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Tin is an indispensable metal in the modern industry. The current tin smelting processes, however, have the disadvantages of high smelting temperature, long smelting time, especially high tin loss ratio (>10 wt%). The tin loss attributes to the volatilization as gaseous SnO and stannous silicate (SnO?SiO2) residual in the slag. An innovative approach for preparing metallic tin effectively from cassiterite in the presence of Na2CO3, named gas-based reduction roasting followed by water leaching process, is under development in Central South University, China. The present study, using chemically pure SnO2 and SiO2, aims to determine the impact of Na2CO3 on the metallic tin preparation from cassiterite by the novel process using XRD, SEM-EDS, chemical analysis, etc. It was found that Na2CO3 effectively restrained the tin volatilization as SnO and the formation of hardly reductive SnO?SiO2 during the reduction roasting process. In the presence of Na2CO3, most of SnO2 in the raw materials (mixture of SnO2+SiO2) was directly reduced to metallic tin, and part of SnO2 reacted with Na2CO3 to form intermediate Na2SnO3, which was then reduced to metallic tin. The SiO2 was transformed into Na2SiO3 and then went into the water solution in the following water-leaching process. The main reactions of the SnO2 + SiO2 system in the presence of Na2CO3 under reductive atmosphere were ascertained.

Background: The KRAS G12C mutation is found in approximately 14% of lung adenocarcinoma and 11% of NSCLC pts. Currently, no approved therapy targets this mutation. AMG 510 is a novel small molecule that specifically and irreversibly inhibits KRAS G12C by locking it in an inactive GDP-bound state. Method: A phase 1, first-in-human, open-label, multicenter study (NCT03600883) is evaluating the safety, tolerability, PK, and efficacy of AMG 510 in adult pts with locally-advanced or metastatic KRAS G12C mutant solid tumors, including NSCLC pts. Safety is the primary endpoint; ORR (assessed every 6 wks), DOR, PFS, and PK are key secondary endpoints. Important inclusion criteria: KRAS G12C mutation identified through DNA sequencing; measurable or evaluable disease; progression on standard therapy; ECOG PS 2; life expectancy >3 mo. Important exclusion criteria: active brain metastases; myocardial infarction within 6 mo. The maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) will be identified during the dose exploration. Once identified, additional pts with advanced solid tumors carrying the KRAS G12C mutation will be enrolled during dose expansion. AMG 510 is given PO until disease progression, intolerance, or consent withdrawal. Result: As of 4 April 2019, thirteen [5 men and 8 women; median age 63 yrs (range: 53e77)] of 35 pts enrolled in 4 dose exploration cohorts have NSCLC. These pts had a median of 3 (range: 1e5) prior lines of treatment (tx). On-study tx duration had a median of 59 days (range:9e192 d). No DLTs have been reported. Six NSCLC pts reported 10 treatment-related AEs (6 grade 1; 2 grade 2; 2 grade 3). The grade 3 related AEs were anemia in a pt with baseline grade 2 anemia and diarrhea lasting 2 d in a second pt. The most frequently reported AEs were decreased appetite (n¼4 subjects) and diarrhea (n¼3 subjects). Best tumor response has been evaluated in 10 NSCLC pts; 3 pts have not reached their first assessment. Of these 10 evaluable pts, 5 pts had a PR (2 of which are confirmed PRs), 4 had SD and 1 had PD. Of 13 NSCLC pts, 11 pts remain on-study and continue their AMG 510 and 2 pts have discontinued treatment due to PD during study wks 6 and 26. Conclusion: AMG 510 has been well tolerated at all 4 dose levels explored and has shown antitumor activity when administered as monotherapy to pts with advanced KRAS G12C mutant NSCLC. Enrollment is on-going.

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