Hi, welcome to healthcare magic, I am sorry that your husband feels unwell

Unintentional weight is concerning and requires through investigations.
The possible causes of weight loss would include: (1) inadequate nutrition or increased physical activity
(2) hyperthyroidism- the thyroid which plays a part in metabolism, is over active
(3) chronic or longstanding diarrhoea
(4) depression
(5) infection
(6) cancer
(7) HIV/AIDS
(8) smoking
(9) uncontrolled diabetes
(10) systemic diseases such as kidney or liver disease

You stated that he already had a CBC done though the results that you have included are a little unclear.
Your husband's doctor would likely ask (1) the amount and time period of the weight loss
(2) the presence of any additional symptoms
(3) any history that could be related to any of the conditions mentioned above such as pr bleeding, abdominal pain, constipation,vomiting, history of smoking, history of exposure to any toxins, history of palpitations or heat intolerance, history mouth sores, medication , increased thirst or urination, depression

Investigations that may be done include: CBC- which was already done, ESR which is a non specific indicator of inflammation in the body- if elevated it will tell you that you need to look closer, Liver and kidney function test, serum protein electrophoresis which would identify a cancer of the bone, calcium, magnesium and proteins which can also reflect significant abnormalities.
Imaging has been started with the CT scan (unsure of where) , can also consider imaging of the gastrointestinal tract and if not already done the chest since he has chest pain.

I hope this information is helpful to you and I hope your husband finds out the cause of his weight loss