SET LANGUAGE Russian;

  create table #t 
  (
     ID numeric (15,0)
    ,Name varchar(140)
    ,MDate datetime
  )

insert into #t
(ID, Name, Mdate) VALUES
(648, 'aaa', '01.03.2019 0:00:00'), 
(608, 'bbb', '10.03.2019 0:00:00'), 
(557, 'ccc', NULL), 
(557, 'ccc1', '09.03.2019 0:00:00'), 
(557, 'ccc', '15.03.2019 0:00:00'), 
(557, 'ccc', '20.03.2019 0:00:00'), 
(557, 'ccc1', '25.03.2019 0:00:00')
;

SELECT * FROM 
(
	SELECT TOP 1 WITH TIES * FROM 
	(
		SELECT * FROM 
		(
			SELECT ID, Name, Mdate, LEAD(Name, 1) OVER (PARTITION BY ID ORDER BY Mdate ASC) AS Name_Lead  FROM #t
		) a
		WHERE Name_Lead IS NULL OR Name <> Name_Lead OR (Name IS NULL AND Name_Lead IS NOT NULL) 
	) b
	ORDER BY ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Mdate DESC)
) c 
ORDER BY ID, Mdate DESC;
GO 

DROP TABLE #t