The L 98-59 System: Three Transiting, Terrestrial-Size Planets Orbiting A Nearby M Dwarf

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L 98-59 (TOI-175, TIC 307210830)—a bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the corresponding stellar parameters yield planet radii ranging from 0.8 R⊕ to 1.6 R⊕. All three planets have short orbital periods, ranging from 2.25 to 7.45 days with the outer pair just wide of a 2:1 period resonance. Diagnostic tests produced by the TESS Data Validation Report and the vetting package DAVE rule out common false-positive sources. These analyses, along with dedicated follow-up and the multiplicity of the system, lend confidence that the observed signals are caused by planets transiting L 98-59 and are not associated with other sources in the field. The L 98-59 system is interesting for a number of reasons: the host star is bright (V = 11.7 mag, K = 7.1 mag) and the planets are prime targets for further follow-up observations including precision radial-velocity mass measurements and future transit spectroscopy with the James Webb Space Telescope; the near-resonant configuration makes the system a laboratory to study planetary system dynamical evolution; and three planets of relatively similar size in the same system present an opportunity to study terrestrial planets where other variables (age, metallicity, etc.) can be held constant. L 98-59 will be observed in four more TESS sectors, which will provide a wealth of information on the three currently known planets and have the potential to reveal additional planets in the system

Randomised controlled trial of methotrexate for chronic inflammatory demyelinating polyradiculoneuropathy (RMC trial): a pilot, multicentre study

BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) responds to treatment with corticosteroids, intravenous immunoglobulin, and plasma exchange. We aimed to test whether the standard immunosuppressive drug methotrexate was of use in treatment of CIDP. METHODS: In a pilot, multicentre, randomised, double-blind, controlled trial we compared oral methotrexate 7.5 mg weekly for 4 weeks, then 10 mg weekly for 4 weeks, and finally 15 mg weekly for 32 weeks (40 weeks' total treatment) with placebo in patients with CIDP requiring intravenous immunoglobulin or corticosteroids. After about 16 weeks, the dose of corticosteroids or intravenous immunoglobulin was decreased by 20% every 4 weeks if participants did not deteriorate. Primary outcome was a greater than 20% reduction in mean weekly dose in the last 4 weeks of the trial compared with the first 4 weeks. Secondary outcomes analysed separately at the mid-trial and final visits measured activity limitations and strength. Analyses were done by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN73774524. FINDINGS: 59 of the 60 enrolled participants completed the trial. 14 (52%) of 27 taking methotrexate and 14 (44%) of 32 taking placebo had a greater than 20% reduction in mean weekly dose of corticosteroids or intravenous immunoglobulin (adjusted odds ratio 1.21, 95% CI 0.40-3.70). There were no clinically and statistically significant differences in secondary outcomes. The one serious adverse event in the placebo group and the three in the methotrexate group were not thought to be related to treatment. INTERPRETATION: Oral methotrexate 15 mg weekly showed no significant benefit, but limitations in the trial design and the high rate of response in the placebo group meant that a treatment effect could not be excluded. This study can inform design of future trials in CIDP. FUNDING: The GBS/CIDP Foundation International