospective data exist to guide the choice of either initial therapy or treatment sequence in this population. This study was conducted to determine which initial treatment or treatment sequence produced the best efficacy.

PATIENTS AND METHODS

In a phase III trial, patients with treatment-naive BRAFV600-mutant metastatic melanoma were randomly assigned to receive either combination nivolumab/ipilimumab (arm A) or dabrafenib/trametinib (arm B) in step 1, and at disease progression were enrolled in step 2 to receive the alternate therapy, dabrafenib/trametinib (arm C) or nivolumab/ipilimumab (arm D). The primary end point was 2-year overall survival (OS). Secondary end points were 3-year OS, objective response rate, response duration, progression-free survival, crossover feasibility, and safety.

RESULTS

A total of 265 patients were enrolled, with 73 going onto step 2 (27 in arm C and 46 in arm D). The study was stopped early by the independent Data Safety Monitoring Committee because of a clinically significant end point being achieved. The 2-year OS for those starting on arm A was 71.8% (95% CI, 62.5 to 79.1) and arm B 51.5% (95% CI, 41.7 to 60.4; log-rank P = .010). Step 1 progression-free survival favored arm A (P = .054). Objective response rates were arm A: 46.0%; arm B: 43.0%; arm C: 47.8%; and arm D: 29.6%. Median duration of response was not reached for arm A and 12.7 months for arm B (P < .001). Crossover occurred in 52% of patients with documented disease progression. Grade ≥ 3 toxicities occurred with similar frequency between arms, and regimen toxicity profiles were as anticipated.

CONCLUSION

Combination nivolumab/ipilimumab followed by BRAF and MEK inhibitor therapy, if necessary, should be the preferred treatment sequence for a large majority of patients.

Persistent Disparities in Adult Hematopoietic Cell Transplantation

The use of large databases has provided advancements in the understanding of racial, ethnic, and socioeconomic disparities in the field of adult hematopoietic cell transplants (HCT). Disparities exist on individual, institutional, and systemic levels for both allogeneic and autologous HCT. We reviewed the most recent publications that utilized large databases to elucidate disparities in HCT and placed them into historical context of the other major studies in the field. Two emerging themes were identified. These themes are persistent inequalities in both allogeneic HCT and autologous HCT for myeloma and the importance of improving homogeneity of care in HCT. Minimization of inequalities can be achieved only with an understanding of the persistent barriers that exist in the field.

Neoadjuvant treatment of Dermatofibrosarcoma Protuberans of pancreas with Imatinib: case report and systematic review of literature

Dermatofibrosarcoma Protuberans (DFSP) is a rare skin tumor, characterized by frequent local recurrence but is seldom metastatic. It is histologically characterized by storiform arrangement of spindle cells. Cytogenetically, most tumors are characterized by translocation 17:22 leading to overexpression of tyrosine kinase PDGFB which can be targeted with tyrosine kinase inhibitor, Imatinib. We describe the first case of unresectable pancreatic metastases from DFSP treated with neoadjuvant Imatinib and subsequently R0 metastectomy. Additionally, a comprehensive systematic review of DFSP pancreatic metastases and the current published data on the use of Imatinib in DFSP is summarized.

Upper urinary tract carcinoma in Lynch syndrome cases

PURPOSE

Patients with Lynch syndrome are much more likely to have generally rare upper urinary tract urothelial carcinoma but not bladder urothelial carcinoma. While the risk has been quantified, to our knowledge there is no description of how this population of patients with Lynch syndrome and upper urinary tract cancer differs from the general population with upper urinary tract cancer.

MATERIALS AND METHODS

We obtained retrospective data on a cohort of patients with Lynch syndrome from the Hereditary Cancer Center in Omaha, Nebraska and compared the data to those on a control general population from western Sweden. These data were supplemented by a new survey about exposure to known risk factors.

RESULTS

Of the patients with Lynch syndrome 91% had mutations in MSH2 rather than in MSH1 and 79% showed upper tract urothelial carcinoma a mean of 15.85 years after prior Lynch syndrome-type cancer. Median age at diagnosis was 62 years vs 70 in the general population (p <0.0001). Only half of our patients had a significant smoking history and the male-to-female ratio was 0.95. Of patients with Lynch syndrome 51% had urothelial carcinoma in the ureter while it occurred in the renal pelvis in 65% of the general population (p = 0.0013). Similar numbers of high grade tumors were found in the Lynch syndrome and general populations (88% and 74%, respectively, p = 0.1108).

CONCLUSIONS

Upper urinary tract tumors develop at a younger age and are more likely to be in the ureter with an almost equal gender ratio in patients with Lynch syndrome. It has high grade potential similar to that in the general population.