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California Research Advisory Panel

Cannabis Therapeutic Program


Results of Study with Smoked Marijuana

The Protocols. Three protocols were developed based on experiences since March of 1980: Protocol IV, Revised Operational Protocol for Smoked Marijuana, and Revised Protocol for Smoked Marijuana (Appendix IX).

The initial Smoked Marijuana Protocol (Protocol IV) was limited to inpatients who were experienced marijuana smokers and receiving Cisplatin, Dacarbazine and/or 5-Azacytadine.

In 1981, the Smoked Marijuana Protocol was modified to permit outpatients and marijuana naive' patients to participate. In addition, patients receiving radiation therapy were then allowed to use smoked marijuana.

In 1983, another revision was made to adapt to the limited number of patients choosing to use smoked marijuana. This protocol allowed all patients, regardless of their anticancer treatment, to have access to smoked marijuana. A standardized smoking technique was described and the use of a water pipe was encouraged to modify the harshness of the smoke which was a deterrent for patients using smoked marijuana in the previous protocols.

Minimal Accrual. The marijuana cigarette protocol attracted only 119 patients, less than five percent of the total number enrolled in the Cannabis Therapeutic Program. Anecdotal reports suggested that reasons for the low accrual included a general objection to smoking on the part of some patients, their oncologists, or their hospitals, and some reluctance to use a drug associated with street use.

The characteristics of the NIDA cigarettes may have been a factor in discouraging further use by experieced marijuana smokers. The cigarettes, even after proper storage, were dry and gave an acrid smoke. Their potency was noticeably low at a time when street marijuana was increasing greatly in potency and availability.

Data Collection. As each protocol was changed data forms were also revised in an effort to increase enrollment by reducing any burden of paperwork for investigators and patients. All data forms associated with the various protocols are included in the appendices.

The report form included with the latest revision of the protocol (2/11/83) requested only information which was considered essential and, for the purpose of this evaluation, data from the previous forms were transcribed to the newer form for consistency in coding. This point is elaborated in a following section on validity of results.

Potency Increase. The potency of the marijuana cigarettes being used was changed in April of 1983 from 1.2% to 2.8% THC content. This increase was not considered in our analysis.

Patients. The Panel received 218 treatment episode reports for 119 total patients treated with smoked marijuana. Eight reports were received for 3 patients treated with both smoked marijuana and THC capsules. Twenty-one of the 119 patients had been previously treated under other Cannabis Therapeutic Program protocols. Reports on 98 patients are therefore available for analysis of the 'first treatment episode' on the Cannabis Therapeutic Program. Table U reflects characteristics of the 98 patients whose reports are analyzed and Table V summarizes the primary tumor sites.

Evaluation of the Antiemetic Properties. As shown in Table W, only 4.1% of the patients reported mild or no nausea during their first smoked marijuana protected treatment episode. And, 46.72 reported vomiting of 3 times or less during their first treatment episode.

Overall assessment of the effectiveness was rated very or moderately successful by 58.7%. The relative effectiveness of smoked and orally ingested THC are similar. Table X includes the column on THC capsules from Table R for comparison. Anecdotal reports by a few patients who had used both marijuana cigarettes and THC, rated the effectiveness of the smoked marijuana as comparable to that of the oral THC used in this study.

Side Effects. Side effects are reported in Table Y which also presents the data on THC alone (from Table S) for comparison. The slightly more intense side effects after smoked marijuana are not surprising in view of its more rapid onset. Presumably, they persisted for a shorter time but no such measurements were recorded in this study.

Table U

Characteristics of Study Population

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

n - 98

No. Percent

Sex ---- -------

Male 56 57.1

Female 42 42.9

Age Distribution

19 yrs or less 1 1.0

20 - 39 yrs 38 38.8

40 - 59 yrs 32 32.7

60 yrs or more 27 27.6

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

Table V

Distribution of Patient Cancer History

by Primary Site

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

n 98

Primary Cancer Site Number Percent

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

Hodgkin's 5 5.1

Other lymphomas 3 3.1

Myeloid leukemia 2 2.0

Tongue 1 1.0

Esophagus 1 1.0

Liver and intrahepatic ... 3 3.1

Gallbladder and ducts 1 1.0

Pancreas 1 1.0

Retroperitoneal 2 2.0

Other and ill defined 1 1.0

Nasal cavities 1 1.0

Trachea, bronchi 18 18.4

Thymus, heart 3 3.1

Bone and articulations 5 5.1

Connective and .... 2 2.0

Melanoma of skin 4 4.1

Female breast 5 5.1

Ovary and other .... 14 14.3

Prostate 4 4.1

Testis 18 18.4

Bladder 2 2.0

Without specific 2 2.0

Table W

Comparative Ratings of Nausea and Vomiting

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

Smoked Marijuana THC used alone

n 98 n 257

Ratings of No. % No. %

Nausea

None 9 9.2 38 15.1

Mild 34 34.7 85 33.9

Moderate 36 36.7 73 29.1

Severe 17 17.3 55 21.9

Missing 2 2.0 6 2.3

Vomiting

None 19 19.4 89 35.3

1 - 3 times 36 36.7 69 27.4

4 - 6 times 18 18.4 35 13.9

> 6 times 24 24.5 59 23.4

Missing 1 1.0 5 1.9

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




Table X

Comparative Ratings of Overall Effectiveness

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

Smoked Marijuana THC used alone

n - 98 n - 257

No. % No. %

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

Not effective 26 26.8 62 24.7

Slightly 14 14.4 45 17.9

Moderately 40 41.2 68 27.1

Very 17 17.5 76 30.3

Missing 1 1.0 6 2.3

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

Table Y

Comparative Ratings of Side Effects

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

Smoked THC

Marijuana used

alone

n 98 n 257

No. No.

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

Incidence of

Side Effects

Dry mouth

Severe 4 4.3 4 1.6

Moderate 26 27.7 31 12.4

Mild 23 24.5 77 30.8

None 41 43.6 138 55.2

Missing 4 7

Tachycardia

Severe 2 2.1

Moderate 1 1.1 6 2.4

Mild 3 3.2 19 7.6

None 88 93.6 225 90

Missing 4 7

Ataxia

Severe 1 1.1 1 0.4

Moderate 9 9.6 4 1.6

Mild 6 6.4 26 10.4

None 78 83.0 219 87.6

Missing 4 7

Dizziness

Severe 4 4.3 5 2

Moderate 12 12.8 16 6.4

Mild 15 16.0 46 18.4

None 63 67.0 183 73.2

Missing 4 7

Orthostatic

hypotension

Severe 2 2.1 1 0.4

Moderate 2 2.1 4 1.6

Mild 3 3.2 27 10.8

None 67 71.3 218 87.2

Missing 4 7

Anxiety

Severe 3 3.2 7 2.8

Moderate 8 8.5 8 3.2

Mild 8 8.5 32 12.8

None 75 79.8 203 81.2

Missing 4 7

Table Y (Cont.)

Smoked THC

Marijuana used

alone

No. No.

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

Sedation

Severe 2 2.1 13 5.2

Moderate 25 26.6 46 18.4

Mild 22 23.4 101 40.4

None 45 47.9 90 36

Missing 4 7

Elated mood

Severe 1 1.1 6 2.4

Moderate 10 10.6 22 8.8

Mild 14 14.9 33 13.2

None 61 64.9 189 75.6

Missing 4 7

Confusion

Severe 4 4.3 2 0.8

Moderate 10 10.6 30 12

Mild 9 9.6 47 18.8

None 71 75.5 171 68.4

Missing 4 7

Distortion of

perception

Severe 3 3.2 2 0.8

Moderate 7 7.4 12 4.8

Mild 5 5.3 43 17.2

None 79 84.0 193 77.2

Missing 4 7

Fantasizing

Severe

Moderate 4 4.3 7 2.8

Mild 6 6.4 22 8.8

None 84 89.4 221 88.4

Missing 4 4.3 7

Depressed mood

Severe 3 3.2 3 1.2

Moderate 4 4.3 11 4.4

Mild 10 10.6 19 7.6

None 77 81.9 217 86.8

Missing 4 7

Panic or fear

Severe 3 3.2 3 1.2

Moderate 3 3.2 4 1.6

Mild 1 1.1 12 4.8

None 87 92.6 231 92.4

Missing 4 7

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

Patient Drop-out Rates. Thirtyfour patients continued on to two or more treatment episodes using smoked marijuana. Sixty-four patients dropped from the study. The reasons for dropping are detailed below in Table Z.

Reliability Estimate of Results. There were three basic concerns regarding the reliability of the marijuana protocol results: 1) the change in the data forms, 2) the change in the protocols themselves, and 3) the change in the potency of the marijuana cigarettes. Each of these may influence the kind of data reported.

Since the potency changed from 1.2% to 2.8% THC, any patients smoking marijuana after April 1983, were smoking marijuana that was roughly twice as potent. This may or may not have been considered by the prescribing physician and/or pharmacist in calculating and marking the dosage. There was general confusion about how to calculate dose. Sometimes the number of cigarettes used was listed. Also, patients not smoking the entire dose may not have had this fact recorded, and there was variation in smoking technique.

In 1983, eligibility requirements were changed to permit outpatients and inexperienced marijuana smokers to participate. The smoking method was changed, increasing the amount of time the smoke is held in the lungs. Water pipes were also permitted.

With each protocol change there were changes in the data forms. The original data form had different labels on the side effect


Table Z

Reasons for Termination

After First Treatment Episode

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

n - 64

No. of Patients Percent

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

Ineffective as

an antiemetic 17 26.6

Side effects

too severe 7 10.9

Expired or

completed treatment 32 50

Other 8 12.5

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

categories (none, tolerable, intolerable). More than one treatment episode could be reported on one form. Also, the patient reports had categories dealing with mood. The next data form revision changed the category labels of side effects to none, moderate and severe. One treatment episode was reported per form. Mood was deleted from the patient reports. The final revision is the one sheet form.

The protocol directed that four doses of marijuana should be administered prior to chemotherapy, but the data form also provided a place to enter the actual number of 'doses prior' as 'other.' The patient evaluation form was discontinued and the investigator (or his/her staff) evaluated the nausea, vomiting and overall effectiveness. In tabulating the data the physician's assessment was used. The number of side effect categories was increased to four: none, mild, moderate, and severe. The mean value of patient reports was used. If it fell between categories, it was rounded up when converted to the new form. The dosage level was a fixed choice.

The coding process attempted to take into consideration these changes and standardized the data onto the one page data collection form (Treatment Report Form A).

Protocol Exceptions (Pilot Protocols)

Protocols initially available under the Cannabis Therapeutic Program were limited to antinauseant use of delta-9-tetrahydrocannabinol (THC) to patients undergoing chemotherapy for cancer. In 1983, the Panel began to receive requests for THC from physicians with patients who suffered intractable nausea and vomiting from conditions other than chemotherapy. These patients did not meet the strict criteria of the Panel's other protocols, but needed an alternative to the standard treatments available for nausea and vomiting. THC was considered to be their antiemetic of last resort. The "pilot protocols' provided a treatment option for desperate patients unresponsive to standard treatments.

By the end of the study, 29 patients, all seriously ill, had been approved to receive THC as an antiemetic treatment of last resort. Two patients did not receive drug treatment.. A total of 28 reports of treatment episodes were received; one patient received two THC treatments. Conditions for which THC was tried as an antiemetic included acute leukemia, acute myelocytic leukemia, bone marrow transplant, terminal melanoma, terminal breast cancer, AIDS, multiple sclerosis, etc.

In summary, physicians rated the overall antiemetic effectiveness of THC as very effective for fourteen treatments, moderately effective for five treatments, slightly effective for two treatments and not effective for seven treatments. Other notable THC benefits reported included improved appetites, an increased ability to participate in family functions and an overall improvement in spirits. No serious side effects were reported.

Results of the Controlled Study Protocols

THC plus Transdermal Scopolamine. A two arm placebo controlled study was intended to test the hypothesis that antiemetic therapy with THC would be optimized by combining its use with transdermal scopolamine, (Transderm V). The purpose of the study was to determine antiemetic efficacy, side effects and drop out rate of the combination regimen versu's THC alone using the cumulative, low dose regimen. The investigation was limited to 5 investigators at selected clinical sites. The Panel hoped to establish statistical significance early by means of sequential analysis, anticipating 30 to 50 patients.

The Transderm V Protocol began in late 1983, and continued into 1986. Sixty-five patients were enrolled in this study. However, no conclusion about efficacy was possible by the end of the Cannabis Therapeutic Program, since only ten of the 65 patients who enrolled met the stringent study criteria and completed both arms of the study.

THC in Combination with Dexamethasone. The Dexamethasone Protocol like the Transderm Protocol above was also a two arm placebo controlled study. It was intended to test the hypothesis that antiemetic therapy with THC would be optimized by combining its use with dexamethasone.

The Dexamethasone Protocol also was initiated in late 1983, and continued into 1984; however, of the four patients who entered the study only one patient completed the necessary two trials.

Delta-8-tetrahydrocannabinol (delta-8-THC), a synthetic cannabinoid, is not present in natural marijuana. It is similar in action to delta-9-THC, the oral THC administered in the Cannabis Therapeutic Program, but some reports in the medical literature suggested that it caused fewer central nervous system side effects than delta-9-THC. Because side effects may limit the maximum tolerated dose and may deter some patients from continuing THC therapy even though it may be relieving nausea and vomiting, such properties of delta-8-THC could offer a major advantage. The Panel was encouraged in the effort by Dr. Perez-Reyes, author of some of the studies referred to above.

The Panel engaged Dr. Perez Reyes to consult in developing a pilot research project on the effects of delta-8-THC as an., antiemetic. 'In October 1983, the Panel submitted an investigational New Drug Application (IND 124,094) to the U.S. Food and Drug Administration. Patients were first enrolled in October 1983.

Only ten patients were enrolled in this study. Results on this small number cannot be interpreted except anecdotally. The drug was used on two patients over a longterm period resulting in the following comments:

Patient D received 26 treatment episodes over a 10 month period. After her initial three treatments, during which the patient rated delta-8-THC moderately or very effective, the drug dosing schedule was modified to a single 20mg. dose. The patient continued to benefit. For the next 20 treatment episodes with this modified dose, she rated the drug very effective for 17 treatments, had no or only mild nausea and vomiting, and suffered only dry mouth and sedation as side effects. (Overall effectiveness ratings were missing from three treatment episodes.) However, during treatment episode number 23, the patient experienced anxiety and said she felt 'funny or crazy.' To minimize these effects, the dose was lowered to 10mg. for treatments 24 to 26. The-drug was rated very effective for treatment 24 but not effective for treatments 25 and 26. The protocol nurse had not indicated any change in the patient's chemotherapy regimen or concurrent medications during those treatment episodes. The patient elected not to take further delta-8-THC.

Patient Z received twelve treatments over a total of 5 months (2 months with delta-8-THC, 2 months off the drug while undergoing radiation therapy, then a return to 3 months with delta-8-THC). Delta8-THC was rated as beneficial with a variety of combinations of chemotherapy agents (BCKU + CYC + VCR; ADR; CYC + VCR). The patient rated the drug very effective for 5 treatment episodes and moderately effective for 6. Several side effects were experienced during all treatment episodes, but all were reported as mild. However, on the patient's last treatment, he began a new chemotherapy regimen (ARA-C + MTX) and found delta-8-THC not effective.

Glaucoma Protocol

In 1983, the Legislature considered anecdotal reports from a few patients with glaucoma, and other individuals, and noted the evidence that oral THC and smoked marijuana lowered intra-ocular pressure. In response, the legislation that extended the Cannabis Therapeutic Program also mandated exploration of the therapeutic potential of cannabinoids in glaucoma, an assignment with complexities beyond those encountered in the cancer chemotherapy program.

Prior to designing a clinical trial, the Panel co-opted the services of an ophthalmologist and distributed a questionnaire that queried every ophthalmologist in the State about the probable availability of patients and for their suggestions. The Panel then prepared-and submitted an application for an Investigational New Drug Exemption (IND), accepted by the Food and Drug Administration as 123,373, that included a protocol (Appendix XIII) for the evaluation of oral-THC and smoked marijuana in the treatment of open-angle glaucoma.

In preparing this protocol, the Panel considered the nature of the disease and the availability of other treatment in establishing criteria for the acceptance of patients into the program.

There are several variants of glaucoma. All are characterized by an elevation of the pressure within the eyeball, where pressure is transmitted to the optic nerve with, consequently, a possible loss of vision. However, the rate of progression, threat to vision and modes of treatment differ for different types of glaucoma. Moreover, effective treatment with drugs or, in a few situations, surgery, is available for most patients, a contrast with the nausea and vomiting of cancer chemotherapy.

To be certain that no patient was deprived of treatment of established efficacy by the research needs of the Panel, patients were accepted only if they had open-angle glaucoma inadequately controlled by conventional, non-investigational treatment. To be certain that the desire of the patient to use THC was not generated by emotion or by proselytizing efforts directed toward 'legalized' marijuana, a "Patient Qualification Review Board' was established to scrutinize the medical history of each prospective patient to ensure that their enrollment was appropriate.

In 1984, the Panel conducted a vigorous program to publicize the Panel's investigational glaucoma treatment to ophthalmologists and prospective patients. In addition to the usual press releases, every ophthalmologist received a mailing. The Panel arranged a program at Grand Rounds at the University of California Medical School in San Francisco for 200 ophthalmologists in Northern California and contacted individual doctors known for their special interest or influence.

Nevertheless, by the end of the program, only twenty ophthalmologists were approved as investigators and, of the twelve patients who expressed interest, only nine received treatment. All nine were Mend-stage glaucoma' for whom it was felt that no other treatment alternatives could be offered. All nine chose oral THC rather than smoked marijuana.

Results. The results of treatment can be quickly summarized because all nine patients withdrew from treatment. Four withdrew because of side effects at 3 weeks, 2 months, and five months (2); one for lack of efficacy (4 months); two progressed to cataract extraction and did not resume treatment (5 months, 9 months); one changed doctors (15 months) and one concluded after 7 months that the drug was no longer needed, a conclusion not shared by the doctor.

These patients did, however, contribute information in two areas.

Side Effects. These patients provided reassurance about chronically administered THC in that they took doses ranging from 2.5 to 17.5mg four tim es each day for 1-9 months. The patient who took THC for 9 months used gradually increasing amounts until she was taking 17.5mg four times each day. The most frequent side effects were dry mouth, sedation, ataxia and dizziness. The impression was that the side effects lessened with continued treatment. No serious or unexpected reactions were seen...

Effect on Intra-ocular

Pressure. The doctor's judgement of the patient's clinical status did not provide any evidence of effectiveness although some initial, but not lasting, improvement was claimed.

The measurement of intra-ocular pressure (IOP) should provide an objective measure of drug effect, but variability was somewhat greater than expected, possibly because the measurement was made at varying times after the application of the standard treatment, which was continued when the THC was started. Some of the patients showed an initial decrease in IOP from base line levels, but this lowering was sustained in only two patients. Even in these two patients, the possibility is that THC, an anxiety relieving drug, or the increased attention of the drug trial increased patient compliance with their standard treatment.

Post Marketing Survey of Investigators

Eighteen months after dronabinol reached the market, the Panel decided to audit its function and survey the use of THC as a marketed drug. To accomplish these goals, a survey was mailed to 237 oncologists-investigators. A reminder postcard was mailed one week later and a 622 (n-148) response rate was achieved.

Prescribing of Dronabinol. The survey asked to what extent dronabinol had been prescribed over the 18 months since it became available. Of the respondents, 103 (70%) indicated that they had continued to prescribe tetrahydrocannabinol as dronabinol. The other 45 (302) indicated they had not ordered THC since they prescribed it under the Cannabis Therapeutic Program.

Those investigators who reported that they had not used commercial dronabinol were also the investigators who had treated fewer patients with investigational THC during the program. The 45 investigators who are not using THC had treated only 304 patients during the Cannabis Therapeutic Program (average of 6.8 patients each). The 103 who now use dronabinol had treated 1163 patients during the Cannabis Therapeutic Program (average of 11.3 patients each). The survey shows a tendency for those oncologists who used experimental THC more extensively during the Panel's compassionate access program to continue to prescribe dronabinol.

The survey instrument was intended to establish the factors responsible for restricted use: efficacy, undesirable side effects, price, the triplicate prescription form requirement, and the strict limitations of the FDA approved package insert.

Table A& summarizes the respondents' responses to this question. Physicians who did not order THC cited side effects, ineffectiveness and availability of other effective antiemetics (reported most often as a comment) as reasons for not prescribing dronabinol. Those using THC for their patients included cost and triplicate form requirement as the primary concerns and causes of limited use.

The influence of patient demand on prescribers is reported in Table AB. Those who do not order THC are not influenced by patient demand.

Impressions of Efficacy. There was no significant difference between those who order and those who do not in reports of the number of antiemetics that would be tried first before prescribing dronabinol. See Table AC.

Polypharmacy is still popular. Of those using dronabinol 58.3% (n - 60) used it in combination with other antiemetics. (Note that in our analysis of the combination study, little or no advantage in combination antiemetic therapy was actually found. See page 36.

The dronabinol prescribers have somewhat more favorable opinion of dronabinol's efficacy for nausea than have the non-prescribers in this survey. See figures I and 2.

The difference in opinion between the two groups of dronabinol's efficacy for vomiting is somewhat less. See figures 3 and 4.

Reasons to Hesitate to Prescribe Dronabinol

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

Non-prescribers Prescribers Total

n - 45 n - 103 n - 148

No. % No. % No. %

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

Side effects too severe 17 37.8 38 36.9 55 37.2

Not effective 14 31.1 26 25.2 40 27.0

Indications too limited 1 2.2 8 7.8 9 6.1

Requires Triplicate 3 6.7 22 21.4 25 16.9

Cost too high 6 13.3 27 26.2 33 22.3

Other 15 33.3 16 15.5 31 20.9

No response 5 11.1 15 14.6 20 13.5

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

Table AB

Main Reason for Participation in

Cannabis-Therapeutic-program

Prescribers Non-prescribers Total

n - 103 n - 45 n - 148

No. % No. % No. %

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

Contribute to

research 27 26.2 12 26.7 39 26.4

Patient demand 23 22.3 4 8.9 27 18.2

Provide compassionate

access 44 42.7 23 51.1 67 45.3

Other 1 1.0 2 4.4 3 2.0

No response 6 5.8 4 8.9 10 6.8

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

Table AC

Number of Antiemetics Prescribed

Before Prescribing Dronabinol

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

Prescribers Non-prescribers Total

n - 103 n - 45 n - 148

No. % No. % No. %

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

None 0 0 0

1 7 6.8 0 7 4.7

2 31 30.1 7 15.6 38 25.7

3 47 45.6 15 33.3 62 41.9

4 or more 17 16.5 14 31.1 31 20.9

No response 1 1.0 9 20.0 10 6.8


Evaluation of the Cannabis Therapeutic Program.

In general, our investigators were favorably disposed toward the Panel's efforts to carry out the objectives of the Cannabis Therapeutic Program. See figure 5.

Discussion of Results of Cannabis Therapeutic Program

A general consistency was noted in results of impression of effectiveness of THC and smoked marijuana as an antiemetic throughout the various protocols.

Side effects are significant, but were never observed to be life threatening. Clinically serious adverse reactions, defined as reactions while taking THC or marijuana that required the use of drugs or hospitalization of the patient, were observed primarily at the beginning of the study. Nine cases were reported during the first 1569 patients and only one throughout the balance of the study. This great reduction in severe side effects may be due to several factors: 1) The recommended initial dosage was first lowered from 7.5 to 5mg/m2. 2) Then, cumulative dosing technique was recommended. 3) Patients with metastes to the brain were excluded from the study. 4) Perhaps as the hospital staff became more familiar with the clinical use of this disinhibiting drug, they were better able to allay a feeling of panic in the inexperienced subjects.

The Panel noted a number of problems in the conduct of such a large multi-investigator study.

It is difficult to determine the degree of uniformity among investigators in their interpretation of 'Mild,' 'Moderate,& or 'Severe.In some cases the reports received from investigators were incomplete. In a few cases it was apparent that second and subsequent treatment reports were merely copies of prior reports. Treatment reports beyond the first were not extensively utilized in the Panel's analysis of data.

The requirements for compassionate access to THC and smoked marijuana made the use of a true control group impossible. The publicity given compassionate access somewhat reduced investigator compliance and reduced the strictness of Panel requirements. Nevertheless, a few investigators were dropped from the study due to lack of cooperation.

The attempt by the Panel to conduct smaller controlled studies within the overall Cannabis Therapeutic Program was inhibited by the lack of funds to provide physician investigators the financial incentive usually offered by industrial sponsors of new drug investigations.

In spite of the problems, the Panel has been able to gather valuable information on side effects of THC therapy and dosing approaches which will minimize these side effects. Also, even though this was not a formal, blinded, efficacy study the tabulation of reports of impression of effectiveness is a valuable predictor of the clinical future for this drug.

APPROVAL BY FDA FOR MARKETING OF THC

AND CONCLUSION

OF THE CANNABIS THERAPEUTIC PROGRAM


Approval and Rescheduling

The Federal Food and Drug Administration (FDA) required the same sequence of pre-marketing human trial a to demonstrate safety and effectiveness for THC as for any new drug. The Phase II, or controlled, double-blind studies, were previously reported in the literature. The Phase III studies that are represented by the Cannabis

Therapeutic Program's trials are uncontrolled, but involve a large number of patients. In this phase, the Panel provided the largest experience simulating conditions of actual practice, that is, the California Program was a successful Phase III study useful to the FDA. The Research Advisory Panel, its cooperative investigators and NCI's supply of investigational drug subsidized the marketing of dronabinol. Under the usual circumstances the cost for the data provided in such a study would have exceeded $1.5 million.

In 1985, the FDA concluded that the efficacy and safety of THC were well enough established to justify approval of dronabinol for marketing under highly restricted conditions. This action by the FDA did not immediately terminate the need for the compassionate access protocol. Approval jointly by the FDA and DEA of the use of THC for a single application and in a single dose form, i.e.. the oral capsule, did not override existing California laws and regulations.

In October 1986, both Federal and State laws and regulations were changed and THC, now classed as a Schedule II controlled substance and requiring the use of the California Triplicate Prescription Form, became available as a prescription drug marketed as dronabinol (Marinol). Thus, much of the need for the Cannabis Therapeutic Program ended.

During the transition period between FDA approval and the ultimate rescheduling of dronabinol (Marinol, THC) in California, the Panel minimized confusion by publishing pertinent information in the newsletters of various California licensing authorities and professional societies.

Investigational THC No Longer Supplied by NCI

The National Cancer Institute stopped supplying investigational THC after September 30, 1986; however, any investigational THC remaining in California pharmacies was available to approved investigators. The Panel monitored the use through August 1987, and audited the return to the DEA of unused supplies. At no time during the program were there any discrepancies in inventory or suspicion of diversion. It was occasionally necessary to require some investigators to file missing treatment reports (discovered by review of pharmacy records) by considering denial of investigational privileges.

Dronabinol finally became available as a Schedule II drug in California on October 1, 1986. It is important to note that only synthetic THC in sesame oil and encapsulated in a soft gelatin capsule has been rescheduled. Other forms of marijuana and THC remain Schedule I under both California and federal Controlled Substances laws.

The U.S. Drug Enforcement Administration has stressed that dronabinol should be prescribed only for its FDA-approved use: the treatment of nausea and vomiting associated with cancer chemotherapy in patients who have failed to respond adequately to conventional antiemetics. FDA labeling states that this restriction is required because a substantial proportion of patients treated with dronabinol can be expected to experience disturbing psychotomimetic reactions not observed with other antiemetic agents. The FDA-approved labeling also declares that dronabinol is contraindicated in patients whose nausea and vomiting arises from any cause other than cancer chemotherapy. DEA warned in its regulation which rescheduled dronabinol, that it may revoke a registrant's Schedule II license and pursue any criminal sanctions warranted under the Controlled Substances Act if a practitioner distributes or dispenses dronabinol in a manner that constitutes a threat to the public safety.

Investigators and pharmacies had been advised that marijuana cigarettes would continue to be available through the Panel's Smoked Marijuana Protocol at least through the end of 1988. In spite of this continued availability, there has been little or no interest in continued study of marijuana cigarettes by the Panel's investigators.


 

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