For whatever reason, there are two series matrix files - it could be related to the 2 different array versions (GPL15078 and GPL15079). This is also GenePix data, which is not as well supported as the typical Affymetrix, Agilent, and Illumina chips.

You can download the series matrices and then import them separately. Thereafter, I guess that you could bind them together in some way:

wget https://ftp.ncbi.nlm.nih.gov/geo/series/GSE34nnn/GSE34810/matrix/GSE34810-GPL15078_series_matrix.txt.gz
wget https://ftp.ncbi.nlm.nih.gov/geo/series/GSE34nnn/GSE34810/matrix/GSE34810-GPL15079_series_matrix.txt.gz

In R:

require(GEOquery)

gset1 <- getGEO(filename = 'GSE34810-GPL15078_series_matrix.txt.gz', GSEMatrix = TRUE)
Parsed with column specification:
cols(
  ID_REF = col_double(),
  GSM855696 = col_double(),
  GSM855697 = col_double(),
  GSM855698 = col_double()
)


gset2 <- getGEO(filename = 'GSE34810-GPL15079_series_matrix.txt.gz', GSEMatrix = TRUE)
Parsed with column specification:
cols(
  ID_REF = col_double(),
  GSM855699 = col_double(),
  GSM855700 = col_double(),
  GSM855701 = col_double(),
  GSM855702 = col_double(),
  GSM855703 = col_double(),
  GSM855704 = col_double(),
  GSM855705 = col_double(),
  GSM855706 = col_double(),
  GSM855707 = col_double()
)

It also appears that this data is already normalised and log [base 2] transformed:

par(mfrow = c(1,2), mar = c(6,2,2,2))
boxplot(exprs(gset1))
boxplot(exprs(gset2), las = 2)

-----------------------

The other option is to retrieve the raw data GPR files and normalise them together using limma

Kevin